From 4d62121ce9b58ea23c8d62207cbc604e98ecdc0a Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 30 May 2025 10:16:47 +0100 Subject: [PATCH] KVM: arm64: vgic-debug: Avoid dereferencing NULL ITE pointer Dan reports that iterating over a device ITEs can legitimately lead to a NULL pointer, and that the NULL check is placed *after* the pointer has already been dereferenced. Hoist the pointer check as early as possible and be done with it. Reported-by: Dan Carpenter Fixes: 30deb51a677b ("KVM: arm64: vgic-its: Add debugfs interface to expose ITS tables") Link: https://lore.kernel.org/r/aDBylI1YnjPatAbr@stanley.mountain Cc: Jing Zhang Link: https://lore.kernel.org/r/20250530091647.1152489-1-maz@kernel.org Signed-off-by: Marc Zyngier --- arch/arm64/kvm/vgic/vgic-debug.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/vgic/vgic-debug.c b/arch/arm64/kvm/vgic/vgic-debug.c index f8425f381de9..2684f273d9e1 100644 --- a/arch/arm64/kvm/vgic/vgic-debug.c +++ b/arch/arm64/kvm/vgic/vgic-debug.c @@ -490,6 +490,9 @@ static int vgic_its_debug_show(struct seq_file *s, void *v) struct its_device *dev = iter->dev; struct its_ite *ite = iter->ite; + if (!ite) + return 0; + if (list_is_first(&ite->ite_list, &dev->itt_head)) { seq_printf(s, "\n"); seq_printf(s, "Device ID: 0x%x, Event ID Range: [0 - %llu]\n", @@ -498,7 +501,7 @@ static int vgic_its_debug_show(struct seq_file *s, void *v) seq_printf(s, "-----------------------------------------------\n"); } - if (ite && ite->irq && ite->collection) { + if (ite->irq && ite->collection) { seq_printf(s, "%8u %8u %8u %8u %8u %2d\n", ite->event_id, ite->irq->intid, ite->irq->hwintid, ite->collection->target_addr, -- 2.25.1