- Mar 03, 2025
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[ Upstream commit 638ba5089324796c2ee49af10427459c2de35f71 ] qdisc_tree_reduce_backlog() notifies parent qdisc only if child qdisc becomes empty, therefore we need to reduce the backlog of the child qdisc before calling it. Otherwise it would miss the opportunity to call cops->qlen_notify(), in the case of DRR, it resulted in UAF since DRR uses ->qlen_notify() to maintain its active list. Fixes: f8d4bc455047 ("net/sched: netem: account for backlog updates from child qdisc") Cc: Martin Ottens <martin.ottens@fau.de> Reported-by:Mingi Cho <mincho@theori.io> Signed-off-by:
Cong Wang <cong.wang@bytedance.com> Link: https://patch.msgid.link/20250204005841.223511-4-xiyou.wangcong@gmail.com Signed-off-by:
Jakub Kicinski <kuba@kernel.org> Signed-off-by:
Sasha Levin <sashal@kernel.org>
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[ Upstream commit bc50835e83f60f56e9bec2b392fb5544f250fb6f ] Lion Ackermann was able to create a UAF which can be abused for privilege escalation with the following script Step 1. create root qdisc tc qdisc add dev lo root handle 1:0 drr step2. a class for packet aggregation do demonstrate uaf tc class add dev lo classid 1:1 drr step3. a class for nesting tc class add dev lo classid 1:2 drr step4. a class to graft qdisc to tc class add dev lo classid 1:3 drr step5. tc qdisc add dev lo parent 1:1 handle 2:0 plug limit 1024 step6. tc qdisc add dev lo parent 1:2 handle 3:0 drr step7. tc class add dev lo classid 3:1 drr step 8. tc qdisc add dev lo parent 3:1 handle 4:0 pfifo step 9. Display the class/qdisc layout tc class ls dev lo class drr 1:1 root leaf 2: quantum 64Kb class drr 1:2 root leaf 3: quantum 64Kb class drr 3:1 root leaf 4: quantum 64Kb tc qdisc ls qdisc drr 1: dev lo root refcnt 2 qdisc plug 2: dev lo parent 1:1 qdisc pfifo 4: dev lo parent 3:1 limit 1000p qdisc drr 3: dev lo parent 1:2 step10. trigger the bug <=== prevented by this patch tc qdisc replace dev lo parent 1:3 handle 4:0 step 11. Redisplay again the qdiscs/classes tc class ls dev lo class drr 1:1 root leaf 2: quantum 64Kb class drr 1:2 root leaf 3: quantum 64Kb class drr 1:3 root leaf 4: quantum 64Kb class drr 3:1 root leaf 4: quantum 64Kb tc qdisc ls qdisc drr 1: dev lo root refcnt 2 qdisc plug 2: dev lo parent 1:1 qdisc pfifo 4: dev lo parent 3:1 refcnt 2 limit 1000p qdisc drr 3: dev lo parent 1:2 Observe that a) parent for 4:0 does not change despite the replace request. There can only be one parent. b) refcount has gone up by two for 4:0 and c) both class 1:3 and 3:1 are pointing to it. Step 12. send one packet to plug echo "" | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888,priority=$((0x10001)) step13. send one packet to the grafted fifo echo "" | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888,priority=$((0x10003)) step14. lets trigger the uaf tc class delete dev lo classid 1:3 tc class delete dev lo classid 1:1 The semantics of "replace" is for a del/add _on the same node_ and not a delete from one node(3:1) and add to another node (1:3) as in step10. While we could "fix" with a more complex approach there could be consequences to expectations so the patch takes the preventive approach of "disallow such config". Joint work with Lion Ackermann <nnamrec@gmail.com> Fixes: 1da177e4 ("Linux-2.6.12-rc2") Signed-off-by:
Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by:
Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250116013713.900000-1-kuba@kernel.org Signed-off-by:
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[ Upstream commit 10685681bafce6febb39770f3387621bf5d67d0b ] The current implementation does not work correctly with a limit of 1. iproute2 actually checks for this and this patch adds the check in kernel as well. This fixes the following syzkaller reported crash: UBSAN: array-index-out-of-bounds in net/sched/sch_sfq.c:210:6 index 65535 is out of range for type 'struct sfq_head[128]' CPU: 0 PID: 2569 Comm: syz-executor101 Not tainted 5.10.0-smp-DEV #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x125/0x19f lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:148 [inline] __ubsan_handle_out_of_bounds+0xed/0x120 lib/ubsan.c:347 sfq_link net/sched/sch_sfq.c:210 [inline] sfq_dec+0x528/0x600 net/sched/sch_sfq.c:238 sfq_dequeue+0x39b/0x9d0 net/sched/sch_sfq.c:500 sfq_reset+0x13/0x50 net/sched/sch_sfq.c:525 qdisc_reset+0xfe/0x510 net/sched/sch_generic.c:1026 tbf_reset+0x3d/0x100 net/sched/sch_tbf.c:319 qdisc_reset+0xfe/0x510 net/sched/sch_generic.c:1026 dev_reset_queue+0x8c/0x140 net/sched/sch_generic.c:1296 netdev_for_each_tx_queue include/linux/netdevice.h:2350 [inline] dev_deactivate_many+0x6dc/0xc20 net/sched/sch_generic.c:1362 __dev_close_many+0x214/0x350 net/core/dev.c:1468 dev_close_many+0x207/0x510 net/core/dev.c:1506 unregister_netdevice_many+0x40f/0x16b0 net/core/dev.c:10738 unregister_netdevice_queue+0x2be/0x310 net/core/dev.c:10695 unregister_netdevice include/linux/netdevice.h:2893 [inline] __tun_detach+0x6b6/0x1600 drivers/net/tun.c:689 tun_detach drivers/net/tun.c:705 [inline] tun_chr_close+0x104/0x1b0 drivers/net/tun.c:3640 __fput+0x203/0x840 fs/file_table.c:280 task_work_run+0x129/0x1b0 kernel/task_work.c:185 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x5ce/0x2200 kernel/exit.c:931 do_group_exit+0x144/0x310 kernel/exit.c:1046 __do_sys_exit_group kernel/exit.c:1057 [inline] __se_sys_exit_group kernel/exit.c:1055 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1055 do_syscall_64+0x6c/0xd0 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fe5e7b52479 Code: Unable to access opcode bytes at RIP 0x7fe5e7b5244f. RSP: 002b:00007ffd3c800398 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe5e7b52479 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 00007fe5e7bcd2d0 R08: ffffffffffffffb8 R09: 0000000000000014 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe5e7bcd2d0 R13: 0000000000000000 R14: 00007fe5e7bcdd20 R15: 00007fe5e7b24270 The crash can be also be reproduced with the following (with a tc recompiled to allow for sfq limits of 1): tc qdisc add dev dummy0 handle 1: root tbf rate 1Kbit burst 100b lat 1s ../iproute2-6.9.0/tc/tc qdisc add dev dummy0 handle 2: parent 1:10 sfq limit 1 ifconfig dummy0 up ping -I dummy0 -f -c2 -W0.1 8.8.8.8 sleep 1 Scenario that triggers the crash: * the first packet is sent and queued in TBF and SFQ; qdisc qlen is 1 * TBF dequeues: it peeks from SFQ which moves the packet to the gso_skb list and keeps qdisc qlen set to 1. TBF is out of tokens so it schedules itself for later. * the second packet is sent and TBF tries to queues it to SFQ. qdisc qlen is now 2 and because the SFQ limit is 1 the packet is dropped by SFQ. At this point qlen is 1, and all of the SFQ slots are empty, however q->tail is not NULL. At this point, assuming no more packets are queued, when sch_dequeue runs again it will decrement the qlen for the current empty slot causing an underflow and the subsequent out of bounds access. Reported-by:
syzbot <syzkaller@googlegroups.com> Fixes: 1da177e4 ("Linux-2.6.12-rc2") Signed-off-by:
Octavian Purdila <tavip@google.com> Reviewed-by:
Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20241204030520.2084663-2-tavip@google.com Signed-off-by:
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[ Upstream commit e4650d7ae4252f67e997a632adfae0dd74d3a99a ] SFQ has an assumption on dealing with packets smaller than 64KB. Even before BIG TCP, TCA_STAB can provide arbitrary big values in qdisc_pkt_len(skb) It is time to switch (struct sfq_slot)->allot to a 32bit field. sizeof(struct sfq_slot) is now 64 bytes, giving better cache locality. Signed-off-by:
Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20241008111603.653140-1-edumazet@google.com Signed-off-by:
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[ Upstream commit a17ef9e6 ] sfq_perturbation() reads q->perturb_period locklessly. Add annotations to fix potential issues. Signed-off-by:
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- Feb 03, 2025
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commit d62b04fca4340a0d468d7853bd66e511935a18cb upstream. Haowei Yan <g1042620637@gmail.com> found that ets_class_from_arg() can index an Out-Of-Bound class in ets_class_from_arg() when passed clid of 0. The overflow may cause local privilege escalation. [ 18.852298] ------------[ cut here ]------------ [ 18.853271] UBSAN: array-index-out-of-bounds in net/sched/sch_ets.c:93:20 [ 18.853743] index 18446744073709551615 is out of range for type 'ets_class [16]' [ 18.854254] CPU: 0 UID: 0 PID: 1275 Comm: poc Not tainted 6.12.6-dirty #17 [ 18.854821] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 18.856532] Call Trace: [ 18.857441] <TASK> [ 18.858227] dump_stack_lvl+0xc2/0xf0 [ 18.859607] dump_stack+0x10/0x20 [ 18.860908] __ubsan_handle_out_of_bounds+0xa7/0xf0 [ 18.864022] ets_class_change+0x3d6/0x3f0 [ 18.864322] tc_ctl_tclass+0x251/0x910 [ 18.864587] ? lock_acquire+0x5e/0x140 [ 18.865113] ? __mutex_lock+0x9c/0xe70 [ 18.866009] ? __mutex_lock+0xa34/0xe70 [ 18.866401] rtnetlink_rcv_msg+0x170/0x6f0 [ 18.866806] ? __lock_acquire+0x578/0xc10 [ 18.867184] ? __pfx_rtnetlink_rcv_msg+0x10/0x10 [ 18.867503] netlink_rcv_skb+0x59/0x110 [ 18.867776] rtnetlink_rcv+0x15/0x30 [ 18.868159] netlink_unicast+0x1c3/0x2b0 [ 18.868440] netlink_sendmsg+0x239/0x4b0 [ 18.868721] ____sys_sendmsg+0x3e2/0x410 [ 18.869012] ___sys_sendmsg+0x88/0xe0 [ 18.869276] ? rseq_ip_fixup+0x198/0x260 [ 18.869563] ? rseq_update_cpu_node_id+0x10a/0x190 [ 18.869900] ? trace_hardirqs_off+0x5a/0xd0 [ 18.870196] ? syscall_exit_to_user_mode+0xcc/0x220 [ 18.870547] ? do_syscall_64+0x93/0x150 [ 18.870821] ? __memcg_slab_free_hook+0x69/0x290 [ 18.871157] __sys_sendmsg+0x69/0xd0 [ 18.871416] __x64_sys_sendmsg+0x1d/0x30 [ 18.871699] x64_sys_call+0x9e2/0x2670 [ 18.871979] do_syscall_64+0x87/0x150 [ 18.873280] ? do_syscall_64+0x93/0x150 [ 18.874742] ? lock_release+0x7b/0x160 [ 18.876157] ? do_user_addr_fault+0x5ce/0x8f0 [ 18.877833] ? irqentry_exit_to_user_mode+0xc2/0x210 [ 18.879608] ? irqentry_exit+0x77/0xb0 [ 18.879808] ? clear_bhb_loop+0x15/0x70 [ 18.880023] ? clear_bhb_loop+0x15/0x70 [ 18.880223] ? clear_bhb_loop+0x15/0x70 [ 18.880426] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 18.880683] RIP: 0033:0x44a957 [ 18.880851] Code: ff ff e8 fc 00 00 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 8974 24 10 [ 18.881766] RSP: 002b:00007ffcdd00fad8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 18.882149] RAX: ffffffffffffffda RBX: 00007ffcdd010db8 RCX: 000000000044a957 [ 18.882507] RDX: 0000000000000000 RSI: 00007ffcdd00fb70 RDI: 0000000000000003 [ 18.885037] RBP: 00007ffcdd010bc0 R08: 000000000703c770 R09: 000000000703c7c0 [ 18.887203] R10: 0000000000000080 R11: 0000000000000246 R12: 0000000000000001 [ 18.888026] R13: 00007ffcdd010da8 R14: 00000000004ca7d0 R15: 0000000000000001 [ 18.888395] </TASK> [ 18.888610] ---[ end trace ]--- Fixes: dcc68b4d ("net: sch_ets: Add a new Qdisc") Reported-by:
Haowei Yan <g1042620637@gmail.com> Suggested-by:
Petr Machata <petrm@nvidia.com> Link: https://patch.msgid.link/20250111145740.74755-1-jhs@mojatatu.com Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 737d4d91d35b5f7fa5bb442651472277318b0bfd ] Even though we fixed a logic error in the commit cited below, syzbot still managed to trigger an underflow of the per-host bulk flow counters, leading to an out of bounds memory access. To avoid any such logic errors causing out of bounds memory accesses, this commit factors out all accesses to the per-host bulk flow counters to a series of helpers that perform bounds-checking before any increments and decrements. This also has the benefit of improving readability by moving the conditional checks for the flow mode into these helpers, instead of having them spread out throughout the code (which was the cause of the original logic error). As part of this change, the flow quantum calculation is consolidated into a helper function, which means that the dithering applied to the ost load scaling is now applied both in the DRR rotation and when a sparse flow's quantum is first initiated. The only user-visible effect of this is that the maximum packet size that can be sent while a flow stays sparse will now vary with +/- one byte in some cases. This should not make a noticeable difference in practice, and thus it's not worth complicating the code to preserve the old behaviour. Fixes: 546ea84d ("sched: sch_cake: fix bulk flow accounting logic for host fairness") Reported-by:
<syzbot+f63600d288bfb7057424@syzkaller.appspotmail.com> Signed-off-by:
Dave Taht <dave.taht@gmail.com> Link: https://patch.msgid.link/20250107120105.70685-1-toke@redhat.com Signed-off-by:
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[ Upstream commit a039e54397c6a75b713b9ce7894a62e06956aa92 ] syzbot found that TCA_FLOW_RSHIFT attribute was not validated. Right shitfing a 32bit integer is undefined for large shift values. UBSAN: shift-out-of-bounds in net/sched/cls_flow.c:329:23 shift exponent 9445 is too large for 32-bit type 'u32' (aka 'unsigned int') CPU: 1 UID: 0 PID: 54 Comm: kworker/u8:3 Not tainted 6.13.0-rc3-syzkaller-00180-g4f619d518db9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:231 [inline] __ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:468 flow_classify+0x24d5/0x25b0 net/sched/cls_flow.c:329 tc_classify include/net/tc_wrapper.h:197 [inline] __tcf_classify net/sched/cls_api.c:1771 [inline] tcf_classify+0x420/0x1160 net/sched/cls_api.c:1867 sfb_classify net/sched/sch_sfb.c:260 [inline] sfb_enqueue+0x3ad/0x18b0 net/sched/sch_sfb.c:318 dev_qdisc_enqueue+0x4b/0x290 net/core/dev.c:3793 __dev_xmit_skb net/core/dev.c:3889 [inline] __dev_queue_xmit+0xf0e/0x3f50 net/core/dev.c:4400 dev_queue_xmit include/linux/netdevice.h:3168 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:236 iptunnel_xmit+0x55d/0x9b0 net/ipv4/ip_tunnel_core.c:82 udp_tunnel_xmit_skb+0x262/0x3b0 net/ipv4/udp_tunnel_core.c:173 geneve_xmit_skb drivers/net/geneve.c:916 [inline] geneve_xmit+0x21dc/0x2d00 drivers/net/geneve.c:1039 __netdev_start_xmit include/linux/netdevice.h:5002 [inline] netdev_start_xmit include/linux/netdevice.h:5011 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x27a/0x7d0 net/core/dev.c:3606 __dev_queue_xmit+0x1b73/0x3f50 net/core/dev.c:4434 Fixes: e5dfb815 ("[NET_SCHED]: Add flow classifier") Reported-by:
<syzbot+1dbb57d994e54aaa04d2@syzkaller.appspotmail.com> Closes: https://lore.kernel.org/netdev/6777bf49.050a0220.178762.0040.GAE@google.com/T/#u Signed-off-by:
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- Jan 14, 2025
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commit 5eb7de8cd58e73851cd37ff8d0666517d9926948 upstream. Changes to sch->q.qlen around qdisc_tree_reduce_backlog() need to happen _before_ a call to said function because otherwise it may fail to notify parent qdiscs when the child is about to become empty. Signed-off-by:
Lion Ackermann <nnamrec@gmail.com> Acked-by:
Toke Høiland-Jørgensen <toke@toke.dk> Signed-off-by:
David S. Miller <davem@davemloft.net> Cc: Artem Metla <ametla@google.com> Signed-off-by:
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[ Upstream commit f8d4bc455047cf3903cd6f85f49978987dbb3027 ] In general, 'qlen' of any classful qdisc should keep track of the number of packets that the qdisc itself and all of its children holds. In case of netem, 'qlen' only accounts for the packets in its internal tfifo. When netem is used with a child qdisc, the child qdisc can use 'qdisc_tree_reduce_backlog' to inform its parent, netem, about created or dropped SKBs. This function updates 'qlen' and the backlog statistics of netem, but netem does not account for changes made by a child qdisc. 'qlen' then indicates the wrong number of packets in the tfifo. If a child qdisc creates new SKBs during enqueue and informs its parent about this, netem's 'qlen' value is increased. When netem dequeues the newly created SKBs from the child, the 'qlen' in netem is not updated. If 'qlen' reaches the configured sch->limit, the enqueue function stops working, even though the tfifo is not full. Reproduce the bug: Ensure that the sender machine has GSO enabled. Configure netem as root qdisc and tbf as its child on the outgoing interface of the machine as follows: $ tc qdisc add dev <oif> root handle 1: netem delay 100ms limit 100 $ tc qdisc add dev <oif> parent 1:0 tbf rate 50Mbit burst 1542 latency 50ms Send bulk TCP traffic out via this interface, e.g., by running an iPerf3 client on the machine. Check the qdisc statistics: $ tc -s qdisc show dev <oif> Statistics after 10s of iPerf3 TCP test before the fix (note that netem's backlog > limit, netem stopped accepting packets): qdisc netem 1: root refcnt 2 limit 1000 delay 100ms Sent 2767766 bytes 1848 pkt (dropped 652, overlimits 0 requeues 0) backlog 4294528236b 1155p requeues 0 qdisc tbf 10: parent 1:1 rate 50Mbit burst 1537b lat 50ms Sent 2767766 bytes 1848 pkt (dropped 327, overlimits 7601 requeues 0) backlog 0b 0p requeues 0 Statistics after the fix: qdisc netem 1: root refcnt 2 limit 1000 delay 100ms Sent 37766372 bytes 24974 pkt (dropped 9, overlimits 0 requeues 0) backlog 0b 0p requeues 0 qdisc tbf 10: parent 1:1 rate 50Mbit burst 1537b lat 50ms Sent 37766372 bytes 24974 pkt (dropped 327, overlimits 96017 requeues 0) backlog 0b 0p requeues 0 tbf segments the GSO SKBs (tbf_segment) and updates the netem's 'qlen'. The interface fully stops transferring packets and "locks". In this case, the child qdisc and tfifo are empty, but 'qlen' indicates the tfifo is at its limit and no more packets are accepted. This patch adds a counter for the entries in the tfifo. Netem's 'qlen' is only decreased when a packet is returned by its dequeue function, and not during enqueuing into the child qdisc. External updates to 'qlen' are thus accounted for and only the behavior of the backlog statistics changes. As in other qdiscs, 'qlen' then keeps track of how many packets are held in netem and all of its children. As before, sch->limit remains as the maximum number of packets in the tfifo. The same applies to netem's backlog statistics. Fixes: 50612537 ("netem: fix classful handling") Signed-off-by:
Martin Ottens <martin.ottens@fau.de> Acked-by:
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[ Upstream commit 397006ba5d918f9b74e734867e8fddbc36dc2282 ] The subsequent calculation of port_rate = speed * 1000 * BYTES_PER_KBIT, where the BYTES_PER_KBIT is of type LL, may cause an overflow. At least when speed = SPEED_20000, the expression to the left of port_rate will be greater than INT_MAX. Found by Linux Verification Center (linuxtesting.org) with SVACE. Signed-off-by:
Elena Salomatkina <esalomatkina@ispras.ru> Link: https://patch.msgid.link/20241013124529.1043-1-esalomatkina@ispras.ru Signed-off-by:
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[ Upstream commit 292207809486d99c78068d3f459cbbbffde88415 ] When matching erspan_opt in cls_flower, only the (version, dir, hwid) fields are relevant. However, in fl_set_erspan_opt() it initializes all bits of erspan_opt and its mask to 1. This inadvertently requires packets to match not only the (version, dir, hwid) fields but also the other fields that are unexpectedly set to 1. This patch resolves the issue by ensuring that only the (version, dir, hwid) fields are configured in fl_set_erspan_opt(), leaving the other fields to 0 in erspan_opt. Fixes: 79b1011c ("net: sched: allow flower to match erspan options") Reported-by:
Shuang Li <shuali@redhat.com> Signed-off-by:
Xin Long <lucien.xin@gmail.com> Reviewed-by:
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[ Upstream commit 1596a135e3180c92e42dd1fbcad321f4fb3e3b17 ] When the length of a GSO packet in the tbf qdisc is larger than the burst size configured the packet will be segmented by the tbf_segment function. Whenever this function is used to enqueue SKBs, the backlog statistic of the tbf is not increased correctly. This can lead to underflows of the 'backlog' byte-statistic value when these packets are dequeued from tbf. Reproduce the bug: Ensure that the sender machine has GSO enabled. Configured the tbf on the outgoing interface of the machine as follows (burstsize = 1 MTU): $ tc qdisc add dev <oif> root handle 1: tbf rate 50Mbit burst 1514 latency 50ms Send bulk TCP traffic out via this interface, e.g., by running an iPerf3 client on this machine. Check the qdisc statistics: $ tc -s qdisc show dev <oif> The 'backlog' byte-statistic has incorrect values while traffic is transferred, e.g., high values due to u32 underflows. When the transfer is stopped, the value is != 0, which should never happen. This patch fixes this bug by updating the statistics correctly, even if single SKBs of a GSO SKB cannot be enqueued. Fixes: e43ac79a ("sch_tbf: segment too big GSO packets") Signed-off-by:
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[ Upstream commit b4cb4a13 ] Toke mentioned unrcu_pointer() existence, allowing to remove some of the ugly casts we have when using xchg() for rcu protected pointers. Also make inet_rcv_compat const. Signed-off-by:
Paolo Abeni <pabeni@redhat.com> Stable-dep-of: eb02688c5c45 ("ipv6: release nexthop on device removal") Signed-off-by:
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[ Upstream commit fb66df20 ] It is possible for syzbot to side-step the restriction imposed by the blamed commit in the Fixes: tag, because the taprio UAPI permits a cycle-time different from (and potentially shorter than) the sum of entry intervals. We need one more restriction, which is that the cycle time itself must be larger than N * ETH_ZLEN bit times, where N is the number of schedule entries. This restriction needs to apply regardless of whether the cycle time came from the user or was the implicit, auto-calculated value, so we move the existing "cycle == 0" check outside the "if "(!new->cycle_time)" branch. This way covers both conditions and scenarios. Add a selftest which illustrates the issue triggered by syzbot. Fixes: b5b73b26 ("taprio: Fix allowing too small intervals") Reported-by:
<syzbot+a7d2b1d5d1af83035567@syzkaller.appspotmail.com> Closes: https://lore.kernel.org/netdev/0000000000007d66bc06196e7c66@google.com/ Signed-off-by:
Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/r/20240527153955.553333-2-vladimir.oltean@nxp.com Signed-off-by:
Xiangyu Chen <xiangyu.chen@windriver.com> Signed-off-by:
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[ Upstream commit 73af53d8 ] To generate hnode handles (in gen_new_htid()), u32 uses IDR and encodes the returned small integer into a structured 32-bit word. Unfortunately, at disposal time, the needed decoding is not done. As a result, idr_remove() fails, and the IDR fills up. Since its size is 2048, the following script ends up with "Filter already exists": tc filter add dev myve $FILTER1 tc filter add dev myve $FILTER2 for i in {1..2048} do echo $i tc filter del dev myve $FILTER2 tc filter add dev myve $FILTER2 done This patch adds the missing decoding logic for handles that deserve it. Fixes: e7614370 ("net_sched: use idr to allocate u32 filter handles") Reviewed-by:
Alexandre Ferrieux <alexandre.ferrieux@orange.com> Tested-by:
Victor Nogueira <victor@mojatatu.com> Link: https://patch.msgid.link/20241110172836.331319-1-alexandre.ferrieux@orange.com Signed-off-by:
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[ Upstream commit 6b78debe ] Proper refcounts will always warn splat when something goes wrong, be it underflow, saturation or object resurrection. As these are always a source of bugs, use it in cls_u32 as a safeguard to prevent/catch issues. Another benefit is that the refcount API self documents the code, making clear when transitions to dead are expected. For such an update we had to make minor adaptations on u32 to fit the refcount API. First we set explicitly to '1' when objects are created, then the objects are alive until a 1 -> 0 happens, which is then released appropriately. The above made clear some redundant operations in the u32 code around the root_ht handling that were removed. The root_ht is created with a refcnt set to 1. Then when it's associated with tcf_proto it increments the refcnt to 2. Throughout the entire code the root_ht is an exceptional case and can never be referenced, therefore the refcnt never incremented/decremented. Its lifetime is always bound to tcf_proto, meaning if you delete tcf_proto the root_ht is deleted as well. The code made up for the fact that root_ht refcnt is 2 and did a double decrement to free it, which is not a fit for the refcount API. Even though refcount_t is implemented using atomics, we should observe a negligible control plane impact. Signed-off-by:
Pedro Tammela <pctammela@mojatatu.com> Acked-by:
