UBUNTU-CVE-2026-53319
In the Linux kernel, the following vulnerability has been resolved: blk-wbt: remove WARN_ON_ONCE from wbt_init_enable_default() wbt_init_enable_default() uses WARN_ON_ONCE to check for failures from wbt_alloc() and wbt_init(). However, both are expected failure paths: - wbt_alloc() can return NULL under memory pressure (-ENOMEM) - wbt_init() can fail with -EBUSY if wbt is already registered syzbot triggers this by injecting memory allocation failures during MTD partition creation via ioctl(BLKPG), causing a spurious warning. wbt_init_enable_default() is a best-effort initialization called from blk_register_queue() with a void return type. Failure simply means the disk operates without writeback throttling, which is harmless. Replace WARN_ON_ONCE with plain if-checks, consistent with how wbt_set_lat() in the same file already handles these failures. Add a pr_warn() for the wbt_init() failure to retain diagnostic information without triggering a full stack trace.
02 / AFFECTED SOFTWARE
Affected packages
12 explicit affected versions
19 explicit affected versions
10 explicit affected versions
6 explicit affected versions
24 explicit affected versions
2 explicit affected versions
10 explicit affected versions
26 explicit affected versions
7 explicit affected versions
13 explicit affected versions
35 explicit affected versions
1 explicit affected versions
18 explicit affected versions
1 explicit affected versions
13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
1 explicit affected versions
21 explicit affected versions
16 explicit affected versions
10 explicit affected versions
7 explicit affected versions
8 explicit affected versions
7 explicit affected versions
12 explicit affected versions
11 explicit affected versions
7 explicit affected versions
12 explicit affected versions
14 explicit affected versions
1 explicit affected versions
7 explicit affected versions
12 explicit affected versions
12 explicit affected versions
9 explicit affected versions
9 explicit affected versions
16 explicit affected versions
6 explicit affected versions
10 explicit affected versions
37 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
12 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
11 explicit affected versions
5 explicit affected versions
12 explicit affected versions
7 explicit affected versions
12 explicit affected versions
17 explicit affected versions
5 explicit affected versions
10 explicit affected versions
26 explicit affected versions
11 explicit affected versions
13 explicit affected versions
16 explicit affected versions
10 explicit affected versions
3 explicit affected versions
7 explicit affected versions
51 explicit affected versions
18 explicit affected versions
12 explicit affected versions
27 explicit affected versions
3 explicit affected versions
8 explicit affected versions
8 explicit affected versions
3 explicit affected versions
5 explicit affected versions
8 explicit affected versions
6 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
11 explicit affected versions
7 explicit affected versions
4 explicit affected versions
1 explicit affected versions
7 explicit affected versions
13 explicit affected versions
43 explicit affected versions
10 explicit affected versions
8 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
11 explicit affected versions
1 explicit affected versions
6 explicit affected versions
11 explicit affected versions
4 explicit affected versions
50 explicit affected versions
6 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: blk-wbt: remove WARN_ON_ONCE from wbt_init_enable_default() wbt_init_enable_default() uses WARN_ON_ONCE to check for failures from wbt_alloc() and wbt_init(). However, both are expected failure paths: - wbt_alloc() can return NULL under memory pressure (-ENOMEM) - wbt_init() can fail with -EBUSY if wbt is already registered syzbot triggers this by injecting memory allocation failures during MTD partition creation via ioctl(BLKPG), causing a spurious warning. wbt_init_enable_default() is a best-effort initialization called from blk_register_queue() with a void return type. Failure simply means the disk operates without writeback throttling, which is harmless. Replace WARN_ON_ONCE with plain if-checks, consistent with how wbt_set_lat() in the same file already handles these failures. Add a pr_warn() for the wbt_init() failure to retain diagnostic information without triggering a full stack trace.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/e9b004ff83067cdf96774b45aea4b239ace99a2f
- https://git.kernel.org/stable/c/e9b004ff83067cdf96774b45aea4b239ace99a2f
- https://git.kernel.org/stable/c/fd7a982657077469802594a5165bc30b9a55af70
- https://ubuntu.com/security/CVE-2026-53319
- https://ubuntu.com/security/notices/USN-8566-1
- https://ubuntu.com/security/notices/USN-8568-1
- https://ubuntu.com/security/notices/USN-8569-1
- https://ubuntu.com/security/notices/USN-8593-1
- https://ubuntu.com/security/notices/USN-8603-1
- https://ubuntu.com/security/notices/USN-8618-1
- https://www.cve.org/CVERecord?id=CVE-2026-53319