[LTP] [PATCH v4 0/2] Reproducer for ghostlock

[Andrea Cervesato]

Test for CVE-2026-43499 (GhostLock), a stack use-after-free in the
rtmutex PI code, fixed in kernel v7.1:
3bfdc63936dd ("rtmutex: Use waiter::task instead of current in remove_waiter()")

Reproducer based on the Nebula Security writeup and open-sourced PoC
(https://nebusec.ai/research/ionstack-part-2/, https://github.com/NebuSec/CyberMeowfia).
Beware, this test will crash the system on a vulnerable kernel.

Assisted by Kimi K3 for the analysis and written mostly with Gemini Pro
3.1 Max.

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
Changes in v4:
- handle runtime inside the test
- increase futext wait so we don't TBROK before runtime
- comment prctl() syscall
- move static vars out of the run function
- Link to v3: https://lore.kernel.org/20260803-cve-ghostlock-v3-0-cde83fa429b7@suse.com

Changes in v3:
- improve sync mechanism
- fix lapi imports
- Link to v2: https://lore.kernel.org/20260803-cve-ghostlock-v2-0-b60588853140@suse.com

Changes in v2:
- fix build
- fix 32bit run
- Link to v1: https://lore.kernel.org/20260801-cve-ghostlock-v1-0-178f698f9702@suse.com

---
Andrea Cervesato (2):
      lapi/prctl: add more fallback definitions
      cve: add CVE-2026-43499 reproducer

 configure.ac              |   2 +
 include/lapi/prctl.h      |  25 +++++
 runtest/cve               |   1 +
 testcases/cve/.gitignore  |   1 +
 testcases/cve/Makefile    |   1 +
 testcases/cve/ghostlock.c | 258 ++++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 288 insertions(+)
---
base-commit: 9118a480cc68700f27944aab817e0202e9e6136c
change-id: 20260801-cve-ghostlock-6ee4b2f69fd6

Best regards,
--  
Andrea Cervesato <andrea.cervesato@suse.com>