diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2019-03-13 07:56:02 -0400 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2019-04-01 16:11:11 -0400 |
| commit | 0d74e6a3b6421d98eeafbed26f29156d469bc0b5 (patch) | |
| tree | 13b9ab66fe1553126777b6afb114612743b6778c | |
| parent | 79a3aaa7b82e3106be97842dedfd8429248896e6 (diff) | |
dm integrity: change memcmp to strncmp in dm_integrity_ctr
If the string opt_string is small, the function memcmp can access bytes
that are beyond the terminating nul character. In theory, it could cause
segfault, if opt_string were located just below some unmapped memory.
Change from memcmp to strncmp so that we don't read bytes beyond the end
of the string.
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| -rw-r--r-- | drivers/md/dm-integrity.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index d57d997a52c8..33fac437569f 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -3185,7 +3185,7 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv) journal_watermark = val; else if (sscanf(opt_string, "commit_time:%u%c", &val, &dummy) == 1) sync_msec = val; - else if (!memcmp(opt_string, "meta_device:", strlen("meta_device:"))) { + else if (!strncmp(opt_string, "meta_device:", strlen("meta_device:"))) { if (ic->meta_dev) { dm_put_device(ti, ic->meta_dev); ic->meta_dev = NULL; @@ -3204,17 +3204,17 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv) goto bad; } ic->sectors_per_block = val >> SECTOR_SHIFT; - } else if (!memcmp(opt_string, "internal_hash:", strlen("internal_hash:"))) { + } else if (!strncmp(opt_string, "internal_hash:", strlen("internal_hash:"))) { r = get_alg_and_key(opt_string, &ic->internal_hash_alg, &ti->error, "Invalid internal_hash argument"); if (r) goto bad; - } else if (!memcmp(opt_string, "journal_crypt:", strlen("journal_crypt:"))) { + } else if (!strncmp(opt_string, "journal_crypt:", strlen("journal_crypt:"))) { r = get_alg_and_key(opt_string, &ic->journal_crypt_alg, &ti->error, "Invalid journal_crypt argument"); if (r) goto bad; - } else if (!memcmp(opt_string, "journal_mac:", strlen("journal_mac:"))) { + } else if (!strncmp(opt_string, "journal_mac:", strlen("journal_mac:"))) { r = get_alg_and_key(opt_string, &ic->journal_mac_alg, &ti->error, "Invalid journal_mac argument"); if (r) |