[PATCH v2] scsi: mpt3sas: avoid out-of-bounds cpumask_of_node() call in _base_assign_reply_queues()

[Ivy Lopez <skunkolee@gmail.com>]

dev_to_node() can return NUMA_NO_NODE (-1) on systems without NUMA
topology information for the PCI device, such as single-socket
boards that don't expose device-to-node affinity. Passing -1
directly into cpumask_of_node() indexes node_to_cpumask_map[-1],
an out-of-bounds array read caught by UBSAN:

  UBSAN: array-index-out-of-bounds in arch/x86/include/asm/topology.h:72:28
  index -1 is out of range for type 'cpumask *[1024]'

Fall back to cpu_online_mask when no NUMA node is available, rather
than assuming dev_to_node() always returns a valid node index.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=221294
Suggested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Fixes: 728bbc6cbff7 ("scsi: mpt3sas: Affinity high iops queues IRQs to local node")
Signed-off-by: Ivy Lopez <skunkolee@gmail.com>
---
 Changes in v2:
- Drop superfluous parentheses around dev_to_node() call.
- Split overly long ternary assignment line.
- Add Fixes: tag per checkpatch --strict suggestion.
- Link to v1: https://lore.kernel.org/r/20260817221300.43286-1-skunkolee@gmail.com

 drivers/scsi/mpt3sas/mpt3sas_base.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 79052f2accbd..ce5a5882acc8 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -3238,7 +3238,10 @@ _base_assign_reply_queues(struct MPT3SAS_ADAPTER *ioc)
 		 * corresponding to high iops queues.
 		 */
 		if (ioc->high_iops_queues) {
-			mask = cpumask_of_node(dev_to_node(&ioc->pdev->dev));
+			int node = dev_to_node(&ioc->pdev->dev);
+
+			mask = (node == NUMA_NO_NODE) ?
+				cpu_online_mask : cpumask_of_node(node);
 			for (index = 0; index < ioc->high_iops_queues;
 			    index++) {
 				irq = pci_irq_vector(ioc->pdev, index);
-- 
2.55.0