On 26/02/2021 09:29, Sean Nyekjaer wrote:

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.

Fixes: eabac19e40c0 ("squashfs: add more sanity checks in inode lookup") CC: stable@vger.kernel.org Signed-off-by: Sean Nyekjaer sean@geanix.com

Acked-by: phillip@squashfs.org.uk.

---

fs/squashfs/export.c | 8 ++++++-- fs/squashfs/squashfs_fs.h | 1 + 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/squashfs/export.c b/fs/squashfs/export.c index eb02072d28dd..723763746238 100644 --- a/fs/squashfs/export.c +++ b/fs/squashfs/export.c @@ -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); }

diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h index 8d64edb80ebf..b3fdc8212c5f 100644 --- a/fs/squashfs/squashfs_fs.h +++ b/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