From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Namjae Jeon <namjae.jeon@samsung.com>,
Jeff Layton <jlayton@primarydata.com>,
Steve French <smfrench@gmail.com>,
Sasha Levin <sashal@kernel.org>,
linux-cifs@vger.kernel.org, samba-technical@lists.samba.org
Subject: [PATCH AUTOSEL 4.9 149/251] signal/cifs: Fix cifs_put_tcp_session to call send_sig instead of force_sig
Date: Thu, 16 Jan 2020 12:34:58 -0500 [thread overview]
Message-ID: <20200116173641.22137-109-sashal@kernel.org> (raw)
In-Reply-To: <20200116173641.22137-1-sashal@kernel.org>
From: "Eric W. Biederman" <ebiederm@xmission.com>
[ 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>
---
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 e43ba6db2bdd..110febd69737 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2221,7 +2221,7 @@ 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 *
--
2.20.1
next parent reply other threads:[~2020-01-16 18:07 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200116173641.22137-1-sashal@kernel.org>
2020-01-16 17:34 ` Sasha Levin [this message]
2020-01-16 17:35 ` [PATCH AUTOSEL 4.9 177/251] cifs: fix rmmod regression in cifs.ko caused by force_sig changes Sasha Levin
2020-01-16 19:11 ` [EXTERNAL] " Steven French
2020-01-16 17:35 ` [PATCH AUTOSEL 4.9 183/251] signal: Allow cifs and drbd to receive their terminating signals Sasha Levin
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