UBUNTU-CVE-2025-68186
In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Do not warn in ring_buffer_map_get_reader() when reader catches up The function ring_buffer_map_get_reader() is a bit more strict than the other get reader functions, and except for certain situations the rb_get_reader_page() should not return NULL. If it does, it triggers a warning. This warning was triggering but after looking at why, it was because another acceptable situation was happening and it wasn't checked for. If the reader catches up to the writer and there's still data to be read on the reader page, then the rb_get_reader_page() will return NULL as there's no new page to get. In this situation, the reader page should not be updated and no warning should trigger.
02 / AFFECTED SOFTWARE
Affected packages
11 explicit affected versions
50 explicit affected versions
6 explicit affected versions
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19 explicit affected versions
10 explicit affected versions
6 explicit affected versions
24 explicit affected versions
10 explicit affected versions
26 explicit affected versions
7 explicit affected versions
13 explicit affected versions
35 explicit affected versions
18 explicit affected versions
13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
1 explicit affected versions
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16 explicit affected versions
10 explicit affected versions
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8 explicit affected versions
7 explicit affected versions
12 explicit affected versions
11 explicit affected versions
7 explicit affected versions
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10 explicit affected versions
1 explicit affected versions
7 explicit affected versions
12 explicit affected versions
1 explicit affected versions
12 explicit affected versions
16 explicit affected versions
9 explicit affected versions
10 explicit affected versions
37 explicit affected versions
1 explicit affected versions
13 explicit affected versions
3 explicit affected versions
10 explicit affected versions
11 explicit affected versions
26 explicit affected versions
13 explicit affected versions
29 explicit affected versions
13 explicit affected versions
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33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
11 explicit affected versions
5 explicit affected versions
12 explicit affected versions
1 explicit affected versions
7 explicit affected versions
12 explicit affected versions
8 explicit affected versions
5 explicit affected versions
10 explicit affected versions
26 explicit affected versions
11 explicit affected versions
1 explicit affected versions
13 explicit affected versions
16 explicit affected versions
3 explicit affected versions
7 explicit affected versions
7 explicit affected versions
51 explicit affected versions
8 explicit affected versions
18 explicit affected versions
12 explicit affected versions
1 explicit affected versions
27 explicit affected versions
8 explicit affected versions
5 explicit affected versions
8 explicit affected versions
10 explicit affected versions
7 explicit affected versions
13 explicit affected versions
13 explicit affected versions
7 explicit affected versions
8 explicit affected versions
10 explicit affected versions
12 explicit affected versions
9 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
9 explicit affected versions
11 explicit affected versions
6 explicit affected versions
7 explicit affected versions
4 explicit affected versions
1 explicit affected versions
13 explicit affected versions
43 explicit affected versions
6 explicit affected versions
10 explicit affected versions
8 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
6 explicit affected versions
11 explicit affected versions
1 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Do not warn in ring_buffer_map_get_reader() when reader catches up The function ring_buffer_map_get_reader() is a bit more strict than the other get reader functions, and except for certain situations the rb_get_reader_page() should not return NULL. If it does, it triggers a warning. This warning was triggering but after looking at why, it was because another acceptable situation was happening and it wasn't checked for. If the reader catches up to the writer and there's still data to be read on the reader page, then the rb_get_reader_page() will return NULL as there's no new page to get. In this situation, the reader page should not be updated and no warning should trigger.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/aa997d2d2a0b2e76f4df0f1f12829f02acb4fb6b
- https://git.kernel.org/stable/c/6f5c4f8109fa4d0955b3712597a26b310bdc736f
- https://git.kernel.org/stable/c/aa997d2d2a0b2e76f4df0f1f12829f02acb4fb6b
- https://git.kernel.org/stable/c/b42dbef4f208326271434d5ab71c4129a3ddd1a9
- https://ubuntu.com/security/CVE-2025-68186
- https://ubuntu.com/security/notices/USN-8029-1
- https://ubuntu.com/security/notices/USN-8029-2
- https://ubuntu.com/security/notices/USN-8029-3
- https://ubuntu.com/security/notices/USN-8030-1
- https://ubuntu.com/security/notices/USN-8048-1
- https://www.cve.org/CVERecord?id=CVE-2025-68186