Bug 2532499 (CVE-2026-89499) - CVE-2026-89499 kernel: ring-buffer: Stop remote reader update when page swap fails
Summary: CVE-2026-89499 kernel: ring-buffer: Stop remote reader update when page swap ...
Keywords:
Status: NEW
Alias: CVE-2026-89499
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-11 23:29 UTC by OSIDB Bzimport
Modified: 2026-09-15 05:23 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
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Description OSIDB Bzimport 2026-09-11 23:29:27 UTC
In the Linux kernel, the following vulnerability has been resolved:

ring-buffer: Stop remote reader update when page swap fails

The remote swap_reader_page callback can return -EBUSY when the writer
moves the head before the remote catches it, particularly during an event
storm on a small buffer. __rb_get_reader_page_from_remote() currently
warns about that failure but continues with the unchanged reader ID and
rearranges the local page list as though the swap succeeded.

Handle the callback failure as a recoverable error. Report it with
pr_warn_ratelimited() and return NULL. Callers already handle a NULL reader
page as a failed attempt. This avoids splicing the same page as both the
previous and new reader without flooding the log under contention.


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