| From 837f21aacf5a714c23ddaadbbc5212f9b661e3f7 Mon Sep 17 00:00:00 2001 |
| From: Prasad J Pandit <pjp@fedoraproject.org> |
| Date: Fri, 20 Nov 2015 11:50:31 +0530 |
| Subject: [PATCH] net: pcnet: add check to validate receive data |
| size(CVE-2015-7504) |
| |
| In loopback mode, pcnet_receive routine appends CRC code to the |
| receive buffer. If the data size given is same as the buffer size, |
| the appended CRC code overwrites 4 bytes after s->buffer. Added a |
| check to avoid that. |
| |
| Reported by: Qinghao Tang <luodalongde@gmail.com> |
| Cc: qemu-stable@nongnu.org |
| Reviewed-by: Michael S. Tsirkin <mst@redhat.com> |
| Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> |
| Signed-off-by: Jason Wang <jasowang@redhat.com> |
| |
| Upstream-Status: Backport |
| |
| http://git.qemu.org/?p=qemu.git;a=commit;h=837f21aacf5a714c23ddaadbbc5212f9b661e3f7 |
| |
| CVE: CVE-2015-7504 |
| [Yocto # 9013] |
| |
| Signed-off-by: Armin Kuster <akuster@mvista.com> |
| |
| --- |
| hw/net/pcnet.c | 8 +++++--- |
| 1 file changed, 5 insertions(+), 3 deletions(-) |
| |
| Index: qemu-2.4.0/hw/net/pcnet.c |
| =================================================================== |
| --- qemu-2.4.0.orig/hw/net/pcnet.c |
| +++ qemu-2.4.0/hw/net/pcnet.c |
| @@ -1085,7 +1085,7 @@ ssize_t pcnet_receive(NetClientState *nc |
| uint32_t fcs = ~0; |
| uint8_t *p = src; |
| |
| - while (p != &src[size-4]) |
| + while (p != &src[size]) |
| CRC(fcs, *p++); |
| crc_err = (*(uint32_t *)p != htonl(fcs)); |
| } |
| @@ -1234,8 +1234,10 @@ static void pcnet_transmit(PCNetState *s |
| bcnt = 4096 - GET_FIELD(tmd.length, TMDL, BCNT); |
| |
| /* if multi-tmd packet outsizes s->buffer then skip it silently. |
| - Note: this is not what real hw does */ |
| - if (s->xmit_pos + bcnt > sizeof(s->buffer)) { |
| + * Note: this is not what real hw does. |
| + * Last four bytes of s->buffer are used to store CRC FCS code. |
| + */ |
| + if (s->xmit_pos + bcnt > sizeof(s->buffer) - 4) { |
| s->xmit_pos = -1; |
| goto txdone; |
| } |