[Qemu-devel] [PATCH 3/3] scsi: megasas: check 'read_queue_head' index value

[P J P <ppandit@redhat.com>]

From: Prasad J Pandit <pjp@fedoraproject.org>

While doing MegaRAID SAS controller command frame lookup, routine
'megasas_lookup_frame' uses 'read_queue_head' value as an index
into 'frames[MEGASAS_MAX_FRAMES=2048]' array. Limit its value
within array bounds to avoid any OOB access.

Reported-by: Li Qiang <liqiang6-s@360.cn>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
 hw/scsi/megasas.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c
index 7c08932..76d57f9 100644
--- a/hw/scsi/megasas.c
+++ b/hw/scsi/megasas.c
@@ -649,8 +649,10 @@ static int megasas_init_firmware(MegasasState *s, MegasasCmd *cmd)
     pa_lo = le32_to_cpu(initq->pi_addr_lo);
     pa_hi = le32_to_cpu(initq->pi_addr_hi);
     s->producer_pa = ((uint64_t) pa_hi << 32) | pa_lo;
-    s->reply_queue_head = ldl_le_pci_dma(pcid, s->producer_pa);
-    s->reply_queue_tail = ldl_le_pci_dma(pcid, s->consumer_pa);
+    s->reply_queue_head = \
+        ldl_le_pci_dma(pcid, s->producer_pa) % MEGASAS_MAX_FRAMES;
+    s->reply_queue_tail = \
+        ldl_le_pci_dma(pcid, s->consumer_pa) % MEGASAS_MAX_FRAMES;
     flags = le32_to_cpu(initq->flags);
     if (flags & MFI_QUEUE_FLAG_CONTEXT64) {
         s->flags |= MEGASAS_MASK_USE_QUEUE64;
-- 
2.5.5