ipv4: Fix crash in dst_release when udp_sendmsg route lookup fails.
As reported by Eric:
[11483.697233] IP: [<c12b0638>] dst_release+0x18/0x60
...
[11483.697741] Call Trace:
[11483.697764] [<c12fc9d2>] udp_sendmsg+0x282/0x6e0
[11483.697790] [<c12a1c01>] ? memcpy_toiovec+0x51/0x70
[11483.697818] [<c12dbd90>] ? ip_generic_getfrag+0x0/0xb0
The pointer passed to dst_release() is -EINVAL, that's because
we leave an error pointer in the local variable "rt" by accident.
NULL it out to fix the bug.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 95e0c2c..c9a73e5 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -925,6 +925,7 @@
rt = ip_route_output_flow(net, &fl, sk);
if (IS_ERR(rt)) {
err = PTR_ERR(rt);
+ rt = NULL;
if (err == -ENETUNREACH)
IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
goto out;