CVE-2026-43115

Summary

In the Linux kernel, the following vulnerability has been resolved:

srcu: Use irq_work to start GP in tiny SRCU

Tiny SRCU's srcu_gp_start_if_needed() directly calls schedule_work(), which acquires the workqueue pool->lock.

This causes a lockdep splat when call_srcu() is called with a scheduler lock held, due to:

call_srcu() [holding pi_lock] srcu_gp_start_if_needed() schedule_work() -> pool->lock

workqueue_init() / create_worker() [holding pool->lock] wake_up_process() -> try_to_wake_up() -> pi_lock

Also add irq_work_sync() to cleanup_srcu_struct() to prevent a use-after-free if a queued irq_work fires after cleanup begins.

Tested with rcutorture SRCU-T and no lockdep warnings.

[ Thanks to Boqun for similar fix in patch "rcu: Use an intermediate irq_work to start process_srcu()" ]

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxd8be81735aa89413b333de488251f0e64e2be591 < bb37286db65368cb72ba8757ad86299c4e4a73fcaffected
LinuxLinuxd8be81735aa89413b333de488251f0e64e2be591 < a6fc88b22bc8d12ad52e8412c667ec0f5bf055afaffected
LinuxLinux4.12affected
LinuxLinux0 < 4.12unaffected
LinuxLinux6.19.14 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References