From: Sean Nyekjaer sean@geanix.com Subject: 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: eabac19e40c0 ("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 ---
fs/squashfs/export.c | 8 ++++++-- fs/squashfs/squashfs_fs.h | 1 + 2 files changed, 7 insertions(+), 2 deletions(-)
--- a/fs/squashfs/export.c~squashfs-fix-inode-lookup-sanity-checks +++ a/fs/squashfs/export.c @@ -152,14 +152,18 @@ __le64 *squashfs_read_inode_lookup_table 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); } --- a/fs/squashfs/squashfs_fs.h~squashfs-fix-inode-lookup-sanity-checks +++ a/fs/squashfs/squashfs_fs.h @@ -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 _