[Xen-changelog] [qemu-xen master] net: rocker: fix an incorrect array bounds check

[patchbot@xxxxxxx]

commit a890821b79ccf2f0c5bb60253d70f72f91e52e4c
Author:     Prasad J Pandit <pjp@xxxxxxxxxxxxxxxxx>
AuthorDate: Mon Dec 28 16:24:08 2015 +0530
Commit:     Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
CommitDate: Fri Feb 5 12:04:14 2016 +0000

    net: rocker: fix an incorrect array bounds check
    
    While processing transmit(tx) descriptors in 'tx_consume' routine
    the switch emulator suffers from an off-by-one error, if a
    descriptor was to have more than allowed(ROCKER_TX_FRAGS_MAX=16)
    fragments. Fix an incorrect bounds check to avoid it.
    
    Reported-by: Qinghao Tang <luodalongde@xxxxxxxxx>
    Cc: qemu-stable@xxxxxxxxxx
    Signed-off-by: Prasad J Pandit <pjp@xxxxxxxxxxxxxxxxx>
    Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
 hw/net/rocker/rocker.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/hw/net/rocker/rocker.c b/hw/net/rocker/rocker.c
index 47d080f..7e4ec0a 100644
--- a/hw/net/rocker/rocker.c
+++ b/hw/net/rocker/rocker.c
@@ -234,6 +234,9 @@ static int tx_consume(Rocker *r, DescInfo *info)
         frag_addr = rocker_tlv_get_le64(tlvs[ROCKER_TLV_TX_FRAG_ATTR_ADDR]);
         frag_len = rocker_tlv_get_le16(tlvs[ROCKER_TLV_TX_FRAG_ATTR_LEN]);
 
+        if (iovcnt >= ROCKER_TX_FRAGS_MAX) {
+            goto err_too_many_frags;
+        }
         iov[iovcnt].iov_len = frag_len;
         iov[iovcnt].iov_base = g_malloc(frag_len);
         if (!iov[iovcnt].iov_base) {
@@ -246,10 +249,7 @@ static int tx_consume(Rocker *r, DescInfo *info)
             err = -ROCKER_ENXIO;
             goto err_bad_io;
         }
-
-        if (++iovcnt > ROCKER_TX_FRAGS_MAX) {
-            goto err_too_many_frags;
-        }
+        iovcnt++;
     }
 
     if (iovcnt) {
--
generated by git-patchbot for /home/xen/git/qemu-xen.git#master

_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog