From 3c0e013b9ffebc6d30c99e467e837cebfe4e6147 Mon Sep 17 00:00:00 2001
From: Michal Luczaj <mhal@rbox.co>
Date: Tue, 19 Nov 2024 14:31:41 +0100
Subject: [PATCH] llc: Improve setsockopt() handling of malformed user input
[ Upstream commit 1465036b10be4b8b00eb31c879e86de633ad74c1 ]
copy_from_sockptr() is used incorrectly: return value is the number of
bytes that could not be copied. Since it's deprecated, switch to
copy_safe_from_sockptr().
Note: Keeping the `optlen != sizeof(int)` check as copy_safe_from_sockptr()
by itself would also accept optlen > sizeof(int). Which would allow a more
lenient handling of inputs.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Suggested-by: David Wei <dw@davidwei.uk>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/llc/af_llc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index 4eb52add7103b..0259cde394ba0 100644
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -1098,7 +1098,7 @@ static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
lock_sock(sk);
if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
goto out;
- rc = copy_from_sockptr(&opt, optval, sizeof(opt));
+ rc = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen);
if (rc)
goto out;
rc = -EINVAL;
--
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