Bug 2348899 (CVE-2025-21817)

Summary: CVE-2025-21817 kernel: block: mark GFP_NOIO around sysfs ->store()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-02-27 21:02:28 UTC 
In the Linux kernel, the following vulnerability has been resolved:

block: mark GFP_NOIO around sysfs ->store()

sysfs ->store is called with queue freezed, meantime we have several
->store() callbacks(update_nr_requests, wbt, scheduler) to allocate
memory with GFP_KERNEL which may run into direct reclaim code path,
then potential deadlock can be caused.

Fix the issue by marking NOIO around sysfs ->store()
Comment 1 Avinash Hanwate 2025-02-28 05:40:04 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022710-CVE-2025-21817-2fc8@gregkh/T