From: daniel.starke@siemens.com
To: linux-serial@vger.kernel.org, gregkh@linuxfoundation.org,
jirislaby@kernel.org
Cc: linux-kernel@vger.kernel.org, Daniel Starke <daniel.starke@siemens.com>
Subject: [PATCH 1/1] tty: n_gsm: fix proper link termination after failed open
Date: Thu, 17 Feb 2022 00:05:51 -0800 [thread overview]
Message-ID: <20220217080555.5387-3-daniel.starke@siemens.com> (raw)
In-Reply-To: <20220217080555.5387-1-daniel.starke@siemens.com>
Trying to open a DLCI by sending a SABM frame may fail with a timeout.
The link is closed on the initiator side without informing the responder
about this event. The responder assumes the link is open after sending a
UA frame to answer the SABM frame. The link gets stuck in a half open
state.
This patch fixes this by initiating the proper link termination procedure
after link setup timeout instead of silently closing it down.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
---
drivers/tty/n_gsm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 0b1808e3a912..52224a3494a0 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1514,7 +1514,7 @@ static void gsm_dlci_t1(struct timer_list *t)
dlci->mode = DLCI_MODE_ADM;
gsm_dlci_open(dlci);
} else {
- gsm_dlci_close(dlci);
+ gsm_dlci_begin_close(dlci); /* prevent half open link */
}
break;
--
2.25.1
next prev parent reply other threads:[~2022-02-17 8:07 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-17 8:05 [PATCH 1/1] tty: n_gsm: fix encoding of control signal octet bit DV daniel.starke
2022-02-17 8:05 ` [PATCH 1/1] tty: n_gsm: fix encoding of command/response bit daniel.starke
2022-02-17 8:05 ` daniel.starke [this message]
2022-02-17 8:05 ` [PATCH 1/1] tty: n_gsm: fix NULL pointer access due to DLCI release daniel.starke
2022-02-17 8:05 ` [PATCH 1/1] tty: n_gsm: fix wrong tty control line for flow control daniel.starke
2022-02-17 8:05 ` [PATCH 1/1] tty: n_gsm: fix wrong modem processing in convergence layer type 2 daniel.starke
2022-02-17 8:05 ` [PATCH 1/1] tty: n_gsm: fix deadlock in gsmtty_open() daniel.starke
2022-02-17 9:56 ` [PATCH 1/1] tty: n_gsm: fix encoding of control signal octet bit DV Greg KH
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