From 9fe713202e4ef4ff0264d6ecfaea26bc4e50705b Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 16 Jul 2024 14:16:27 +0200 Subject: [PATCH] x86/IRQ: avoid double unlock in map_domain_pirq() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Forever since its introduction the main loop in the function dealing with multi-vector MSI had error exit points ("break") with different properties: In one case no IRQ descriptor lock is being held. Nevertheless the subsequent error cleanup path assumed such a lock would uniformly need releasing. Identify the case by setting "desc" to NULL, thus allowing the unlock to be skipped as necessary. This is CVE-2024-31143 / XSA-458. Coverity ID: 1605298 Fixes: d1b6d0a02489 ("x86: enable multi-vector MSI") Signed-off-by: Jan Beulich Reviewed-by: Roger Pau Monné master commit: 57338346f29cea7b183403561bdc5f407163b846 master date: 2024-07-16 14:09:14 +0200 --- xen/arch/x86/irq.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c index 80ce9d624f..efed4fe09f 100644 --- a/xen/arch/x86/irq.c +++ b/xen/arch/x86/irq.c @@ -2215,6 +2215,7 @@ int map_domain_pirq( set_domain_irq_pirq(d, irq, info); spin_unlock_irqrestore(&desc->lock, flags); + desc = NULL; info = NULL; irq = create_irq(NUMA_NO_NODE, true); @@ -2250,7 +2251,9 @@ int map_domain_pirq( if ( ret ) { - spin_unlock_irqrestore(&desc->lock, flags); + if ( desc ) + spin_unlock_irqrestore(&desc->lock, flags); + pci_disable_msi(msi_desc); if ( nr ) { -- 2.39.5