qemu/0024-net-pcnet-add-check-to-validate-receive-data-size-CV.patch
Cole Robinson bf445db9ab Fix abort in abort in bdrv_error_action (bz #1277482)
Fix SSE4 emulation with accel=tcg (bz #1270703)
CVE-2015-8345: Fix infinite loop in eepro100 (bz #1285214)
CVE-2015-7504: Fix heap overflow in pcnet (bz #1286543)
CVE-2015-7512: Fix buffer overflow in pcnet (bz #1286549)
2015-12-07 14:23:27 -05:00

48 lines
1.8 KiB
Diff

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>
(cherry picked from commit 837f21aacf5a714c23ddaadbbc5212f9b661e3f7)
---
hw/net/pcnet.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c
index 68b9981..03a56b2 100644
--- a/hw/net/pcnet.c
+++ b/hw/net/pcnet.c
@@ -1094,7 +1094,7 @@ ssize_t pcnet_receive(NetClientState *nc, const uint8_t *buf, size_t size_)
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));
}
@@ -1243,8 +1243,10 @@ 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;
}