[Xen-changelog] [qemu-xen stable-4.4] net: cadence_gem: check packet size in gem_recieve

[patchbot@xxxxxxx]

commit a37e0e9de748f58b793a83e5d680f474c640f87e
Author:     Prasad J Pandit <pjp@xxxxxxxxxxxxxxxxx>
AuthorDate: Fri Jan 15 12:30:40 2016 +0530
Commit:     Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
CommitDate: Fri Feb 5 14:53:53 2016 +0000

    net: cadence_gem: check packet size in gem_recieve
    
    While receiving packets in 'gem_receive' routine, if Frame Check
    Sequence(FCS) is enabled, it copies the packet into a local
    buffer without checking its size. Add check to validate packet
    length against the buffer size to avoid buffer overflow.
    
    Reported-by: Ling Liu <liuling-it@xxxxxx>
    Signed-off-by: Prasad J Pandit <pjp@xxxxxxxxxxxxxxxxx>
    Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
 hw/net/cadence_gem.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
index 4a355bb..770965c 100644
--- a/hw/net/cadence_gem.c
+++ b/hw/net/cadence_gem.c
@@ -640,6 +640,10 @@ static ssize_t gem_receive(NetClientState *nc, const 
uint8_t *buf, size_t size)
         unsigned crc_val;
         int      crc_offset;
 
+        if (size > sizeof(rxbuf) - sizeof(crc_val)) {
+            size = sizeof(rxbuf) - sizeof(crc_val);
+        }
+        bytes_to_copy = size;
         /* The application wants the FCS field, which QEMU does not provide.
          * We must try and caclculate one.
          */
--
generated by git-patchbot for /home/xen/git/qemu-xen.git#stable-4.4

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