CVE-2022-49220: dax: make sure inodes are flushed before destroy cache

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-02-26 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: dax: make sure inodes are flushed before destroy cache A bug can be triggered by following command $ modprobe nd_pmem && modprobe -r nd_pmem [ 10.060014] BUG dax_cache (Not tainted): Objects remaining in dax_cache on __kmem_cache_shutdown() [ 10.060938] Slab 0x0000000085b729ac objects=9 used=1 fp=0x000000004f5ae469 flags=0x200000000010200(slab|head|node) [ 10.062433] Call Trace: [ 10.062673] dump_stack_lvl+0x34/0x44 [ 10.062865] slab_err+0x90/0xd0 [ 10.063619] __kmem_cache_shutdown+0x13b/0x2f0 [ 10.063848] kmem_cache_destroy+0x4a/0x110 [ 10.064058] __x64_sys_delete_module+0x265/0x300 This is caused by dax_fs_exit() not flushing inodes before destroy cache. To fix this issue, call rcu_barrier() before destroy cache.

Affected products

Linux kernel: from 4.12 before 5.4.189; from 5.5 before 5.10.110; from 5.11 before 5.15.33; from 5.16 before 5.16.19; from 5.17 before 5.17.2 — fixed in 5.10.110, 5.15.33, 5.16.19, 5.17.2, 5.4.189

How to fix

Upgrade to a fixed version: Linux kernel 5.10.110, 5.15.33, 5.16.19, 5.17.2. Check the vendor advisory for mitigations.

References

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