From b373cd31bd40fff153ecbeb4695b8667db28e4e0 Mon Sep 17 00:00:00 2001

From: Xiao Wang <jasowang@redhat.com>

Date: Fri, 11 Jan 2019 07:58:57 +0000

Subject: [PATCH 02/11] rtl8139: fix possible out of bound access

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RH-Author: Xiao Wang <jasowang@redhat.com>

Message-id: <20190111075904.2030-3-jasowang@redhat.com>

Patchwork-id: 83975

O-Subject: [RHEL8 qemu-kvm PATCH 2/9] rtl8139: fix possible out of bound access

Bugzilla: 1636784

RH-Acked-by: Thomas Huth <thuth@redhat.com>

RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>

RH-Acked-by: Jens Freimann <jfreimann@redhat.com>

RH-Acked-by: Maxime Coquelin <maxime.coquelin@redhat.com>

RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>

In rtl8139_do_receive(), we try to assign size_ to size which converts

from size_t to integer. This will cause troubles when size_ is greater

INT_MAX, this will lead a negative value in size and it can then pass

the check of size < MIN_BUF_SIZE which may lead out of bound access of

for both buf and buf1.

Fixing by converting the type of size to size_t.

CC: qemu-stable@nongnu.org

Reported-by: Daniel Shapira <daniel@twistlock.com>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

Signed-off-by: Jason Wang <jasowang@redhat.com>

(cherry picked from commit 1a326646fef38782e5542280040ec3ea23e4a730)

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 hw/net/rtl8139.c | 8 ++++----

 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/hw/net/rtl8139.c b/hw/net/rtl8139.c

index 05453e7..0c916b7 100644

--- a/hw/net/rtl8139.c

+++ b/hw/net/rtl8139.c

@@ -817,7 +817,7 @@ static ssize_t rtl8139_do_receive(NetClientState *nc, const uint8_t *buf, size_t

     RTL8139State *s = qemu_get_nic_opaque(nc);

     PCIDevice *d = PCI_DEVICE(s);

     /* size is the length of the buffer passed to the driver */

-    int size = size_;

+    size_t size = size_;

     const uint8_t *dot1q_buf = NULL;

     uint32_t packet_header = 0;

@@ -826,7 +826,7 @@ static ssize_t rtl8139_do_receive(NetClientState *nc, const uint8_t *buf, size_t

     static const uint8_t broadcast_macaddr[6] =

         { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };

-    DPRINTF(">>> received len=%d\n", size);

+    DPRINTF(">>> received len=%zu\n", size);

     /* test if board clock is stopped */

     if (!s->clock_enabled)

@@ -1035,7 +1035,7 @@ static ssize_t rtl8139_do_receive(NetClientState *nc, const uint8_t *buf, size_t

         if (size+4 > rx_space)

         {

-            DPRINTF("C+ Rx mode : descriptor %d size %d received %d + 4\n",

+            DPRINTF("C+ Rx mode : descriptor %d size %d received %zu + 4\n",

                 descriptor, rx_space, size);

             s->IntrStatus |= RxOverflow;

@@ -1148,7 +1148,7 @@ static ssize_t rtl8139_do_receive(NetClientState *nc, const uint8_t *buf, size_t

         if (avail != 0 && RX_ALIGN(size + 8) >= avail)

         {

             DPRINTF("rx overflow: rx buffer length %d head 0x%04x "

-                "read 0x%04x === available 0x%04x need 0x%04x\n",

+                "read 0x%04x === available 0x%04x need 0x%04zx\n",

                 s->RxBufferSize, s->RxBufAddr, s->RxBufPtr, avail, size + 8);

             s->IntrStatus |= RxOverflow;

-- 

1.8.3.1