Description
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
Metrics
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= 6be3b0db6db82cf056a72cc18042048edd27f8ee, < 8fc536e9f6856230f19c7d13e71af064b6a77b22; >= 6be3b0db6db82cf056a72cc18042048edd27f8ee, < c4c1ea36d83bf3c4569468ca5b8b614fda1bf821; >= 6be3b0db6db82cf056a72cc18042048edd27f8ee, < 25c8c7fb3b0b9668c7d05e209f58c158d2b020c7; >= 6be3b0db6db82cf056a72cc18042048edd27f8ee, < 42827d03f8009a6a218bacab153e21f39d6a121c; >= 6be3b0db6db82cf056a72cc18042048edd27f8ee, < 88697cf980222d5906a37bf47662dac0732e2a0f; >= 6be3b0db6db82cf056a72cc18042048edd27f8ee, < b5316e2b8614a87d8736941972441cb47bfd4491; >= 6be3b0db6db82cf056a72cc18042048edd27f8ee, < ec82ea4eb220164d854f8734ca5a35e23e577b94; >= 6be3b0db6db82cf056a72cc18042048edd27f8ee, < 7f2d76c9c03257c0782afef9d95321fa04096f60 |
| Linux | Linux | 5.0 |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) | >= V3.1.6, < * |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) | >= V3.1.7, < * |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) | >= V3.1.6, < * |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) | >= V3.1.7, < * |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) | >= V3.1.6, < * |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) | >= V3.1.7, < * |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) | >= V3.1.6, < * |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) | >= V3.1.7, < * |
| Siemens | SIMATIC S7-1500 TM MFP - GNU/Linux subsystem | < * |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) | >= V3.1.6, < * |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) | >= V3.1.7, < * |
References
- https://git.kernel.org/stable/c/25c8c7fb3b0b9668c7d05e209f58c158d2b020c7Patch
- https://git.kernel.org/stable/c/42827d03f8009a6a218bacab153e21f39d6a121cPatch
- https://git.kernel.org/stable/c/7f2d76c9c03257c0782afef9d95321fa04096f60Patch
- https://git.kernel.org/stable/c/88697cf980222d5906a37bf47662dac0732e2a0fPatch
- https://git.kernel.org/stable/c/8fc536e9f6856230f19c7d13e71af064b6a77b22Patch
- https://git.kernel.org/stable/c/b5316e2b8614a87d8736941972441cb47bfd4491Patch
- https://git.kernel.org/stable/c/c4c1ea36d83bf3c4569468ca5b8b614fda1bf821Patch
- https://git.kernel.org/stable/c/ec82ea4eb220164d854f8734ca5a35e23e577b94Patch
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
Timeline
- Published
- Jun 25, 2026
- Last modified
- Nov 10, 2026
- NVD status
- Modified