This is a note to let you know that I've just added the patch titled
mptcp: fix sleep in atomic at close time
to the 6.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mptcp-fix-sleep-in-atomic-at-close-time.patch
and it can be found in the queue-6.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6ae13ed2327aecb5600c45ce7e842e3a85686458
Author: Paolo Abeni <pabeni@xxxxxxxxxx>
Date: Mon Nov 28 16:42:38 2022 +0100
mptcp: fix sleep in atomic at close time
[ Upstream commit b4f166651d03b5484fa179817ba8ad4899a5a6ac ]
Matt reported a splat at msk close time:
BUG: sleeping function called from invalid context at net/mptcp/protocol.c:2877
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 155, name: packetdrill
preempt_count: 201, expected: 0
RCU nest depth: 0, expected: 0
4 locks held by packetdrill/155:
#0: ffff888001536990 (&sb->s_type->i_mutex_key#6){+.+.}-{3:3}, at: __sock_release (net/socket.c:650)
#1: ffff88800b498130 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close (net/mptcp/protocol.c:2973)
#2: ffff88800b49a130 (sk_lock-AF_INET/1){+.+.}-{0:0}, at: __mptcp_close_ssk (net/mptcp/protocol.c:2363)
#3: ffff88800b49a0b0 (slock-AF_INET){+...}-{2:2}, at: __lock_sock_fast (include/net/sock.h:1820)
Preemption disabled at:
0x0
CPU: 1 PID: 155 Comm: packetdrill Not tainted 6.1.0-rc5 #365
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4))
__might_resched.cold (kernel/sched/core.c:9891)
__mptcp_destroy_sock (include/linux/kernel.h:110)
__mptcp_close (net/mptcp/protocol.c:2959)
mptcp_subflow_queue_clean (include/net/sock.h:1777)
__mptcp_close_ssk (net/mptcp/protocol.c:2363)
mptcp_destroy_common (net/mptcp/protocol.c:3170)
mptcp_destroy (include/net/sock.h:1495)
__mptcp_destroy_sock (net/mptcp/protocol.c:2886)
__mptcp_close (net/mptcp/protocol.c:2959)
mptcp_close (net/mptcp/protocol.c:2974)
inet_release (net/ipv4/af_inet.c:432)
__sock_release (net/socket.c:651)
sock_close (net/socket.c:1367)
__fput (fs/file_table.c:320)
task_work_run (kernel/task_work.c:181 (discriminator 1))
exit_to_user_mode_prepare (include/linux/resume_user_mode.h:49)
syscall_exit_to_user_mode (kernel/entry/common.c:130)
do_syscall_64 (arch/x86/entry/common.c:87)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
We can't call mptcp_close under the 'fast' socket lock variant, replace
it with a sock_lock_nested() as the relevant code is already under the
listening msk socket lock protection.
Reported-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/316
Fixes: 30e51b923e43 ("mptcp: fix unreleased socket in accept queue")
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Reviewed-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Signed-off-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 02a54d59697b..2159b5f9988f 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1745,16 +1745,16 @@ void mptcp_subflow_queue_clean(struct sock *listener_ssk)
for (msk = head; msk; msk = next) {
struct sock *sk = (struct sock *)msk;
- bool slow, do_cancel_work;
+ bool do_cancel_work;
sock_hold(sk);
- slow = lock_sock_fast_nested(sk);
+ lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
next = msk->dl_next;
msk->first = NULL;
msk->dl_next = NULL;
do_cancel_work = __mptcp_close(sk, 0);
- unlock_sock_fast(sk, slow);
+ release_sock(sk);
if (do_cancel_work)
mptcp_cancel_work(sk);
sock_put(sk);
