Bug 2393519 (CVE-2025-39698)

Summary: CVE-2025-39698 kernel: io_uring/futex: ensure io_futex_wait() cleans up properly on failure
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedKeywords: Security
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2025-09-05 18:03:55 UTC 
In the Linux kernel, the following vulnerability has been resolved:

io_uring/futex: ensure io_futex_wait() cleans up properly on failure

The io_futex_data is allocated upfront and assigned to the io_kiocb
async_data field, but the request isn't marked with REQ_F_ASYNC_DATA
at that point. Those two should always go together, as the flag tells
io_uring whether the field is valid or not.

Additionally, on failure cleanup, the futex handler frees the data but
does not clear ->async_data. Clear the data and the flag in the error
path as well.

Thanks to Trend Micro Zero Day Initiative and particularly ReDress for
reporting this.
Comment 1 Jon Moroney 2025-09-05 21:17:00 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025090548-CVE-2025-39698-41e0@gregkh/T
Comment 5 errata-xmlrpc 2025-09-29 05:05:44 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2025:16880 https://access.redhat.com/errata/RHSA-2025:16880
Comment 6 errata-xmlrpc 2025-09-29 07:48:01 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2025:16904 https://access.redhat.com/errata/RHSA-2025:16904