squashfs: fix inode lookup sanity checks

When mouting a squashfs image created without inode compression it fails
with: "unable to read inode lookup table"

It turns out that the BLOCK_OFFSET is missing when checking the
SQUASHFS_METADATA_SIZE agaist the actual size.

Link: https://lkml.kernel.org/r/20210226092903.1473545-1-sean@geanix.com
Fixes: eabac19e40 ("squashfs: add more sanity checks in inode lookup")
Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Acked-by: Phillip Lougher <phillip@squashfs.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Sean Nyekjaer 2021-03-24 21:37:32 -07:00 committed by Linus Torvalds
parent 6d679578fe
commit c1b2028315
2 changed files with 7 additions and 2 deletions

View File

@ -152,14 +152,18 @@ __le64 *squashfs_read_inode_lookup_table(struct super_block *sb,
start = le64_to_cpu(table[n]);
end = le64_to_cpu(table[n + 1]);
if (start >= end || (end - start) > SQUASHFS_METADATA_SIZE) {
if (start >= end
|| (end - start) >
(SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) {
kfree(table);
return ERR_PTR(-EINVAL);
}
}
start = le64_to_cpu(table[indexes - 1]);
if (start >= lookup_table_start || (lookup_table_start - start) > SQUASHFS_METADATA_SIZE) {
if (start >= lookup_table_start ||
(lookup_table_start - start) >
(SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) {
kfree(table);
return ERR_PTR(-EINVAL);
}

View File

@ -17,6 +17,7 @@
/* size of metadata (inode and directory) blocks */
#define SQUASHFS_METADATA_SIZE 8192
#define SQUASHFS_BLOCK_OFFSET 2
/* default size of block device I/O */
#ifdef CONFIG_SQUASHFS_4K_DEVBLK_SIZE