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commit b22db8b8 upstream. Fix possible use-after-free in 'taprio_dump()' by adding RCU read-side critical section there. Never seen on x86 but found on a KASAN-enabled arm64 system when investigating https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa : [T15862] BUG: KASAN: slab-use-after-free in taprio_dump+0xa0c/0xbb0 [T15862] Read of size 4 at addr ffff0000d4bb88f8 by task repro/15862 [T15862] [T15862] CPU: 0 UID: 0 PID: 15862 Comm: repro Not tainted 6.11.0-rc1-00293-gdefaf1a2113a-dirty #2 [T15862] Hardware name: QEMU QEMU Virtual Machine, BIOS edk2-20240524-5.fc40 05/24/2024 [T15862] Call trace: [T15862] dump_backtrace+0x20c/0x220 [T15862] show_stack+0x2c/0x40 [T15862] dump_stack_lvl+0xf8/0x174 [T15862] print_report+0x170/0x4d8 [T15862] kasan_report+0xb8/0x1d4 [T15862] __asan_report_load4_noabort+0x20/0x2c [T15862] taprio_dump+0xa0c/0xbb0 [T15862] tc_fill_qdisc+0x540/0x1020 [T15862] qdisc_notify.isra.0+0x330/0x3a0 [T15862] tc_modify_qdisc+0x7b8/0x1838 [T15862] rtnetlink_rcv_msg+0x3c8/0xc20 [T15862] netlink_rcv_skb+0x1f8/0x3d4 [T15862] rtnetlink_rcv+0x28/0x40 [T15862] netlink_unicast+0x51c/0x790 [T15862] netlink_sendmsg+0x79c/0xc20 [T15862] __sock_sendmsg+0xe0/0x1a0 [T15862] ____sys_sendmsg+0x6c0/0x840 [T15862] ___sys_sendmsg+0x1ac/0x1f0 [T15862] __sys_sendmsg+0x110/0x1d0 [T15862] __arm64_sys_sendmsg+0x74/0xb0 [T15862] invoke_syscall+0x88/0x2e0 [T15862] el0_svc_common.constprop.0+0xe4/0x2a0 [T15862] do_el0_svc+0x44/0x60 [T15862] el0_svc+0x50/0x184 [T15862] el0t_64_sync_handler+0x120/0x12c [T15862] el0t_64_sync+0x190/0x194 [T15862] [T15862] Allocated by task 15857: [T15862] kasan_save_stack+0x3c/0x70 [T15862] kasan_save_track+0x20/0x3c [T15862] kasan_save_alloc_info+0x40/0x60 [T15862] __kasan_kmalloc+0xd4/0xe0 [T15862] __kmalloc_cache_noprof+0x194/0x334 [T15862] taprio_change+0x45c/0x2fe0 [T15862] tc_modify_qdisc+0x6a8/0x1838 [T15862] rtnetlink_rcv_msg+0x3c8/0xc20 [T15862] netlink_rcv_skb+0x1f8/0x3d4 [T15862] rtnetlink_rcv+0x28/0x40 [T15862] netlink_unicast+0x51c/0x790 [T15862] netlink_sendmsg+0x79c/0xc20 [T15862] __sock_sendmsg+0xe0/0x1a0 [T15862] ____sys_sendmsg+0x6c0/0x840 [T15862] ___sys_sendmsg+0x1ac/0x1f0 [T15862] __sys_sendmsg+0x110/0x1d0 [T15862] __arm64_sys_sendmsg+0x74/0xb0 [T15862] invoke_syscall+0x88/0x2e0 [T15862] el0_svc_common.constprop.0+0xe4/0x2a0 [T15862] do_el0_svc+0x44/0x60 [T15862] el0_svc+0x50/0x184 [T15862] el0t_64_sync_handler+0x120/0x12c [T15862] el0t_64_sync+0x190/0x194 [T15862] [T15862] Freed by task 6192: [T15862] kasan_save_stack+0x3c/0x70 [T15862] kasan_save_track+0x20/0x3c [T15862] kasan_save_free_info+0x4c/0x80 [T15862] poison_slab_object+0x110/0x160 [T15862] __kasan_slab_free+0x3c/0x74 [T15862] kfree+0x134/0x3c0 [T15862] taprio_free_sched_cb+0x18c/0x220 [T15862] rcu_core+0x920/0x1b7c [T15862] rcu_core_si+0x10/0x1c [T15862] handle_softirqs+0x2e8/0xd64 [T15862] __do_softirq+0x14/0x20 Fixes: 18cdd2f0 ("net/sched: taprio: taprio_dump and taprio_change are protected by rtnl_mutex") Acked-by:
Vinicius Costa Gomes <vinicius.gomes@intel.com> Signed-off-by:
Dmitry Antipov <dmantipov@yandex.ru> Link: https://patch.msgid.link/20241018051339.418890-2-dmantipov@yandex.ru Signed-off-by:
Lee Jones <lee@kernel.org> Signed-off-by:
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[ Upstream commit 2e95c438 ] In qdisc_tree_reduce_backlog, Qdiscs with major handle ffff: are assumed to be either root or ingress. This assumption is bogus since it's valid to create egress qdiscs with major handle ffff: Budimir Markovic found that for qdiscs like DRR that maintain an active class list, it will cause a UAF with a dangling class pointer. In 066a3b5b, the concern was to avoid iterating over the ingress qdisc since its parent is itself. The proper fix is to stop when parent TC_H_ROOT is reached because the only way to retrieve ingress is when a hierarchy which does not contain a ffff: major handle call into qdisc_lookup with TC_H_MAJ(TC_H_ROOT). In the scenario where major ffff: is an egress qdisc in any of the tree levels, the updates will also propagate to TC_H_ROOT, which then the iteration must stop. Fixes: 066a3b5b ("[NET_SCHED] sch_api: fix qdisc_tree_decrease_qlen() loop") Reported-by:
Budimir Markovic <markovicbudimir@gmail.com> Suggested-by:
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[ Upstream commit f5044659 ] In 'taprio_change()', 'admin' pointer may become dangling due to sched switch / removal caused by 'advance_sched()', and critical section protected by 'q->current_entry_lock' is too small to prevent from such a scenario (which causes use-after-free detected by KASAN). Fix this by prefer 'rcu_replace_pointer()' over 'rcu_assign_pointer()' to update 'admin' immediately before an attempt to schedule freeing. Fixes: a3d43c0d ("taprio: Add support adding an admin schedule") Reported-by:
<syzbot+b65e0af58423fc8a73aa@syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa Acked-by:
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[ Upstream commit 34d35b4e ] tcf_action_init() has logic for checking mismatches between action and filter offload flags (skip_sw/skip_hw). AFAIU, this is intended to run on the transition between the new tc_act_bind(flags) returning true (aka now gets bound to classifier) and tc_act_bind(act->tcfa_flags) returning false (aka action was not bound to classifier before). Otherwise, the check is skipped. For the case where an action is not standalone, but rather it was created by a classifier and is bound to it, tcf_action_init() skips the check entirely, and this means it allows mismatched flags to occur. Taking the matchall classifier code path as an example (with mirred as an action), the reason is the following: 1 | mall_change() 2 | -> mall_replace_hw_filter() 3 | -> tcf_exts_validate_ex() 4 | -> flags |= TCA_ACT_FLAGS_BIND; 5 | -> tcf_action_init() 6 | -> tcf_action_init_1() 7 | -> a_o->init() 8 | -> tcf_mirred_init() 9 | -> tcf_idr_create_from_flags() 10 | -> tcf_idr_create() 11 | -> p->tcfa_flags = flags; 12 | -> tc_act_bind(flags)) 13 | -> tc_act_bind(act->tcfa_flags) When invoked from tcf_exts_validate_ex() like matchall does (but other classifiers validate their extensions as well), tcf_action_init() runs in a call path where "flags" always contains TCA_ACT_FLAGS_BIND (set by line 4). So line 12 is always true, and line 13 is always true as well. No transition ever takes place, and the check is skipped. The code was added in this form in commit c86e0209 ("flow_offload: validate flags of filter and actions"), but I'm attributing the blame even earlier in that series, to when TCA_ACT_FLAGS_SKIP_HW and TCA_ACT_FLAGS_SKIP_SW were added to the UAPI. Following the development process of this change, the check did not always exist in this form. A change took place between v3 [1] and v4 [2], AFAIU due to review feedback that it doesn't make sense for action flags to be different than classifier flags. I think I agree with that feedback, but it was translated into code that omits enforcing this for "classic" actions created at the same time with the filters themselves. There are 3 more important cases to discuss. First there is this command: $ tc qdisc add dev eth0 clasct $ tc filter add dev eth0 ingress matchall skip_sw \ action mirred ingress mirror dev eth1 which should be allowed, because prior to the concept of dedicated action flags, it used to work and it used to mean the action inherited the skip_sw/skip_hw flags from the classifier. It's not a mismatch. Then we have this command: $ tc qdisc add dev eth0 clasct $ tc filter add dev eth0 ingress matchall skip_sw \ action mirred ingress mirror dev eth1 skip_hw where there is a mismatch and it should be rejected. Finally, we have: $ tc qdisc add dev eth0 clasct $ tc filter add dev eth0 ingress matchall skip_sw \ action mirred ingress mirror dev eth1 skip_sw where the offload flags coincide, and this should be treated the same as the first command based on inheritance, and accepted. [1]: https://lore.kernel.org/netdev/20211028110646.13791-9-simon.horman@corigine.com/ [2]: https://lore.kernel.org/netdev/20211118130805.23897-10-simon.horman@corigine.com/ Fixes: 7adc5765 ("flow_offload: add skip_hw and skip_sw to control if offload the action") Signed-off-by:
Ido Schimmel <idosch@nvidia.com> Tested-by:
