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authorChristoph Hellwig <hch@lst.de>2017-01-30 13:15:41 +0100
committerBjorn Helgaas <bhelgaas@google.com>2017-02-02 10:35:46 -0600
commitdfef358bd1beb4e7b5c94eca944be9cd23dfc752 (patch)
treeb9a2afb38a4c2ac8ad31f49ec0d71fe9e5b1994c
parent030305d69fc6963c16003f50d7e8d74b02d0a143 (diff)
PCI/MSI: Don't apply affinity if there aren't enough vectors left
Bart reported a problem wіth an out of bounds access in the low-level IRQ affinity code, which we root caused to the qla2xxx driver assigning all its MSI-X vectors to the pre and post vectors, and not having any left for the actually spread IRQs. Fix this issue by not asking for affinity assignment when there are no vectors to assign left. Fixes: 402723ad5c62 ("PCI/MSI: Provide pci_alloc_irq_vectors_affinity()") Link: https://lkml.kernel.org/r/1485359225.3093.3.camel@sandisk.com Reported-by: Bart Van Assche <bart.vanassche@sandisk.com> Tested-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
-rw-r--r--drivers/pci/msi.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 50c5003295ca..7f73bacf13ed 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1206,6 +1206,16 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
if (flags & PCI_IRQ_AFFINITY) {
if (!affd)
affd = &msi_default_affd;
+
+ if (affd->pre_vectors + affd->post_vectors > min_vecs)
+ return -EINVAL;
+
+ /*
+ * If there aren't any vectors left after applying the pre/post
+ * vectors don't bother with assigning affinity.
+ */
+ if (affd->pre_vectors + affd->post_vectors == min_vecs)
+ affd = NULL;
} else {
if (WARN_ON(affd))
affd = NULL;