futex: Clear stale exiting pointer in futex_lock_pi() retry path (Linux Linux)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.13 % · percentile 3 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Modified
Description
In the Linux kernel, the following vulnerability has been resolved: futex: Clear stale exiting pointer in futex_lock_pi() retry path Fuzzying/stressing futexes triggered: WARNING: kernel/futex/core.c:825 at wait_for_owner_exiting+0x7a/0x80, CPU#11: futex_lock_pi_s/524 When futex_lock_pi_atomic() sees the owner is exiting, it returns -EBUSY and stores a refcounted task pointer in 'exiting'. After wait_for_owner_exiting() consumes that reference, the local pointer is never reset to nil. Upon a retry, if futex_lock_pi_atomic() returns a different error, the bogus pointer is passed to wait_for_owner_exiting(). CPU0 CPU1 CPU2 futex_lock_pi(uaddr) // acquires the PI futex exit() futex_cleanup_begin() futex_state = EXITING; futex_lock_pi(uaddr) futex_lock_pi_atomic() attach_to_pi_owner() // observes EXITING *exiting = owner; // takes ref return -EBUSY wait_for_owner_exiting(-EBUSY, owner) put_task_struct(); // drops ref // exiting still points to owner goto retry; futex_lock_pi_atomic() lock_pi_update_atomic() cmpxchg(uaddr) *uaddr ^= WAITERS // whatever // value changed return -EAGAIN; wait_for_owner_exiting(-EAGAIN, exiting) // stale WARN_ON_ONCE(exiting) Fix this by resetting upon retry, essentially aligning it with requeue_pi.
References
- https://git.kernel.org/stable/c/33095ae3bdde5e5c264d7e88a2f3e7703a26c7aa
- https://git.kernel.org/stable/c/e7824ec168d2ac883a213cd1f4d6cc0816002a85
- https://git.kernel.org/stable/c/5e8e06bf8909e79b4acd950cf578cfc2f10bbefa
- https://git.kernel.org/stable/c/de7c0c04ad868f2cee6671b11c0a6d20421af1da
- https://git.kernel.org/stable/c/7475dfad10a05a5bfadebf5f2499bd61b19ed293
- https://git.kernel.org/stable/c/92e47ad03e03dbb5515bdf06444bf6b1e147310d
- https://git.kernel.org/stable/c/71112e62807d1925dc3ae6188b11f8cfc85aec23
- https://git.kernel.org/stable/c/210d36d892de5195e6766c45519dfb1e65f3eb83
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2026-25448
- GCVE · GCVE-0-2026-31555
CERT-FR advisories
- CERTFR-2026-AVI-1298 — Multiples vulnérabilités dans les produits Siemens · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1229 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1093 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1066 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0985 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0956 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0954 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0927 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0926 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0880 — Multiples vulnérabilités dans les produits Siemens · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0864 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0833 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0696 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0548 — Multiples vulnérabilités dans le noyau Linux de Debian · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0547 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0519 — Multiples vulnérabilités dans Microsoft Azure Linux · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 4.4.255 < 4.5cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 4.9.255 < 4.10cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 4.14.158 < 4.15cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 4.19.172 < 4.20cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.4.1 < 5.5cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.5.1 < 5.10.253cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.11 < 5.15.203cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.16 < 6.1.168cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.2 < 6.6.131cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.7 < 6.12.80cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13 < 6.18.21cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.19 < 6.19.11cpe:2.3:o:linux:linux_kernel:5.5:-:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected 3ef240eaff36b8119ac9e2ea17cbf41179c930ba < 33095ae3bdde5e5c264d7e88a2f3e7703a26c7aa ; affected 3ef240eaff36b8119ac9e2ea17cbf41179c930ba < e7824ec168d2ac883a213cd1f4d6cc0816002a85 ; affected 3ef240eaff36b8119ac9e2ea17cbf41179c930ba < 5e8e06bf8909e79b4acd950cf578cfc2f10bbefa ; affected 3ef240eaff36b8119ac9e2ea17cbf41179c930ba < de7c0c04ad868f2cee6671b11c0a6d20421af1da ; affected 3ef240eaff36b8119ac9e2ea17cbf41179c930ba < 7475dfad10a05a5bfadebf5f2499bd61b19ed293 ; affected 3ef240eaff36b8119ac9e2ea17cbf41179c930ba < 92e47ad03e03dbb5515bdf06444bf6b1e147310d |
| Linux · Linux | affected 5.5 ; unaffected 0 < 5.5 ; unaffected 5.10.253 ≤ 5.10.* ; unaffected 5.15.203 ≤ 5.15.* ; unaffected 6.1.168 ≤ 6.1.* ; unaffected 6.6.131 ≤ 6.6.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |