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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-07-29 21:44:46 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-07-29 21:44:46 +0200 |
| commit | 01cfb7937a9af2abb1136c7e89fbf3fd92952956 (patch) | |
| tree | 2b01fbc7eb315150d5a0ed71a218e4008801138b /fs/squashfs/cache.c | |
| parent | Merge tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/ker... (diff) | |
| download | linux-01cfb7937a9af2abb1136c7e89fbf3fd92952956.tar.xz linux-01cfb7937a9af2abb1136c7e89fbf3fd92952956.zip | |
squashfs: be more careful about metadata corruption
Anatoly Trosinenko reports that a corrupted squashfs image can cause a
kernel oops. It turns out that squashfs can end up being confused about
negative fragment lengths.
The regular squashfs_read_data() does check for negative lengths, but
squashfs_read_metadata() did not, and the fragment size code just
blindly trusted the on-disk value. Fix both the fragment parsing and
the metadata reading code.
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/squashfs/cache.c')
| -rw-r--r-- | fs/squashfs/cache.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/squashfs/cache.c b/fs/squashfs/cache.c index 23813c078cc9..0839efa720b3 100644 --- a/fs/squashfs/cache.c +++ b/fs/squashfs/cache.c @@ -350,6 +350,9 @@ int squashfs_read_metadata(struct super_block *sb, void *buffer, TRACE("Entered squashfs_read_metadata [%llx:%x]\n", *block, *offset); + if (unlikely(length < 0)) + return -EIO; + while (length) { entry = squashfs_cache_get(sb, msblk->block_cache, *block, 0); if (entry->error) { |