Bug 2365033 (CVE-2025-37804)

Summary: CVE-2025-37804 kernel: io_uring: always do atomic put from iowq
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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[REJECTED CVE] In the Linux kernel, the following vulnerability has been resolved: io_uring: always do atomic put from iowq
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Description OSIDB Bzimport 2025-05-08 07:02:30 UTC 
In the Linux kernel, the following vulnerability has been resolved:

io_uring: always do atomic put from iowq

io_uring always switches requests to atomic refcounting for iowq
execution before there is any parallilism by setting REQ_F_REFCOUNT,
and the flag is not cleared until the request completes. That should be
fine as long as the compiler doesn't make up a non existing value for
the flags, however KCSAN still complains when the request owner changes
oter flag bits:

BUG: KCSAN: data-race in io_req_task_cancel / io_wq_free_work
...
read to 0xffff888117207448 of 8 bytes by task 3871 on cpu 0:
 req_ref_put_and_test io_uring/refs.h:22 [inline]

Skip REQ_F_REFCOUNT checks for iowq, we know it's set.
Comment 1 Avinash Hanwate 2025-05-08 10:06:25 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025050814-CVE-2025-37804-9c2b@gregkh/T
Comment 2 TEJ RATHI 2025-05-29 06:39:46 UTC 
This CVE has been rejected by the Linux kernel community. Refer to the announcement: https://lore.kernel.org/linux-cve-announce/2025052019-REJECTED-02e4@gregkh/

Comment added by: Automated Script