CVE-2026-99158
ring-buffer: Fix false warning in ring_buffer_map_get_reader()
Description
In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix false warning in ring_buffer_map_get_reader() The mmap reader can warn when it catches up with a writer that is still committing events. rb_get_reader_page() returns NULL in this case, but ring_buffer_map_get_reader() treats that result as an error. The initial rb_per_cpu_empty() check filters out an empty buffer, but it does not guarantee that the next reader page has committed data. Writers do not take reader_lock and can advance commit_page before publishing the committed length on the new page. rb_get_reader_page() can swap to that page, catch up with the writer and return NULL. Handle NULL through the existing no-data exit without warning. Remove the caller's reader_page == commit_page check as well, since the reader-page helper already handles that case. The existing metadata update and return path remain in place.
INFO
Published Date :
Oct. 28, 2026, 11:17 a.m.
Last Modified :
Oct. 28, 2026, 11:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Handle NULL return from rb_get_reader_page() gracefully.
- Remove unnecessary reader_page == commit_page check.
- Ensure metadata updates and return paths are maintained.
References to Advisories, Solutions, and Tools
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CVE-2026-99158.
CWE - Common Weakness Enumeration
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specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-99158 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-99158
weaknesses.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Oct. 28, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix false warning in ring_buffer_map_get_reader() The mmap reader can warn when it catches up with a writer that is still committing events. rb_get_reader_page() returns NULL in this case, but ring_buffer_map_get_reader() treats that result as an error. The initial rb_per_cpu_empty() check filters out an empty buffer, but it does not guarantee that the next reader page has committed data. Writers do not take reader_lock and can advance commit_page before publishing the committed length on the new page. rb_get_reader_page() can swap to that page, catch up with the writer and return NULL. Handle NULL through the existing no-data exit without warning. Remove the caller's reader_page == commit_page check as well, since the reader-page helper already handles that case. The existing metadata update and return path remain in place. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/99xxx/CVE-2026-99158.json">CVE-2026-99158</a> Added Reference https://git.kernel.org/stable/c/029770f5badedc0f0ff85fc45e24785cbbee4a67 Added Reference https://git.kernel.org/stable/c/68e6ab180cfb6dfa79652f41ed7899a6d4cf5438 Added Reference https://git.kernel.org/stable/c/89bab1dba8a0167ef0d819e0f55b6bafa038e87f