CVE-2026-52933
io_uring/poll: fix signed comparison in io_poll_get_ownership()
In the Linux kernel, the following vulnerability has been resolved: io_uring/poll: fix signed comparison in io_poll_get_ownership() io_poll_get_ownership() uses a signed comparison to check whether poll_refs has reached the threshold for the slowpath: if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS)) atomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG (BIT(31)) is set in poll_refs, the value becomes negative in signed arithmetic, so the >= 128 comparison always evaluates to false and the slowpath is never taken. Fix this by casting the atomic_read() result to unsigned int before the comparison, so that the cancel flag is treated as a large positive value and correctly triggers the slowpath.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| Linux Linux |
≥ a26a35e9019fd70bf3cf647dcfdae87abc7bacea; < 81bf96b0abbfa4cd47ea32e12596aed3855fb2f3 (affected, git) ≥ a26a35e9019fd70bf3cf647dcfdae87abc7bacea; < cf522703d4f194991615763697ae25a3f9539763 (affected, git) ≥ a26a35e9019fd70bf3cf647dcfdae87abc7bacea; < fc47043f3d9af3efa407665b47f8378ec691ba18 (affected, git) ≥ a26a35e9019fd70bf3cf647dcfdae87abc7bacea; < ea0697129807d718037f618221037aa0660ee3c5 (affected, git) ≥ a26a35e9019fd70bf3cf647dcfdae87abc7bacea; < c6d191164dc81838d8dbf452a6000f68c558d1ae (affected, git) ≥ a26a35e9019fd70bf3cf647dcfdae87abc7bacea; < 326941b22806cbf2df1fbfe902b7908b368cce42 (affected, git) 4b702b7d11ce1b9d26fc6d7c5a7ef4ac1d455048 (affected, git) bc4e6ee16778149811333a969a7a893d4cc110c5 (affected, git) ≥ 5.15.82; < 5.16 (affected, semver) ≥ 6.0.11; < 6.1 (affected, semver) Other versions: unaffected |
CNA: Linux |
| Linux Linux |
6.1 (affected) ≥ 0; < 6.1 (unaffected, semver) ≥ 6.1.175; ≤ 6.1.* (unaffected, semver) ≥ 6.6.140; ≤ 6.6.* (unaffected, semver) ≥ 6.12.86; ≤ 6.12.* (unaffected, semver) ≥ 6.18.27; ≤ 6.18.* (unaffected, semver) ≥ 7.0.4; ≤ 7.0.* (unaffected, semver) ≥ 7.1; ≤ * (unaffected, original_commit_for_fix) Other versions: affected |
CNA: Linux |
| SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) Siemens |
≥ V3.1.6; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) Siemens |
≥ V3.1.7; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) Siemens |
≥ V3.1.6; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) Siemens |
≥ V3.1.7; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) Siemens |
≥ V3.1.6; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) Siemens |
≥ V3.1.7; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) Siemens |
≥ V3.1.6; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) Siemens |
≥ V3.1.7; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) Siemens |
≥ V3.1.6; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
| SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) Siemens |
≥ V3.1.7; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 7.8 high |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | CNA: Linux |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://git.kernel.org/stable/c/81bf96b0abbfa4cd47ea32e12596aed3855fb2f3CNA: Linux
- https://git.kernel.org/stable/c/cf522703d4f194991615763697ae25a3f9539763CNA: Linux
- https://git.kernel.org/stable/c/fc47043f3d9af3efa407665b47f8378ec691ba18CNA: Linux
- https://git.kernel.org/stable/c/ea0697129807d718037f618221037aa0660ee3c5CNA: Linux
- https://git.kernel.org/stable/c/c6d191164dc81838d8dbf452a6000f68c558d1aeCNA: Linux
- https://git.kernel.org/stable/c/326941b22806cbf2df1fbfe902b7908b368cce42CNA: Linux
- https://cert-portal.siemens.com/productcert/html/ssa-019113.htmlADP: siemens-SADP
- https://cert-portal.siemens.com/productcert/html/ssa-457936.htmlADP: siemens-SADP
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