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[ Upstream commit 95ecba62 ] Some workloads hit the infamous dev_watchdog() message: "NETDEV WATCHDOG: eth0 (xxxx): transmit queue XX timed out" It seems possible to hit this even for perfectly normal BQL enabled drivers: 1) Assume a TX queue was idle for more than dev->watchdog_timeo (5 seconds unless changed by the driver) 2) Assume a big packet is sent, exceeding current BQL limit. 3) Driver ndo_start_xmit() puts the packet in TX ring, and netdev_tx_sent_queue() is called. 4) QUEUE_STATE_STACK_XOFF could be set from netdev_tx_sent_queue() before txq->trans_start has been written. 5) txq->trans_start is written later, from netdev_start_xmit() if (rc == NETDEV_TX_OK) txq_trans_update(txq) dev_watchdog() running on another cpu could read the old txq->trans_start, and then see QUEUE_STATE_STACK_XOFF, because 5) did not happen yet. To solve the issue, write txq->trans_start right before one XOFF bit is set : - _QUEUE_STATE_DRV_XOFF from netif_tx_stop_queue() - __QUEUE_STATE_STACK_XOFF from netdev_tx_sent_queue() From dev_watchdog(), we have to read txq->state before txq->trans_start. Add memory barriers to enforce correct ordering. In the future, we could avoid writing over txq->trans_start for normal operations, and rename this field to txq->xoff_start_time. Fixes: bec251bc ("net: no longer stop all TX queues in dev_watchdog()") Signed-off-by:
Willem de Bruijn <willemb@google.com> Reviewed-by:
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[ Upstream commit 33fb988b ] Applications are sensitive to long network latency, particularly heartbeat monitoring ones. Longer the tx timeout recovery higher the risk with such applications on a production machines. This patch remedies, yet honoring device set tx timeout. Modify watchdog next timeout to be shorter than the device specified. Compute the next timeout be equal to device watchdog timeout less the how long ago queue stop had been done. At next watchdog timeout tx timeout handler is called into if still in stopped state. Either called or not called, restore the watchdog timeout back to device specified. Signed-off-by:
Praveen Kumar Kannoju <praveen.kannoju@oracle.com> Link: https://lore.kernel.org/r/20240508133617.4424-1-praveen.kannoju@oracle.com Signed-off-by:
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[ Upstream commit 3cb7cf15 ] Most qdiscs maintain their backlog using qdisc_pkt_len(skb) on the assumption it is invariant between the enqueue() and dequeue() handlers. Unfortunately syzbot can crash a host rather easily using a TBF + SFQ combination, with an STAB on SFQ [1] We can't support TCA_STAB on arbitrary level, this would require to maintain per-qdisc storage. [1] [ 88.796496] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 88.798611] #PF: supervisor read access in kernel mode [ 88.799014] #PF: error_code(0x0000) - not-present page [ 88.799506] PGD 0 P4D 0 [ 88.799829] Oops: Oops: 0000 [#1] SMP NOPTI [ 88.800569] CPU: 14 UID: 0 PID: 2053 Comm: b371744477 Not tainted 6.12.0-rc1-virtme #1117 [ 88.801107] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 88.801779] RIP: 0010:sfq_dequeue (net/sched/sch_sfq.c:272 net/sched/sch_sfq.c:499) sch_sfq [ 88.802544] Code: 0f b7 50 12 48 8d 04 d5 00 00 00 00 48 89 d6 48 29 d0 48 8b 91 c0 01 00 00 48 c1 e0 03 48 01 c2 66 83 7a 1a 00 7e c0 48 8b 3a <4c> 8b 07 4c 89 02 49 89 50 08 48 c7 47 08 00 00 00 00 48 c7 07 00 All code ======== 0: 0f b7 50 12 movzwl 0x12(%rax),%edx 4: 48 8d 04 d5 00 00 00 lea 0x0(,%rdx,8),%rax b: 00 c: 48 89 d6 mov %rdx,%rsi f: 48 29 d0 sub %rdx,%rax 12: 48 8b 91 c0 01 00 00 mov 0x1c0(%rcx),%rdx 19: 48 c1 e0 03 shl $0x3,%rax 1d: 48 01 c2 add %rax,%rdx 20: 66 83 7a 1a 00 cmpw $0x0,0x1a(%rdx) 25: 7e c0 jle 0xffffffffffffffe7 27: 48 8b 3a mov (%rdx),%rdi 2a:* 4c 8b 07 mov (%rdi),%r8 <-- trapping instruction 2d: 4c 89 02 mov %r8,(%rdx) 30: 49 89 50 08 mov %rdx,0x8(%r8) 34: 48 c7 47 08 00 00 00 movq $0x0,0x8(%rdi) 3b: 00 3c: 48 rex.W 3d: c7 .byte 0xc7 3e: 07 (bad) ... Code starting with the faulting instruction =========================================== 0: 4c 8b 07 mov (%rdi),%r8 3: 4c 89 02 mov %r8,(%rdx) 6: 49 89 50 08 mov %rdx,0x8(%r8) a: 48 c7 47 08 00 00 00 movq $0x0,0x8(%rdi) 11: 00 12: 48 rex.W 13: c7 .byte 0xc7 14: 07 (bad) ... [ 88.803721] RSP: 0018:ffff9a1f892b7d58 EFLAGS: 00000206 [ 88.804032] RAX: 0000000000000000 RBX: ffff9a1f8420c800 RCX: ffff9a1f8420c800 [ 88.804560] RDX: ffff9a1f81bc1440 RSI: 0000000000000000 RDI: 0000000000000000 [ 88.805056] RBP: ffffffffc04bb0e0 R08: 0000000000000001 R09: 00000000ff7f9a1f [ 88.805473] R10: 000000000001001b R11: 0000000000009a1f R12: 0000000000000140 [ 88.806194] R13: 0000000000000001 R14: ffff9a1f886df400 R15: ffff9a1f886df4ac [ 88.806734] FS: 00007f445601a740(0000) GS:ffff9a2e7fd80000(0000) knlGS:0000000000000000 [ 88.807225] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 88.807672] CR2: 0000000000000000 CR3: 000000050cc46000 CR4: 00000000000006f0 [ 88.808165] Call Trace: [ 88.808459] <TASK> [ 88.808710] ? __die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434) [ 88.809261] ? page_fault_oops (arch/x86/mm/fault.c:715) [ 88.809561] ? exc_page_fault (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:87 ./arch/x86/include/asm/irqflags.h:147 arch/x86/mm/fault.c:1489 arch/x86/mm/fault.c:1539) [ 88.809806] ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:623) [ 88.810074] ? sfq_dequeue (net/sched/sch_sfq.c:272 net/sched/sch_sfq.c:499) sch_sfq [ 88.810411] sfq_reset (net/sched/sch_sfq.c:525) sch_sfq [ 88.810671] qdisc_reset (./include/linux/skbuff.h:2135 ./include/linux/skbuff.h:2441 ./include/linux/skbuff.h:3304 ./include/linux/skbuff.h:3310 net/sched/sch_generic.c:1036) [ 88.810950] tbf_reset (./include/linux/timekeeping.h:169 net/sched/sch_tbf.c:334) sch_tbf [ 88.811208] qdisc_reset (./include/linux/skbuff.h:2135 ./include/linux/skbuff.h:2441 ./include/linux/skbuff.h:3304 ./include/linux/skbuff.h:3310 net/sched/sch_generic.c:1036) [ 88.811484] netif_set_real_num_tx_queues (./include/linux/spinlock.h:396 ./include/net/sch_generic.h:768 net/core/dev.c:2958) [ 88.811870] __tun_detach (drivers/net/tun.c:590 drivers/net/tun.c:673) [ 88.812271] tun_chr_close (drivers/net/tun.c:702 drivers/net/tun.c:3517) [ 88.812505] __fput (fs/file_table.c:432 (discriminator 1)) [ 88.812735] task_work_run (kernel/task_work.c:230) [ 88.813016] do_exit (kernel/exit.c:940) [ 88.813372] ? trace_hardirqs_on (kernel/trace/trace_preemptirq.c:58 (discriminator 4)) [ 88.813639] ? handle_mm_fault (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:97 ./arch/x86/include/asm/irqflags.h:155 ./include/linux/memcontrol.h:1022 ./include/linux/memcontrol.h:1045 ./include/linux/memcontrol.h:1052 mm/memory.c:5928 mm/memory.c:6088) [ 88.813867] do_group_exit (kernel/exit.c:1070) [ 88.814138] __x64_sys_exit_group (kernel/exit.c:1099) [ 88.814490] x64_sys_call (??:?) [ 88.814791] do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) [ 88.815012] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) [ 88.815495] RIP: 0033:0x7f44560f1975 Fixes: 175f9c1b ("net_sched: Add size table for qdiscs") Reported-by:
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[ Upstream commit d5c45460 ] According to Vinicius (and carefully looking through the whole https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa once again), txtime branch of 'taprio_change()' is not going to race against 'advance_sched()'. But using 'rcu_replace_pointer()' in the former may be a good idea as well. Suggested-by:
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commit 546ea84d upstream. In sch_cake, we keep track of the count of active bulk flows per host, when running in dst/src host fairness mode, which is used as the round-robin weight when iterating through flows. The count of active bulk flows is updated whenever a flow changes state. This has a peculiar interaction with the hash collision handling: when a hash collision occurs (after the set-associative hashing), the state of the hash bucket is simply updated to match the new packet that collided, and if host fairness is enabled, that also means assigning new per-host state to the flow. For this reason, the bulk flow counters of the host(s) assigned to the flow are decremented, before new state is assigned (and the counters, which may not belong to the same host anymore, are incremented again). Back when this code was introduced, the host fairness mode was always enabled, so the decrement was unconditional. When the configuration flags were introduced the *increment* was made conditional, but the *decrement* was not. Which of course can lead to a spurious decrement (and associated wrap-around to U16_MAX). AFAICT, when host fairness is disabled, the decrement and wrap-around happens as soon as a hash collision occurs (which is not that common in itself, due to the set-associative hashing). However, in most cases this is harmless, as the value is only used when host fairness mode is enabled. So in order to trigger an array overflow, sch_cake has to first be configured with host fairness disabled, and while running in this mode, a hash collision has to occur to cause the overflow. Then, the qdisc has to be reconfigured to enable host fairness, which leads to the array out-of-bounds because the wrapped-around value is retained and used as an array index. It seems that syzbot managed to trigger this, which is quite impressive in its own right. This patch fixes the issue by introducing the same conditional check on decrement as is used on increment. The original bug predates the upstreaming of cake, but the commit listed in the Fixes tag touched that code, meaning that this patch won't apply before that. Fixes: 71263992 ("sch_cake: Make the dual modes fairer") Reported-by:
