diff options
| author | Fedor Pchelkin <pchelkin@ispras.ru> | 2023-01-17 13:52:26 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-01-31 16:44:08 -0800 |
| commit | 72e544b1b28325fe78a4687b980871a7e4101f76 (patch) | |
| tree | 9962f7fdd3d5c3ec02f968ce2103f085a97af802 | |
| parent | 6f28a2613497fc587e347afa99fa2c52230678a7 (diff) | |
squashfs: harden sanity check in squashfs_read_xattr_id_table
While mounting a corrupted filesystem, a signed integer '*xattr_ids' can
become less than zero. This leads to the incorrect computation of 'len'
and 'indexes' values which can cause null-ptr-deref in copy_bio_to_actor()
or out-of-bounds accesses in the next sanity checks inside
squashfs_read_xattr_id_table().
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Link: https://lkml.kernel.org/r/20230117105226.329303-2-pchelkin@ispras.ru
Fixes: 506220d2ba21 ("squashfs: add more sanity checks in xattr id lookup")
Reported-by: <syzbot+082fa4af80a5bb1a9843@syzkaller.appspotmail.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | fs/squashfs/xattr_id.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/squashfs/xattr_id.c b/fs/squashfs/xattr_id.c index 087cab8c78f4..f6d78cbc3e74 100644 --- a/fs/squashfs/xattr_id.c +++ b/fs/squashfs/xattr_id.c @@ -76,7 +76,7 @@ __le64 *squashfs_read_xattr_id_table(struct super_block *sb, u64 table_start, /* Sanity check values */ /* there is always at least one xattr id */ - if (*xattr_ids == 0) + if (*xattr_ids <= 0) return ERR_PTR(-EINVAL); len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids); |