CVE-2024-26982
Assigner: Linux
Published: 2024-05-01T05:27:11.032Z
State: PUBLISHED
descriptions: value: In the Linux kernel, the following vulnerability has been resolved:

Squashfs: check the inode number is not the invalid value of zero

Syskiller has produced an out of bounds access in fill_meta_index().

That out of bounds access is ultimately caused because the inode
has an inode number with the invalid value of zero, which was not checked.

The reason this causes the out of bounds access is due to following
sequence of events:

1. Fill_meta_index() is called to allocate (via empty_meta_index())
   and fill a metadata index.  It however suffers a data read error
   and aborts, invalidating the newly returned empty metadata index.
   It does this by setting the inode number of the index to zero,
   which means unused (zero is not a valid inode number).

2. When fill_meta_index() is subsequently called again on another
   read operation, locate_meta_index() returns the previous index
   because it matches the inode number of 0.  Because this index
   has been returned it is expected to have been filled, and because
   it hasn't been, an out of bounds access is performed.

This patch adds a sanity check which checks that the inode number
is not zero when the inode is created and returns -EINVAL if it is.

[phillip@squashfs.org.uk: whitespace fix]
  Link: https://lkml.kernel.org/r/20240409204723.446925-1-phillip@squashfs.org.uk
affected: product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions: version: 1da177e4c3f4
lessThan: be383effaee3
status: affected
versionType: git
version: 1da177e4c3f4
lessThan: 7def00ebc9f2
status: affected
versionType: git
version: 1da177e4c3f4
lessThan: 9253c54e01b6
status: affected
versionType: git
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions: version: 6.6.30
lessThanOrEqual: 6.6.*
status: unaffected
versionType: custom
version: 6.8.8
lessThanOrEqual: 6.8.*
status: unaffected
versionType: custom
version: 6.9
lessThanOrEqual: *
status: unaffected
versionType: original_commit_for_fix
title: Squashfs: check the inode number is not the invalid value of zero
x_generator: engine: bippy-d175d3acf727