<syzbot+7fe7b81d602cc1e6b94d@syzkaller.appspotmail.com> Signed-off-by:
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commit 3b3a2a9c upstream. If netem_dequeue() enqueues packet to inner qdisc and that qdisc returns __NET_XMIT_STOLEN. The packet is dropped but qdisc_tree_reduce_backlog() is not called to update the parent's q.qlen, leading to the similar use-after-free as Commit e04991a48dbaf382 ("netem: fix return value if duplicate enqueue fails") Commands to trigger KASAN UaF: ip link add type dummy ip link set lo up ip link set dummy0 up tc qdisc add dev lo parent root handle 1: drr tc filter add dev lo parent 1: basic classid 1:1 tc class add dev lo classid 1:1 drr tc qdisc add dev lo parent 1:1 handle 2: netem tc qdisc add dev lo parent 2: handle 3: drr tc filter add dev lo parent 3: basic classid 3:1 action mirred egress redirect dev dummy0 tc class add dev lo classid 3:1 drr ping -c1 -W0.01 localhost # Trigger bug tc class del dev lo classid 1:1 tc class add dev lo classid 1:1 drr ping -c1 -W0.01 localhost # UaF Fixes: 50612537 ("netem: fix classful handling") Reported-by:
Stephen Hemminger <stephen@networkplumber.org> Link: https://patch.msgid.link/20240901182438.4992-1-stephen@networkplumber.org Signed-off-by:
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- Sep 17, 2024
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Stephen Hemminger authored
[ Upstream commit c07ff859 ] There is a bug in netem_enqueue() introduced by commit 5845f706 ("net: netem: fix skb length BUG_ON in __skb_to_sgvec") that can lead to a use-after-free. This commit made netem_enqueue() always return NET_XMIT_SUCCESS when a packet is duplicated, which can cause the parent qdisc's q.qlen to be mistakenly incremented. When this happens qlen_notify() may be skipped on the parent during destruction, leaving a dangling pointer for some classful qdiscs like DRR. There are two ways for the bug happen: - If the duplicated packet is dropped by rootq->enqueue() and then the original packet is also dropped. - If rootq->enqueue() sends the duplicated packet to a different qdisc and the original packet is dropped. In both cases NET_XMIT_SUCCESS is returned even though no packets are enqueued at the netem qdisc. The fix is to defer the enqueue of the duplicate packet until after the original packet has been guaranteed to return NET_XMIT_SUCCESS. Fixes: 5845f706 ("net: netem: fix skb length BUG_ON in __skb_to_sgvec") Reported-by:
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Jakub Kicinski authored
[ Upstream commit e316dd1c ] The top syzbot report for networking (#14 for the entire kernel) is the queue timeout splat. We kept it around for a long time, because in real life it provides pretty strong signal that something is wrong with the driver or the device. Removing it is also likely to break monitoring for those who track it as a kernel warning. Nevertheless, WARN()ings are best suited for catching kernel programming bugs. If a Tx queue gets starved due to a pause storm, priority configuration, or other weirdness - that's obviously a problem, but not a problem we can fix at the kernel level. Bite the bullet and convert the WARN() to a print. Before: NETDEV WATCHDOG: eni1np1 (netdevsim): transmit queue 0 timed out 1975 ms WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:525 dev_watchdog+0x39e/0x3b0 [... completely pointless stack trace of a timer follows ...] Now: netdevsim netdevsim1 eni1np1: NETDEV WATCHDOG: CPU: 0: transmit queue 0 timed out 1769 ms Alternatively we could mark the drivers which syzbot has learned to abuse as "print-instead-of-WARN" selectively. Reported-by:
<syzbot+d55372214aff0faa1f1f@syzkaller.appspotmail.com> Reviewed-by:
Jiri Pirko <jiri@nvidia.com> Reviewed-by:
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Yajun Deng authored
[ Upstream commit 2f0f9465 ] The kernel will print several warnings in a short period of time when it stalls. Like this: First warning: [ 7100.097547] ------------[ cut here ]------------ [ 7100.097550] NETDEV WATCHDOG: eno2 (xxx): transmit queue 8 timed out [ 7100.097571] WARNING: CPU: 8 PID: 0 at net/sched/sch_generic.c:467 dev_watchdog+0x260/0x270 ... Second warning: [ 7147.756952] rcu: INFO: rcu_preempt self-detected stall on CPU [ 7147.756958] rcu: 24-....: (59999 ticks this GP) idle=546/1/0x400000000000000 softirq=367 3137/3673146 fqs=13844 [ 7147.756960] (t=60001 jiffies g=4322709 q=133381) [ 7147.756962] NMI backtrace for cpu 24 ... We calculate that the transmit queue start stall should occur before 7095s according to watchdog_timeo, the rcu start stall at 7087s. These two times are close together, it is difficult to confirm which happened first. To let users know the exact time the stall started, print msecs when the transmit queue time out. Signed-off-by:
Yajun Deng <yajun.deng@linux.dev> Signed-off-by:
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Eric Dumazet authored
[ Upstream commit 2191a54f ] Blamed commit increased lookup key size from 2 bytes to 16 bytes, because zones_ht_key got a struct net pointer. Make sure rhashtable_lookup() is not using the padding bytes which are not initialized. BUG: KMSAN: uninit-value in rht_ptr_rcu include/linux/rhashtable.h:376 [inline] BUG: KMSAN: uninit-value in __rhashtable_lookup include/linux/rhashtable.h:607 [inline] BUG: KMSAN: uninit-value in rhashtable_lookup include/linux/rhashtable.h:646 [inline] BUG: KMSAN: uninit-value in rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline] BUG: KMSAN: uninit-value in tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329 rht_ptr_rcu include/linux/rhashtable.h:376 [inline] __rhashtable_lookup include/linux/rhashtable.h:607 [inline] rhashtable_lookup include/linux/rhashtable.h:646 [inline] rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline] tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329 tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408 tcf_action_init_1+0x6cc/0xb30 net/sched/act_api.c:1425 tcf_action_init+0x458/0xf00 net/sched/act_api.c:1488 tcf_action_add net/sched/act_api.c:2061 [inline] tc_ctl_action+0x4be/0x19d0 net/sched/act_api.c:2118 rtnetlink_rcv_msg+0x12fc/0x1410 net/core/rtnetlink.c:6647 netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2550 rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6665 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x30f/0x380 net/socket.c:745 ____sys_sendmsg+0x877/0xb60 net/socket.c:2597 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2651 __sys_sendmsg net/socket.c:2680 [inline] __do_sys_sendmsg net/socket.c:2689 [inline] __se_sys_sendmsg net/socket.c:2687 [inline] __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2687 x64_sys_call+0x2dd6/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Local variable key created at: tcf_ct_flow_table_get+0x4a/0x2260 net/sched/act_ct.c:324 tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408 Fixes: 88c67aeb ("sched: act_ct: add netns into the key of tcf_ct_flow_table") Reported-by:
<syzbot+1b5e4e187cc586d05ea0@syzkaller.appspotmail.com> Signed-off-by:
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- Aug 12, 2024
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[ Upstream commit 26488172 ] KASAN reports the following UAF: BUG: KASAN: slab-use-after-free in tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct] Read of size 1 at addr ffff888c07603600 by task handler130/6469 Call Trace: <IRQ> dump_stack_lvl+0x48/0x70 print_address_description.constprop.0+0x33/0x3d0 print_report+0xc0/0x2b0 kasan_report+0xd0/0x120 __asan_load1+0x6c/0x80 tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct] tcf_ct_act+0x886/0x1350 [act_ct] tcf_action_exec+0xf8/0x1f0 fl_classify+0x355/0x360 [cls_flower] __tcf_classify+0x1fd/0x330 tcf_classify+0x21c/0x3c0 sch_handle_ingress.constprop.0+0x2c5/0x500 __netif_receive_skb_core.constprop.0+0xb25/0x1510 __netif_receive_skb_list_core+0x220/0x4c0 netif_receive_skb_list_internal+0x446/0x620 napi_complete_done+0x157/0x3d0 gro_cell_poll+0xcf/0x100 __napi_poll+0x65/0x310 net_rx_action+0x30c/0x5c0 __do_softirq+0x14f/0x491 __irq_exit_rcu+0x82/0xc0 irq_exit_rcu+0xe/0x20 common_interrupt+0xa1/0xb0 </IRQ> <TASK> asm_common_interrupt+0x27/0x40 Allocated by task 6469: kasan_save_stack+0x38/0x70 kasan_set_track+0x25/0x40 kasan_save_alloc_info+0x1e/0x40 __kasan_krealloc+0x133/0x190 krealloc+0xaa/0x130 nf_ct_ext_add+0xed/0x230 [nf_conntrack] tcf_ct_act+0x1095/0x1350 [act_ct] tcf_action_exec+0xf8/0x1f0 fl_classify+0x355/0x360 [cls_flower] __tcf_classify+0x1fd/0x330 tcf_classify+0x21c/0x3c0 sch_handle_ingress.constprop.0+0x2c5/0x500 __netif_receive_skb_core.constprop.0+0xb25/0x1510 __netif_receive_skb_list_core+0x220/0x4c0 netif_receive_skb_list_internal+0x446/0x620 napi_complete_done+0x157/0x3d0 gro_cell_poll+0xcf/0x100 __napi_poll+0x65/0x310 net_rx_action+0x30c/0x5c0 __do_softirq+0x14f/0x491 Freed by task 6469: kasan_save_stack+0x38/0x70 kasan_set_track+0x25/0x40 kasan_save_free_info+0x2b/0x60 ____kasan_slab_free+0x180/0x1f0 __kasan_slab_free+0x12/0x30 slab_free_freelist_hook+0xd2/0x1a0 __kmem_cache_free+0x1a2/0x2f0 kfree+0x78/0x120 nf_conntrack_free+0x74/0x130 [nf_conntrack] nf_ct_destroy+0xb2/0x140 [nf_conntrack] __nf_ct_resolve_clash+0x529/0x5d0 [nf_conntrack] nf_ct_resolve_clash+0xf6/0x490 [nf_conntrack] __nf_conntrack_confirm+0x2c6/0x770 [nf_conntrack] tcf_ct_act+0x12ad/0x1350 [act_ct] tcf_action_exec+0xf8/0x1f0 fl_classify+0x355/0x360 [cls_flower] __tcf_classify+0x1fd/0x330 tcf_classify+0x21c/0x3c0 sch_handle_ingress.constprop.0+0x2c5/0x500 __netif_receive_skb_core.constprop.0+0xb25/0x1510 __netif_receive_skb_list_core+0x220/0x4c0 netif_receive_skb_list_internal+0x446/0x620 napi_complete_done+0x157/0x3d0 gro_cell_poll+0xcf/0x100 __napi_poll+0x65/0x310 net_rx_action+0x30c/0x5c0 __do_softirq+0x14f/0x491 The ct may be dropped if a clash has been resolved but is still passed to the tcf_ct_flow_table_process_conn function for further usage. This issue can be fixed by retrieving ct from skb again after confirming conntrack. Fixes: 0cc254e5 ("net/sched: act_ct: Offload connections with commit action") Co-developed-by:
Gerald Yang <gerald.yang@canonical.com> Signed-off-by:
Chengen Du <chengen.du@canonical.com> Link: https://patch.msgid.link/20240710053747.13223-1-chengen.du@canonical.com Signed-off-by:
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- Jul 11, 2024
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commit 86735b57 upstream. Naresh and Eric report several errors (corrupted elements in the dynamic key hash list), when running tdc.py or syzbot. The error path of qdisc_alloc() and qdisc_create() frees the qdisc memory, but it forgets to unregister the lockdep key, thus causing use-after-free like the following one: ================================================================== BUG: KASAN: slab-use-after-free in lockdep_register_key+0x5f2/0x700 Read of size 8 at addr ffff88811236f2a8 by task ip/7925 CPU: 26 PID: 7925 Comm: ip Kdump: loaded Not tainted 6.9.0-rc2+ #648 Hardware name: Supermicro SYS-6027R-72RF/X9DRH-7TF/7F/iTF/iF, BIOS 3.0 07/26/2013 Call Trace: <TASK> dump_stack_lvl+0x7c/0xc0 print_report+0xc9/0x610 kasan_report+0x89/0xc0 lockdep_register_key+0x5f2/0x700 qdisc_alloc+0x21d/0xb60 qdisc_create_dflt+0x63/0x3c0 attach_one_default_qdisc.constprop.37+0x8e/0x170 dev_activate+0x4bd/0xc30 __dev_open+0x275/0x380 __dev_change_flags+0x3f1/0x570 dev_change_flags+0x7c/0x160 do_setlink+0x1ea1/0x34b0 __rtnl_newlink+0x8c9/0x1510 rtnl_newlink+0x61/0x90 rtnetlink_rcv_msg+0x2f0/0xbc0 netlink_rcv_skb+0x120/0x380 netlink_unicast+0x420/0x630 netlink_sendmsg+0x732/0xbc0 __sock_sendmsg+0x1ea/0x280 ____sys_sendmsg+0x5a9/0x990 ___sys_sendmsg+0xf1/0x180 __sys_sendmsg+0xd3/0x180 do_syscall_64+0x96/0x180 entry_SYSCALL_64_after_hwframe+0x71/0x79 RIP: 0033:0x7f9503f4fa07 Code: 0a 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10 RSP: 002b:00007fff6c729068 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000006630c681 RCX: 00007f9503f4fa07 RDX: 0000000000000000 RSI: 00007fff6c7290d0 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000078 R10: 000000000000009b R11: 0000000000000246 R12: 0000000000000001 R13: 00007fff6c729180 R14: 0000000000000000 R15: 000055bf67dd9040 </TASK> Allocated by task 7745: kasan_save_stack+0x1c/0x40 kasan_save_track+0x10/0x30 __kasan_kmalloc+0x7b/0x90 __kmalloc_node+0x1ff/0x460 qdisc_alloc+0xae/0xb60 qdisc_create+0xdd/0xfb0 tc_modify_qdisc+0x37e/0x1960 rtnetlink_rcv_msg+0x2f0/0xbc0 netlink_rcv_skb+0x120/0x380 netlink_unicast+0x420/0x630 netlink_sendmsg+0x732/0xbc0 __sock_sendmsg+0x1ea/0x280 ____sys_sendmsg+0x5a9/0x990 ___sys_sendmsg+0xf1/0x180 __sys_sendmsg+0xd3/0x180 do_syscall_64+0x96/0x180 entry_SYSCALL_64_after_hwframe+0x71/0x79 Freed by task 7745: kasan_save_stack+0x1c/0x40 kasan_save_track+0x10/0x30 kasan_save_free_info+0x36/0x60 __kasan_slab_free+0xfe/0x180 kfree+0x113/0x380 qdisc_create+0xafb/0xfb0 tc_modify_qdisc+0x37e/0x1960 rtnetlink_rcv_msg+0x2f0/0xbc0 netlink_rcv_skb+0x120/0x380 netlink_unicast+0x420/0x630 netlink_sendmsg+0x732/0xbc0 __sock_sendmsg+0x1ea/0x280 ____sys_sendmsg+0x5a9/0x990 ___sys_sendmsg+0xf1/0x180 __sys_sendmsg+0xd3/0x180 do_syscall_64+0x96/0x180 entry_SYSCALL_64_after_hwframe+0x71/0x79 Fix this ensuring that lockdep_unregister_key() is called before the qdisc struct is freed, also in the error path of qdisc_create() and qdisc_alloc(). Fixes: af0cb3fa ("net/sched: fix false lockdep warning on qdisc root lock") Reported-by:
Linux Kernel Functional Testing <lkft@linaro.org> Closes: https://lore.kernel.org/netdev/20240429221706.1492418-1-naresh.kamboju@linaro.org/ Signed-off-by:
Davide Caratti <dcaratti@redhat.com> Reviewed-by:
Naresh Kamboju <naresh.kamboju@linaro.org> Tested-by:
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[ Upstream commit 88c67aeb ] zones_ht is a global hashtable for flow_table with zone as key. However, it does not consider netns when getting a flow_table from zones_ht in tcf_ct_init(), and it means an act_ct action in netns A may get a flow_table that belongs to netns B if it has the same zone value. In Shuang's test with the TOPO: tcf2_c <---> tcf2_sw1 <---> tcf2_sw2 <---> tcf2_s tcf2_sw1 and tcf2_sw2 saw the same flow and used the same flow table, which caused their ct entries entering unexpected states and the TCP connection not able to end normally. This patch fixes the issue simply by adding netns into the key of tcf_ct_flow_table so that an act_ct action gets a flow_table that belongs to its own netns in tcf_ct_init(). Note that for easy coding we don't use tcf_ct_flow_table.nf_ft.net, as the ct_ft is initialized after inserting it to the hashtable in tcf_ct_flow_table_get() and also it requires to implement several functions in rhashtable_params including hashfn, obj_hashfn and obj_cmpfn. Fixes: 64ff70b8 ("net/sched: act_ct: Offload established connections to flow table") Reported-by:
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[ Upstream commit d8643198 ] syzbot found hanging tasks waiting on rtnl_lock [1] A reproducer is available in the syzbot bug. When a request to add multiple actions with the same index is sent, the second request will block forever on the first request. This holds rtnl_lock, and causes tasks to hang. Return -EAGAIN to prevent infinite looping, while keeping documented behavior. [1] INFO: task kworker/1:0:5088 blocked for more than 143 seconds. Not tainted 6.9.0-rc4-syzkaller-00173-g3cdb45594619 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:0 state:D stack:23744 pid:5088 tgid:5088 ppid:2 flags:0x00004000 Workqueue: events_power_efficient reg_check_chans_work Call Trace: <TASK> context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6838 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 wiphy_lock include/net/cfg80211.h:5953 [inline] reg_leave_invalid_chans net/wireless/reg.c:2466 [inline] reg_check_chans_work+0x10a/0x10e0 net/wireless/reg.c:2481 Fixes: 0190c1d4 ("net: sched: atomically check-allocate action") Reported-by:
<syzbot+b87c222546179f4513a7@syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=b87c222546179f4513a7 Signed-off-by:
David Ruth <druth@chromium.org> Reviewed-by:
