From 2e7577cd5ddc1f86d1b6c48caf3cfa87dbb14e34 Mon Sep 17 00:00:00 2001 From: Li RongQing Date: Thu, 5 Feb 2026 04:40:10 -0500 Subject: [PATCH] mshv: fix SRCU protection in irqfd resampler ack handler Replace hlist_for_each_entry_rcu() with hlist_for_each_entry_srcu() in mshv_irqfd_resampler_ack() to correctly handle SRCU-protected linked list traversal. The function uses SRCU (sleepable RCU) synchronization via partition->pt_irq_srcu, but was incorrectly using the RCU variant for list iteration. This could lead to race conditions when the list is modified concurrently. Also add srcu_read_lock_held() assertion as required by hlist_for_each_entry_srcu() to ensure we're in the proper read-side critical section. Fixes: 621191d709b14 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs") Signed-off-by: Li RongQing Reviewed-by: Anirudh Rayabharam (Microsoft) Acked-by: Stanislav Kinsburskii Signed-off-by: Wei Liu --- drivers/hv/mshv_eventfd.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/hv/mshv_eventfd.c b/drivers/hv/mshv_eventfd.c index 525b64a5acc2..5e0b10aeeaa2 100644 --- a/drivers/hv/mshv_eventfd.c +++ b/drivers/hv/mshv_eventfd.c @@ -87,8 +87,9 @@ static void mshv_irqfd_resampler_ack(struct mshv_irq_ack_notifier *mian) idx = srcu_read_lock(&partition->pt_irq_srcu); - hlist_for_each_entry_rcu(irqfd, &resampler->rsmplr_irqfd_list, - irqfd_resampler_hnode) { + hlist_for_each_entry_srcu(irqfd, &resampler->rsmplr_irqfd_list, + irqfd_resampler_hnode, + srcu_read_lock_held(&partition->pt_irq_srcu)) { if (hv_should_clear_interrupt(irqfd->irqfd_lapic_irq.lapic_control.interrupt_type)) hv_call_clear_virtual_interrupt(partition->pt_id); -- 2.30.2