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[16/35] net: ne2000: check ring buffer control registers

Message ID 1458581313-19045-17-git-send-email-mdroth@linux.vnet.ibm.com
State New
Headers show

Commit Message

Michael Roth March 21, 2016, 5:28 p.m. UTC 
From: Prasad J Pandit <pjp@fedoraproject.org>

Ne2000 NIC uses ring buffer of NE2000_MEM_SIZE(49152)
bytes to process network packets. Registers PSTART & PSTOP
define ring buffer size & location. Setting these registers
to invalid values could lead to infinite loop or OOB r/w
access issues. Add check to avoid it.

Reported-by: Yang Hongke <yanghongke@huawei.com>
Tested-by: Yang Hongke <yanghongke@huawei.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
(cherry picked from commit 415ab35a441eca767d033a2702223e785b9d5190)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 hw/net/ne2000.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox

Patch

diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c
index 010f9ef..84a7263 100644
--- a/hw/net/ne2000.c
+++ b/hw/net/ne2000.c
@@ -154,6 +154,10 @@  static int ne2000_buffer_full(NE2000State *s)
 {
     int avail, index, boundary;
 
+    if (s->stop <= s->start) {
+        return 1;
+    }
+
     index = s->curpag << 8;
     boundary = s->boundary << 8;
     if (index < boundary)