Neither the failure or success paths of ping_v6_sendmsg release the dst it acquires. This leads to a flood of warnings from "net/core/dst.c:288 dst_release" on older kernels that don't have 8bf4ada2e21378816b28205427ee6b0e1ca4c5f1 backported.
That patch optimistically hoped this had been fixed post 3.10, but it seems at least one case wasn't, where I've seen this triggered a lot from machines doing unprivileged icmp sockets. Cc: Martin Lau <ka...@fb.com> Signed-off-by: Dave Jones <da...@codemonkey.org.uk> diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c index 0900352c924c..0e983b694ee8 100644 --- a/net/ipv6/ping.c +++ b/net/ipv6/ping.c @@ -126,8 +126,10 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) rt = (struct rt6_info *) dst; np = inet6_sk(sk); - if (!np) - return -EBADF; + if (!np) { + err = -EBADF; + goto dst_err_out; + } if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) fl6.flowi6_oif = np->mcast_oif; @@ -163,6 +165,9 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) } release_sock(sk); +dst_err_out: + dst_release(dst); + if (err) return err;