Description
In the Linux kernel, the following vulnerability has been resolved: irq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT On PREEMPT_RT, non-HARD irq_work runs in per-CPU kthreads via run_irq_workd(), so irq_work_sync() uses rcuwait() to wait for BUSY==0. After irq_work_single() clears BUSY via atomic_cmpxchg(), it still dereferences @work for irq_work_is_hard() and rcuwait_wake_up(). An irq_work_sync() caller on another CPU that enters after BUSY is cleared can observe BUSY==0 immediately, return, and free the work before those accesses complete — causing a use-after-free. Fix this by wrapping run_irq_workd() in guard(rcu)() so that the entire irq_work_single() execution is within an RCU read-side critical section. Then add synchronize_rcu() in irq_work_sync() after rcuwait_wait_event() to ensure the caller waits for the RCU grace period before returning, preventing premature frees.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
810979682ccc98dbd83f341c18a2e556c30a7164 to < 2dc79362302922cb18f35e262712b5e58de65442affected810979682ccc98dbd83f341c18a2e556c30a7164 to < eef4f71b46a9929ac33e968538c9dd5d96a02460affected810979682ccc98dbd83f341c18a2e556c30a7164 to < 684a78183c54c23e70d1cba320f7fc184604210baffected810979682ccc98dbd83f341c18a2e556c30a7164 to < 18c0456ea2615b1a743a6db739c74411c3b42bc6affected810979682ccc98dbd83f341c18a2e556c30a7164 to < 81b582784518196eff1050212a046bc29d3a05ddaffected810979682ccc98dbd83f341c18a2e556c30a7164 to < 91840be8f710370607f949a627e070896faeddb8affected
Linux Linux
Default version status: affected
5.16affected0 to < 5.16unaffected6.1.175 to ≤ 6.1.*unaffected6.6.142 to ≤ 6.6.*unaffected6.12.92 to ≤ 6.12.*unaffected6.18.34 to ≤ 6.18.*unaffected7.0.11 to ≤ 7.0.*unaffected7.1 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/2dc79362302922cb18f35e262712b5e58de65442 ↗
- https://git.kernel.org/stable/c/eef4f71b46a9929ac33e968538c9dd5d96a02460 ↗
- https://git.kernel.org/stable/c/684a78183c54c23e70d1cba320f7fc184604210b ↗
- https://git.kernel.org/stable/c/18c0456ea2615b1a743a6db739c74411c3b42bc6 ↗
- https://git.kernel.org/stable/c/81b582784518196eff1050212a046bc29d3a05dd ↗
- https://git.kernel.org/stable/c/91840be8f710370607f949a627e070896faeddb8 ↗