diff --git a/block/partitions/amiga.c b/block/partitions/amiga.c
index 85c5c79aae4819e9dceefe6a014241248594ff0a..ed222b9c901bbfae96b252cceb08a38505f062a4 100644
--- a/block/partitions/amiga.c
+++ b/block/partitions/amiga.c
@@ -11,10 +11,18 @@
#define pr_fmt(fmt) fmt
#include <linux/types.h>
+#include <linux/mm_types.h>
+#include <linux/overflow.h>
#include <linux/affs_hardblocks.h>
#include "check.h"
+/* magic offsets in partition DosEnvVec */
+#define NR_HD 3
+#define NR_SECT 5
+#define LO_CYL 9
+#define HI_CYL 10
+
static __inline__ u32
checksum_block(__be32 *m, int size)
{
@@ -31,9 +39,12 @@ int amiga_partition(struct parsed_partitions *state)
unsigned char *data;
struct RigidDiskBlock *rdb;
struct PartitionBlock *pb;
- sector_t start_sect, nr_sects;
- int blk, part, res = 0;
- int blksize = 1; /* Multiplier for disk block size */
+ u64 start_sect, nr_sects;
+ sector_t blk, end_sect;
+ u32 cylblk; /* rdb_CylBlocks = nr_heads*sect_per_track */
+ u32 nr_hd, nr_sect, lo_cyl, hi_cyl;
+ int part, res = 0;
+ unsigned int blksize = 1; /* Multiplier for disk block size */
int slot = 1;
for (blk = 0; ; blk++, put_dev_sector(sect)) {
@@ -41,7 +52,7 @@ int amiga_partition(struct parsed_partitions *state)
goto rdb_done;
data = read_part_sector(state, blk, §);
if (!data) {
- pr_err("Dev %s: unable to read RDB block %d\n",
+ pr_err("Dev %s: unable to read RDB block %llu\n",
state->disk->disk_name, blk);
res = -1;
goto rdb_done;
@@ -58,12 +69,12 @@ int amiga_partition(struct parsed_partitions *state)
*(__be32 *)(data+0xdc) = 0;
if (checksum_block((__be32 *)data,
be32_to_cpu(rdb->rdb_SummedLongs) & 0x7F)==0) {
- pr_err("Trashed word at 0xd0 in block %d ignored in checksum calculation\n",
+ pr_err("Trashed word at 0xd0 in block %llu ignored in checksum calculation\n",
blk);
break;
}
- pr_err("Dev %s: RDB in block %d has bad checksum\n",
+ pr_err("Dev %s: RDB in block %llu has bad checksum\n",
state->disk->disk_name, blk);
}
@@ -80,10 +91,15 @@ int amiga_partition(struct parsed_partitions *state)
blk = be32_to_cpu(rdb->rdb_PartitionList);
put_dev_sector(sect);
for (part = 1; blk>0 && part<=16; part++, put_dev_sector(sect)) {
- blk *= blksize; /* Read in terms partition table understands */
+ /* Read in terms partition table understands */
+ if (check_mul_overflow(blk, (sector_t) blksize, &blk)) {
+ pr_err("Dev %s: overflow calculating partition block %llu! Skipping partitions %u and beyond\n",
+ state->disk->disk_name, blk, part);
+ break;
+ }
data = read_part_sector(state, blk, §);
if (!data) {
- pr_err("Dev %s: unable to read partition block %d\n",
+ pr_err("Dev %s: unable to read partition block %llu\n",
state->disk->disk_name, blk);
res = -1;
goto rdb_done;
@@ -95,19 +111,70 @@ int amiga_partition(struct parsed_partitions *state)
if (checksum_block((__be32 *)pb, be32_to_cpu(pb->pb_SummedLongs) & 0x7F) != 0 )
continue;
- /* Tell Kernel about it */
+ /* RDB gives us more than enough rope to hang ourselves with,
+ * many times over (2^128 bytes if all fields max out).
+ * Some careful checks are in order, so check for potential
+ * overflows.
+ * We are multiplying four 32 bit numbers to one sector_t!
+ */
+
+ nr_hd = be32_to_cpu(pb->pb_Environment[NR_HD]);
+ nr_sect = be32_to_cpu(pb->pb_Environment[NR_SECT]);
+
+ /* CylBlocks is total number of blocks per cylinder */
+ if (check_mul_overflow(nr_hd, nr_sect, &cylblk)) {
+ pr_err("Dev %s: heads*sects %u overflows u32, skipping partition!\n",
+ state->disk->disk_name, cylblk);
+ continue;
+ }
+
+ /* check for consistency with RDB defined CylBlocks */
+ if (cylblk > be32_to_cpu(rdb->rdb_CylBlocks)) {
+ pr_warn("Dev %s: cylblk %u > rdb_CylBlocks %u!\n",
+ state->disk->disk_name, cylblk,
+ be32_to_cpu(rdb->rdb_CylBlocks));
+ }
+
+ /* RDB allows for variable logical block size -
+ * normalize to 512 byte blocks and check result.
+ */
+
+ if (check_mul_overflow(cylblk, blksize, &cylblk)) {
+ pr_err("Dev %s: partition %u bytes per cyl. overflows u32, skipping partition!\n",
+ state->disk->disk_name, part);
+ continue;
+ }
+
+ /* Calculate partition start and end. Limit of 32 bit on cylblk
+ * guarantees no overflow occurs if LBD support is enabled.
+ */
+
+ lo_cyl = be32_to_cpu(pb->pb_Environment[LO_CYL]);
+ start_sect = ((u64) lo_cyl * cylblk);
+
+ hi_cyl = be32_to_cpu(pb->pb_Environment[HI_CYL]);
+ nr_sects = (((u64) hi_cyl - lo_cyl + 1) * cylblk);
- nr_sects = ((sector_t)be32_to_cpu(pb->pb_Environment[10]) + 1 -
- be32_to_cpu(pb->pb_Environment[9])) *
- be32_to_cpu(pb->pb_Environment[3]) *
- be32_to_cpu(pb->pb_Environment[5]) *
- blksize;
if (!nr_sects)
continue;
- start_sect = (sector_t)be32_to_cpu(pb->pb_Environment[9]) *
- be32_to_cpu(pb->pb_Environment[3]) *
- be32_to_cpu(pb->pb_Environment[5]) *
- blksize;
+
+ /* Warn user if partition end overflows u32 (AmigaDOS limit) */
+
+ if ((start_sect + nr_sects) > UINT_MAX) {
+ pr_warn("Dev %s: partition %u (%llu-%llu) needs 64 bit device support!\n",
+ state->disk->disk_name, part,
+ start_sect, start_sect + nr_sects);
+ }
+
+ if (check_add_overflow(start_sect, nr_sects, &end_sect)) {
+ pr_err("Dev %s: partition %u (%llu-%llu) needs LBD device support, skipping partition!\n",
+ state->disk->disk_name, part,
+ start_sect, end_sect);
+ continue;
+ }
+
+ /* Tell Kernel about it */
+
put_partition(state,slot++,start_sect,nr_sects);
{
/* Be even more informative to aid mounting */