Re: [patch 02/10] rseq: Protect rseq_reset() against interrupts
From: Dmitry Vyukov <dvyukov@google.com>
Date: 2026-04-29 08:22:50
Also in:
lkml, regressions
On Wed, 29 Apr 2026 at 01:33, Thomas Gleixner [off-list ref] wrote:
quoted hunk ↗ jump to hunk
rseq_reset() uses memset() to clear the tasks rseq data. That's racy against membarrier() and preemption. Guard it with irqsave to cure this. Fixes: faba9d250eae ("rseq: Introduce struct rseq_data") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Cc: stable@vger.kernel.org --- include/linux/rseq.h | 1 + 1 file changed, 1 insertion(+)--- a/include/linux/rseq.h +++ b/include/linux/rseq.h@@ -119,6 +119,7 @@ static inline void rseq_virt_userspace_e static inline void rseq_reset(struct task_struct *t) { + guard(irqsave)();
This may deserve a comment for future readers, but otherwise: Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
memset(&t->rseq, 0, sizeof(t->rseq));
t->rseq.ids.cpu_id = RSEQ_CPU_ID_UNINITIALIZED;
}