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authorJason Wang <jasowang@redhat.com>2012-05-17 13:25:43 +0800
committerAnthony Liguori <aliguori@us.ibm.com>2012-06-27 16:27:00 -0500
commitfcce6fd25f3e233f9da9ef01230a668ab35bd343 (patch)
tree45ce16ff88d35149a272010af694e7c505ef8978
parent2624bab836662d37f08336408a99d97652fc9c4d (diff)
downloadqemu-arm-fcce6fd25f3e233f9da9ef01230a668ab35bd343.tar.gz
rtl8139: validate rx ring before receiving packets
Commit ff71f2e8cacefae99179993204172bc65e4303df prevent the possible crash during initialization of linux driver by checking the operating mode.This seems too strict as: - the real card could still work in mode other than normal - some buggy driver who does not set correct opmode after eeprom access So, considering rx ring address were reset to zero (which could be safely trated as an address not intened to DMA to), in order to both letting old guest work and preventing the unexpected DMA to guest, we can forbid packet receiving when rx ring address is zero. Tested-by: Avi Kivity <avi@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
-rw-r--r--hw/rtl8139.c22
1 files changed, 12 insertions, 10 deletions
diff --git a/hw/rtl8139.c b/hw/rtl8139.c
index f6f144b525..7b150475f4 100644
--- a/hw/rtl8139.c
+++ b/hw/rtl8139.c
@@ -781,6 +781,13 @@ static inline dma_addr_t rtl8139_addr64(uint32_t low, uint32_t high)
#endif
}
+/* Workaround for buggy guest driver such as linux who allocates rx
+ * rings after the receiver were enabled. */
+static bool rtl8139_cp_rx_valid(RTL8139State *s)
+{
+ return !(s->RxRingAddrLO == 0 && s->RxRingAddrHI == 0);
+}
+
static int rtl8139_can_receive(VLANClientState *nc)
{
RTL8139State *s = DO_UPCAST(NICState, nc, nc)->opaque;
@@ -791,11 +798,8 @@ static int rtl8139_can_receive(VLANClientState *nc)
return 1;
if (!rtl8139_receiver_enabled(s))
return 1;
- /* network/host communication happens only in normal mode */
- if ((s->Cfg9346 & Chip9346_op_mask) != Cfg9346_Normal)
- return 0;
- if (rtl8139_cp_receiver_enabled(s)) {
+ if (rtl8139_cp_receiver_enabled(s) && rtl8139_cp_rx_valid(s)) {
/* ??? Flow control not implemented in c+ mode.
This is a hack to work around slirp deficiencies anyway. */
return 1;
@@ -836,12 +840,6 @@ static ssize_t rtl8139_do_receive(VLANClientState *nc, const uint8_t *buf, size_
return -1;
}
- /* check whether we are in normal mode */
- if ((s->Cfg9346 & Chip9346_op_mask) != Cfg9346_Normal) {
- DPRINTF("not in normal op mode\n");
- return -1;
- }
-
/* XXX: check this */
if (s->RxConfig & AcceptAllPhys) {
/* promiscuous: receive all */
@@ -946,6 +944,10 @@ static ssize_t rtl8139_do_receive(VLANClientState *nc, const uint8_t *buf, size_
if (rtl8139_cp_receiver_enabled(s))
{
+ if (!rtl8139_cp_rx_valid(s)) {
+ return size;
+ }
+
DPRINTF("in C+ Rx mode ================\n");
/* begin C+ receiver mode */