CVE-2026-53239
xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()
In the Linux kernel, the following vulnerability has been resolved: xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx() Fix the race by pruning the bin while still holding xfrm_policy_lock, before dropping it. Use __xfrm_policy_inexact_prune_bin() directly since the lock is already held. The wrapper xfrm_policy_inexact_prune_bin() becomes unused and is removed. Race: CPU0 (XFRM_MSG_DELPOLICY) CPU1 (XFRM_MSG_NEWSPDINFO) ========================== ========================== xfrm_policy_bysel_ctx(): spin_lock_bh(xfrm_policy_lock) bin = xfrm_policy_inexact_lookup() __xfrm_policy_unlink(pol) spin_unlock_bh(xfrm_policy_lock) xfrm_policy_kill(ret) // wide window, lock not held xfrm_hash_rebuild(): spin_lock_bh(xfrm_policy_lock) __xfrm_policy_inexact_flush(): kfree_rcu(bin) // bin freed spin_unlock_bh(xfrm_policy_lock) xfrm_policy_inexact_prune_bin(bin) // UAF: bin is freed
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 |
≥ 6be3b0db6db82cf056a72cc18042048edd27f8ee; < 8fc536e9f6856230f19c7d13e71af064b6a77b22 (affected, git) ≥ 6be3b0db6db82cf056a72cc18042048edd27f8ee; < c4c1ea36d83bf3c4569468ca5b8b614fda1bf821 (affected, git) ≥ 6be3b0db6db82cf056a72cc18042048edd27f8ee; < 25c8c7fb3b0b9668c7d05e209f58c158d2b020c7 (affected, git) ≥ 6be3b0db6db82cf056a72cc18042048edd27f8ee; < 42827d03f8009a6a218bacab153e21f39d6a121c (affected, git) ≥ 6be3b0db6db82cf056a72cc18042048edd27f8ee; < 88697cf980222d5906a37bf47662dac0732e2a0f (affected, git) ≥ 6be3b0db6db82cf056a72cc18042048edd27f8ee; < b5316e2b8614a87d8736941972441cb47bfd4491 (affected, git) ≥ 6be3b0db6db82cf056a72cc18042048edd27f8ee; < ec82ea4eb220164d854f8734ca5a35e23e577b94 (affected, git) ≥ 6be3b0db6db82cf056a72cc18042048edd27f8ee; < 7f2d76c9c03257c0782afef9d95321fa04096f60 (affected, git) Other versions: unaffected |
CNA: Linux |
| Linux Linux |
5.0 (affected) ≥ 0; < 5.0 (unaffected, semver) ≥ 5.10.259; ≤ 5.10.* (unaffected, semver) ≥ 5.15.210; ≤ 5.15.* (unaffected, semver) ≥ 6.1.176; ≤ 6.1.* (unaffected, semver) ≥ 6.6.143; ≤ 6.6.* (unaffected, semver) ≥ 6.12.94; ≤ 6.12.* (unaffected, semver) ≥ 6.18.36; ≤ 6.18.* (unaffected, semver) ≥ 7.0.13; ≤ 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 |
| SIMATIC S7-1500 TM MFP - GNU/Linux subsystem Siemens |
≥ 0; < * (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/8fc536e9f6856230f19c7d13e71af064b6a77b22CNA: Linux
- https://git.kernel.org/stable/c/c4c1ea36d83bf3c4569468ca5b8b614fda1bf821CNA: Linux
- https://git.kernel.org/stable/c/25c8c7fb3b0b9668c7d05e209f58c158d2b020c7CNA: Linux
- https://git.kernel.org/stable/c/42827d03f8009a6a218bacab153e21f39d6a121cCNA: Linux
- https://git.kernel.org/stable/c/88697cf980222d5906a37bf47662dac0732e2a0fCNA: Linux
- https://git.kernel.org/stable/c/b5316e2b8614a87d8736941972441cb47bfd4491CNA: Linux
- https://git.kernel.org/stable/c/ec82ea4eb220164d854f8734ca5a35e23e577b94CNA: Linux
- https://git.kernel.org/stable/c/7f2d76c9c03257c0782afef9d95321fa04096f60CNA: 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
- https://cert-portal.siemens.com/productcert/html/ssa-784472.htmlADP: siemens-SADP
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