From: "Eric W. Biederman" ebiederm@xmission.com
stable inclusion from linux-4.19.99 commit e6a13c753f912564256d81f7036f9c524b1ef8ae bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 ---------------------------
[ Upstream commit 72abe3bcf0911d69b46c1e8bdb5612675e0ac42c ]
The locking in force_sig_info is not prepared to deal with a task that exits or execs (as sighand may change). The is not a locking problem in force_sig as force_sig is only built to handle synchronous exceptions.
Further the function force_sig_info changes the signal state if the signal is ignored, or blocked or if SIGNAL_UNKILLABLE will prevent the delivery of the signal. The signal SIGKILL can not be ignored and can not be blocked and SIGNAL_UNKILLABLE won't prevent it from being delivered.
So using force_sig rather than send_sig for SIGKILL is confusing and pointless.
Because it won't impact the sending of the signal and and because using force_sig is wrong, replace force_sig with send_sig.
Cc: Namjae Jeon namjae.jeon@samsung.com Cc: Jeff Layton jlayton@primarydata.com Cc: Steve French smfrench@gmail.com Fixes: a5c3e1c725af ("Revert "cifs: No need to send SIGKILL to demux_thread during umount"") Fixes: e7ddee9037e7 ("cifs: disable sharing session and tcon and add new TCP sharing code") Signed-off-by: "Eric W. Biederman" ebiederm@xmission.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com [io_uring need allow_kernel_signal] Signed-off-by: yangerkun yangerkun@huawei.com Reviewed-by: zhangyi (F) yi.zhang@huawei.com Signed-off-by: Cheng Jian cj.chengjian@huawei.com --- fs/cifs/connect.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 423bc5b481e4..d4b8f0ecf50a 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2458,7 +2458,7 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
task = xchg(&server->tsk, NULL); if (task) - force_sig(SIGKILL, task); + send_sig(SIGKILL, task, 1); }
static struct TCP_Server_Info *