From: Nam Cao Date: Mon, 4 Aug 2025 10:07:27 +0000 (+0200) Subject: powerpc/pseries/msi: Fix potential underflow and leak issue X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=3443ff3be6e59b80d74036bb39f5b6409eb23cc9;p=users%2Fhch%2Fmisc.git powerpc/pseries/msi: Fix potential underflow and leak issue pseries_irq_domain_alloc() allocates interrupts at parent's interrupt domain. If it fails in the progress, all allocated interrupts are freed. The number of successfully allocated interrupts so far is stored "i". However, "i - 1" interrupts are freed. This is broken: - One interrupt is not be freed - If "i" is zero, "i - 1" wraps around Correct the number of freed interrupts to 'i'. Fixes: a5f3d2c17b07 ("powerpc/pseries/pci: Add MSI domains") Signed-off-by: Nam Cao Cc: stable@vger.kernel.org Reviewed-by: Cédric Le Goater Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/a980067f2b256bf716b4cd713bc1095966eed8cd.1754300646.git.namcao@linutronix.de --- diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c index ee1c8c6898a3..9dc294de631f 100644 --- a/arch/powerpc/platforms/pseries/msi.c +++ b/arch/powerpc/platforms/pseries/msi.c @@ -593,7 +593,7 @@ static int pseries_irq_domain_alloc(struct irq_domain *domain, unsigned int virq out: /* TODO: handle RTAS cleanup in ->msi_finish() ? */ - irq_domain_free_irqs_parent(domain, virq, i - 1); + irq_domain_free_irqs_parent(domain, virq, i); return ret; }