Executive brief
A vulnerability exists in the Linux kernel's HFS file system driver, which is used to read and write older Apple-formatted disks. An attacker with local access to a system could exploit this flaw to cause a system crash or potentially access sensitive information from the computer's memory. This could lead to a loss of system availability or unauthorized data exposure.
Technical details
A slab-out-of-bounds access vulnerability exists in the Linux kernel HFS file system implementation within 'fs/hfs/bnode.c'. The issue stems from missing validation of offset and length parameters in functions such as hfs_bnode_read(), hfs_bnode_write(), hfs_bnode_clear(), hfs_bnode_copy(), and hfs_bnode_move(). A local attacker with low privileges can trigger these out-of-bounds accesses by providing specially crafted HFS filesystem structures. This can result in a kernel crash (DoS) or the leakage of sensitive kernel memory. The fix introduces 'is_bnode_offset_valid()' and 'check_and_correct_requested_length()' to enforce bounds checking on all bnode operations. Patches have been released for multiple stable kernel branches.
Affected products
- Linux Linux Kernel 2.6.12 to 6.13.y
- Siemens SIMATIC CN 4100 before V5.0
Timeline
- 2025-07-03: disclosed: Initial patch submitted by Viacheslav Dubeyko
- 2025-08-28: patched: Commits merged into stable kernel trees by Greg Kroah-Hartman
- 2025-09-04: advisory: CVE-2025-38715 published
References
- https://git.kernel.org/stable/c/384a66b89f9540a9a8cb0f48807697dfabaece4c
- https://git.kernel.org/stable/c/67ecc81f6492275c9c54280532f558483c99c90e
- https://git.kernel.org/stable/c/a1a60e79502279f996e55052f50cc14919020475
- https://git.kernel.org/stable/c/a431930c9bac518bf99d6b1da526a7f37ddee8d8
- https://git.kernel.org/stable/c/e7d2dc2421e821e4045775e6dc226378328de6f6
- https://git.kernel.org/stable/c/eec522fd0d28106b14a59ab2d658605febe4a3bb
- https://git.kernel.org/stable/c/efc095b35b23297e419c2ab4fc1ed1a8f0781a29