squashfs: more metadata hardening

Anatoly reports another squashfs fuzzing issue, where the decompression
parameters themselves are in a compressed block.

This causes squashfs_read_data() to be called in order to read the
decompression options before the decompression stream having been set
up, making squashfs go sideways.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Acked-by: Phillip Lougher <phillip.lougher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2018-07-30 14:27:15 -07:00
parent 527838d470
commit d512584780

View file

@ -167,6 +167,8 @@ int squashfs_read_data(struct super_block *sb, u64 index, int length,
}
if (compressed) {
if (!msblk->stream)
goto read_failure;
length = squashfs_decompress(msblk, bh, b, offset, length,
output);
if (length < 0)