From: Dominique Martinet <asmadeus@xxxxxxxxxxxxx> commit 52f1c45dde9136f964d63a77d19826c8a74e2c7f upstream. syzbot reported a double-lock here and we no longer need this lock after requests have been moved off to local list: just drop the lock earlier. Link: https://lkml.kernel.org/r/20220904064028.1305220-1-asmadeus@xxxxxxxxxxxxx Reported-by: syzbot+50f7e8d06c3768dd97f3@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Dominique Martinet <asmadeus@xxxxxxxxxxxxx> Tested-by: Schspa Shi <schspa@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/9p/trans_fd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -205,6 +205,8 @@ static void p9_conn_cancel(struct p9_con list_move(&req->req_list, &cancel_list); } + spin_unlock(&m->client->lock); + list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) { p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req); list_del(&req->req_list); @@ -212,7 +214,6 @@ static void p9_conn_cancel(struct p9_con req->t_err = err; p9_client_cb(m->client, req, REQ_STATUS_ERROR); } - spin_unlock(&m->client->lock); } static __poll_t
