This is a note to let you know that I've just added the patch titled x86/apic: Handle zero vector gracefully in clear_vector_irq() to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-apic-handle-zero-vector-gracefully-in-clear_vector_irq.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 1bdb8970392a68489b469c3a330a1adb5ef61beb Mon Sep 17 00:00:00 2001 From: Keith Busch <keith.busch@xxxxxxxxx> Date: Wed, 27 Apr 2016 14:22:32 -0600 Subject: x86/apic: Handle zero vector gracefully in clear_vector_irq() From: Keith Busch <keith.busch@xxxxxxxxx> commit 1bdb8970392a68489b469c3a330a1adb5ef61beb upstream. If x86_vector_alloc_irq() fails x86_vector_free_irqs() is invoked to cleanup the already allocated vectors. This subsequently calls clear_vector_irq(). The failed irq has no vector assigned, which triggers the BUG_ON(!vector) in clear_vector_irq(). We cannot suppress the call to x86_vector_free_irqs() for the failed interrupt, because the other data related to this irq must be cleaned up as well. So calling clear_vector_irq() with vector == 0 is legitimate. Remove the BUG_ON and return if vector is zero, [ tglx: Massaged changelog ] Fixes: b5dc8e6c21e7 "x86/irq: Use hierarchical irqdomain to manage CPU interrupt vectors" Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/apic/vector.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -254,7 +254,8 @@ static void clear_irq_vector(int irq, st struct irq_desc *desc; int cpu, vector; - BUG_ON(!data->cfg.vector); + if (!data->cfg.vector) + return; vector = data->cfg.vector; for_each_cpu_and(cpu, data->domain, cpu_online_mask) Patches currently in stable-queue which might be from keith.busch@xxxxxxxxx are queue-4.4/block-loop-fix-filesystem-corruption-in-case-of-aio-dio.patch queue-4.4/x86-apic-handle-zero-vector-gracefully-in-clear_vector_irq.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html