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authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2022-09-29 00:25:37 +0900
committerDavid S. Miller <davem@davemloft.net>2022-10-03 07:56:02 +0100
commita91b750fd6629354460282bbf5146c01b05c4859 (patch)
tree4f7407a3955bcc7abdfa71a8a7def8c3c51334ca /net
parentae3ed15da5889263de372ff9df2e83e16acca4cb (diff)
net: rds: don't hold sock lock when cancelling work from rds_tcp_reset_callbacks()
syzbot is reporting lockdep warning at rds_tcp_reset_callbacks() [1], for commit ac3615e7f3cffe2a ("RDS: TCP: Reduce code duplication in rds_tcp_reset_callbacks()") added cancel_delayed_work_sync() into a section protected by lock_sock() without realizing that rds_send_xmit() might call lock_sock(). We don't need to protect cancel_delayed_work_sync() using lock_sock(), for even if rds_{send,recv}_worker() re-queued this work while __flush_work() from cancel_delayed_work_sync() was waiting for this work to complete, retried rds_{send,recv}_worker() is no-op due to the absence of RDS_CONN_UP bit. Link: https://syzkaller.appspot.com/bug?extid=78c55c7bc6f66e53dce2 [1] Reported-by: syzbot <syzbot+78c55c7bc6f66e53dce2@syzkaller.appspotmail.com> Co-developed-by: Hillf Danton <hdanton@sina.com> Signed-off-by: Hillf Danton <hdanton@sina.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Tested-by: syzbot <syzbot+78c55c7bc6f66e53dce2@syzkaller.appspotmail.com> Fixes: ac3615e7f3cffe2a ("RDS: TCP: Reduce code duplication in rds_tcp_reset_callbacks()") Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/rds/tcp.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/rds/tcp.c b/net/rds/tcp.c
index 73ee2771093d..d0ff413f697c 100644
--- a/net/rds/tcp.c
+++ b/net/rds/tcp.c
@@ -166,10 +166,10 @@ void rds_tcp_reset_callbacks(struct socket *sock,
*/
atomic_set(&cp->cp_state, RDS_CONN_RESETTING);
wait_event(cp->cp_waitq, !test_bit(RDS_IN_XMIT, &cp->cp_flags));
- lock_sock(osock->sk);
/* reset receive side state for rds_tcp_data_recv() for osock */
cancel_delayed_work_sync(&cp->cp_send_w);
cancel_delayed_work_sync(&cp->cp_recv_w);
+ lock_sock(osock->sk);
if (tc->t_tinc) {
rds_inc_put(&tc->t_tinc->ti_inc);
tc->t_tinc = NULL;