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[ Upstream commit 4b55e867 ] Instead of relying only on the idrinfo->lock mutex for bind/alloc logic, rely on a combination of rcu + mutex + atomics to better scale the case where multiple rtnl-less filters are binding to the same action object. Action binding happens when an action index is specified explicitly and an action exists which such index exists. Example: tc actions add action drop index 1 tc filter add ... matchall action drop index 1 tc filter add ... matchall action drop index 1 tc filter add ... matchall action drop index 1 tc filter ls ... filter protocol all pref 49150 matchall chain 0 filter protocol all pref 49150 matchall chain 0 handle 0x1 not_in_hw action order 1: gact action drop random type none pass val 0 index 1 ref 4 bind 3 filter protocol all pref 49151 matchall chain 0 filter protocol all pref 49151 matchall chain 0 handle 0x1 not_in_hw action order 1: gact action drop random type none pass val 0 index 1 ref 4 bind 3 filter protocol all pref 49152 matchall chain 0 filter protocol all pref 49152 matchall chain 0 handle 0x1 not_in_hw action order 1: gact action drop random type none pass val 0 index 1 ref 4 bind 3 When no index is specified, as before, grab the mutex and allocate in the idr the next available id. In this version, as opposed to before, it's simplified to store the -EBUSY pointer instead of the previous alloc + replace combination. When an index is specified, rely on rcu to find if there's an object in such index. If there's none, fallback to the above, serializing on the mutex and reserving the specified id. If there's one, it can be an -EBUSY pointer, in which case we just try again until it's an action, or an action. Given the rcu guarantees, the action found could be dead and therefore we need to bump the refcount if it's not 0, handling the case it's in fact 0. As bind and the action refcount are already atomics, these increments can happen without the mutex protection while many tcf_idr_check_alloc race to bind to the same action instance. In case binding encounters a parallel delete or add, it will return -EAGAIN in order to try again. Both filter and action apis already have the retry machinery in-place. In case it's an unlocked filter it retries under the rtnl lock. Signed-off-by:
Vlad Buslov <vladbu@nvidia.com> Link: https://lore.kernel.org/r/20231211181807.96028-2-pctammela@mojatatu.com Signed-off-by:
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[ Upstream commit af0cb3fa ] Xiumei and Christoph reported the following lockdep splat, complaining of the qdisc root lock being taken twice: ============================================ WARNING: possible recursive locking detected 6.7.0-rc3+ #598 Not tainted -------------------------------------------- swapper/2/0 is trying to acquire lock: ffff888177190110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 but task is already holding lock: ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&sch->q.lock); lock(&sch->q.lock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by swapper/2/0: #0: ffff888135a09d98 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x510 #1: ffffffffaaee5260 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x2c0/0x1ed0 #2: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70 #3: ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 #4: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70 stack backtrace: CPU: 2 PID: 0 Comm: swapper/2 Not tainted 6.7.0-rc3+ #598 Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x4a/0x80 __lock_acquire+0xfdd/0x3150 lock_acquire+0x1ca/0x540 _raw_spin_lock+0x34/0x80 __dev_queue_xmit+0x1560/0x2e70 tcf_mirred_act+0x82e/0x1260 [act_mirred] tcf_action_exec+0x161/0x480 tcf_classify+0x689/0x1170 prio_enqueue+0x316/0x660 [sch_prio] dev_qdisc_enqueue+0x46/0x220 __dev_queue_xmit+0x1615/0x2e70 ip_finish_output2+0x1218/0x1ed0 __ip_finish_output+0x8b3/0x1350 ip_output+0x163/0x4e0 igmp_ifc_timer_expire+0x44b/0x930 call_timer_fn+0x1a2/0x510 run_timer_softirq+0x54d/0x11a0 __do_softirq+0x1b3/0x88f irq_exit_rcu+0x18f/0x1e0 sysvec_apic_timer_interrupt+0x6f/0x90 </IRQ> This happens when TC does a mirred egress redirect from the root qdisc of device A to the root qdisc of device B. As long as these two locks aren't protecting the same qdisc, they can be acquired in chain: add a per-qdisc lockdep key to silence false warnings. This dynamic key should safely replace the static key we have in sch_htb: it was added to allow enqueueing to the device "direct qdisc" while still holding the qdisc root lock. v2: don't use static keys anymore in HTB direct qdiscs (thanks Eric Dumazet) CC: Maxim Mikityanskiy <maxim@isovalent.com> CC: Xiumei Mu <xmu@redhat.com> Reported-by:
Christoph Paasch <cpaasch@apple.com> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/451 Signed-off-by:
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[ Upstream commit f921a58a ] If one TCA_TAPRIO_ATTR_PRIOMAP attribute has been provided, taprio_parse_mqprio_opt() must validate it, or userspace can inject arbitrary data to the kernel, the second time taprio_change() is called. First call (with valid attributes) sets dev->num_tc to a non zero value. Second call (with arbitrary mqprio attributes) returns early from taprio_parse_mqprio_opt() and bad things can happen. Fixes: a3d43c0d ("taprio: Add support adding an admin schedule") Reported-by:
Noam Rathaus <noamr@ssd-disclosure.com> Signed-off-by:
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[ Upstream commit affc18fd ] q->bands will be assigned to qopt->bands to execute subsequent code logic after kmalloc. So the old q->bands should not be used in kmalloc. Otherwise, an out-of-bounds write will occur. Fixes: c2999f7f ("net: sched: multiq: don't call qdisc_put() while holding tree lock") Signed-off-by:
Hangyu Hua <hbh25y@gmail.com> Acked-by:
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- Apr 11, 2024
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commit 7eb32236 upstream. qdisc_tree_reduce_backlog() is called with the qdisc lock held, not RTNL. We must use qdisc_lookup_rcu() instead of qdisc_lookup() syzbot reported: WARNING: suspicious RCU usage 6.1.74-syzkaller #0 Not tainted ----------------------------- net/sched/sch_api.c:305 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by udevd/1142: #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline] #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: net_tx_action+0x64a/0x970 net/core/dev.c:5282 #1: ffff888171861108 (&sch->q.lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline] #1: ffff888171861108 (&sch->q.lock){+.-.}-{2:2}, at: net_tx_action+0x754/0x970 net/core/dev.c:5297 #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline] #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: qdisc_tree_reduce_backlog+0x84/0x580 net/sched/sch_api.c:792 stack backtrace: CPU: 1 PID: 1142 Comm: udevd Not tainted 6.1.74-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: <TASK> [<ffffffff85b85f14>] __dump_stack lib/dump_stack.c:88 [inline] [<ffffffff85b85f14>] dump_stack_lvl+0x1b1/0x28f lib/dump_stack.c:106 [<ffffffff85b86007>] dump_stack+0x15/0x1e lib/dump_stack.c:113 [<ffffffff81802299>] lockdep_rcu_suspicious+0x1b9/0x260 kernel/locking/lockdep.c:6592 [<ffffffff84f0054c>] qdisc_lookup+0xac/0x6f0 net/sched/sch_api.c:305 [<ffffffff84f037c3>] qdisc_tree_reduce_backlog+0x243/0x580 net/sched/sch_api.c:811 [<ffffffff84f5b78c>] pfifo_tail_enqueue+0x32c/0x4b0 net/sched/sch_fifo.c:51 [<ffffffff84fbcf63>] qdisc_enqueue include/net/sch_generic.h:833 [inline] [<ffffffff84fbcf63>] netem_dequeue+0xeb3/0x15d0 net/sched/sch_netem.c:723 [<ffffffff84eecab9>] dequeue_skb net/sched/sch_generic.c:292 [inline] [<ffffffff84eecab9>] qdisc_restart net/sched/sch_generic.c:397 [inline] [<ffffffff84eecab9>] __qdisc_run+0x249/0x1e60 net/sched/sch_generic.c:415 [<ffffffff84d7aa96>] qdisc_run+0xd6/0x260 include/net/pkt_sched.h:125 [<ffffffff84d85d29>] net_tx_action+0x7c9/0x970 net/core/dev.c:5313 [<ffffffff85e002bd>] __do_softirq+0x2bd/0x9bd kernel/softirq.c:616 [<ffffffff81568bca>] invoke_softirq kernel/softirq.c:447 [inline] [<ffffffff81568bca>] __irq_exit_rcu+0xca/0x230 kernel/softirq.c:700 [<ffffffff81568ae9>] irq_exit_rcu+0x9/0x20 kernel/softirq.c:712 [<ffffffff85b89f52>] sysvec_apic_timer_interrupt+0x42/0x90 arch/x86/kernel/apic/apic.c:1107 [<ffffffff85c00ccb>] asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:656 Fixes: d636fc5d ("net: sched: add rcu annotations around qdisc->qdisc_sleeping") Reported-by:
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