CVE-2023-53401

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

mm: kmem: fix a NULL pointer dereference in obj_stock_flush_required()

KCSAN found an issue in obj_stock_flush_required():

stock->cached_objcg can be reset between the check and dereference:

==================================================================

BUG: KCSAN: data-race in drain_all_stock / drain_obj_stock

write to 0xffff888237c2a2f8 of 8 bytes by task 19625 on cpu 0:

drain_obj_stock+0x408/0x4e0 mm/memcontrol.c:3306

refill_obj_stock+0x9c/0x1e0 mm/memcontrol.c:3340

obj_cgroup_uncharge+0xe/0x10 mm/memcontrol.c:3408

memcg_slab_free_hook mm/slab.h:587 [inline]

__cache_free mm/slab.c:3373 [inline]

__do_kmem_cache_free mm/slab.c:3577 [inline]

kmem_cache_free+0x105/0x280 mm/slab.c:3602

__d_free fs/dcache.c:298 [inline]

dentry_free fs/dcache.c:375 [inline]

__dentry_kill+0x422/0x4a0 fs/dcache.c:621

dentry_kill+0x8d/0x1e0

dput+0x118/0x1f0 fs/dcache.c:913

__fput+0x3bf/0x570 fs/file_table.c:329

____fput+

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References