Bug 2348260 (CVE-2022-49220)

Summary:	CVE-2022-49220 kernel: dax: make sure inodes are flushed before destroy cache
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	dfreiber, drow, jburrell, vkumar
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2025-02-26 03:23:12 UTC

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.

Comment 1 Avinash Hanwate 2025-02-26 13:11:26 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022621-CVE-2022-49220-7247@gregkh/T

Comment 4 Avinash Hanwate 2025-02-26 17:24:43 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022621-CVE-2022-49220-7247@gregkh/T