summaryrefslogtreecommitdiff
path: root/net
diff options
context:
space:
mode:
authorFlorian Westphal <fw@strlen.de>2021-03-04 13:32:11 -0800
committerDavid S. Miller <davem@davemloft.net>2021-03-04 14:30:13 -0800
commit17aee05dc8822e354f5ad2d68ee39e3ba4b6acf2 (patch)
tree10b8a937d5859c77ac3e24fb19b5498b2227422b /net
parenteaeef1ce55ec9161e0c44ff27017777b1644b421 (diff)
mptcp: dispose initial struct socket when its subflow is closed
Christoph Paasch reported following crash: dst_release underflow WARNING: CPU: 0 PID: 1319 at net/core/dst.c:175 dst_release+0xc1/0xd0 net/core/dst.c:175 CPU: 0 PID: 1319 Comm: syz-executor217 Not tainted 5.11.0-rc6af8e85128b4d0d24083c5cac646e891227052e0c #70 Call Trace: rt_cache_route+0x12e/0x140 net/ipv4/route.c:1503 rt_set_nexthop.constprop.0+0x1fc/0x590 net/ipv4/route.c:1612 __mkroute_output net/ipv4/route.c:2484 [inline] ... The worker leaves msk->subflow alone even when it happened to close the subflow ssk associated with it. Fixes: 866f26f2a9c33b ("mptcp: always graft subflow socket to parent") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/157 Reported-by: Christoph Paasch <cpaasch@apple.com> Suggested-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/mptcp/protocol.c18
1 files changed, 12 insertions, 6 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index aa59101ffe54..a58da04bed71 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2116,6 +2116,14 @@ static struct sock *mptcp_subflow_get_retrans(const struct mptcp_sock *msk)
return backup;
}
+static void mptcp_dispose_initial_subflow(struct mptcp_sock *msk)
+{
+ if (msk->subflow) {
+ iput(SOCK_INODE(msk->subflow));
+ msk->subflow = NULL;
+ }
+}
+
/* subflow sockets can be either outgoing (connect) or incoming
* (accept).
*
@@ -2160,6 +2168,9 @@ static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
if (ssk == msk->last_snd)
msk->last_snd = NULL;
+
+ if (msk->subflow && ssk == msk->subflow->sk)
+ mptcp_dispose_initial_subflow(msk);
}
void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
@@ -2529,12 +2540,6 @@ static void __mptcp_destroy_sock(struct sock *sk)
might_sleep();
- /* dispose the ancillatory tcp socket, if any */
- if (msk->subflow) {
- iput(SOCK_INODE(msk->subflow));
- msk->subflow = NULL;
- }
-
/* be sure to always acquire the join list lock, to sync vs
* mptcp_finish_join().
*/
@@ -2559,6 +2564,7 @@ static void __mptcp_destroy_sock(struct sock *sk)
sk_stream_kill_queues(sk);
xfrm_sk_free_policy(sk);
sk_refcnt_debug_release(sk);
+ mptcp_dispose_initial_subflow(msk);
sock_put(sk);
}