This is a note to let you know that I've just added the patch titled
TTY: n_gsm, fix false positive WARN_ON
to the 4.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tty-n_gsm-fix-false-positive-warn_on.patch
and it can be found in the queue-4.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d175feca89a1c162f60f4e3560ca7bc9437c65eb Mon Sep 17 00:00:00 2001
From: Jiri Slaby <jslaby@xxxxxxx>
Date: Tue, 22 Mar 2016 18:09:51 +0100
Subject: TTY: n_gsm, fix false positive WARN_ON
From: Jiri Slaby <jslaby@xxxxxxx>
commit d175feca89a1c162f60f4e3560ca7bc9437c65eb upstream.
Dmitry reported, that the current cleanup code in n_gsm can trigger a
warning:
WARNING: CPU: 2 PID: 24238 at drivers/tty/n_gsm.c:2048 gsm_cleanup_mux+0x166/0x6b0()
...
Call Trace:
...
[<ffffffff81247ab9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:490
[<ffffffff828d0456>] gsm_cleanup_mux+0x166/0x6b0 drivers/tty/n_gsm.c:2048
[<ffffffff828d4d87>] gsmld_open+0x5b7/0x7a0 drivers/tty/n_gsm.c:2386
[<ffffffff828b9078>] tty_ldisc_open.isra.2+0x78/0xd0 drivers/tty/tty_ldisc.c:447
[<ffffffff828b973a>] tty_set_ldisc+0x1ca/0xa70 drivers/tty/tty_ldisc.c:567
[< inline >] tiocsetd drivers/tty/tty_io.c:2650
[<ffffffff828a14ea>] tty_ioctl+0xb2a/0x2140 drivers/tty/tty_io.c:2883
...
But this is a legal path when open fails to find a space in the
gsm_mux array and tries to clean up. So make it a standard test
instead of a warning.
Reported-by: "Dmitry Vyukov" <dvyukov@xxxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/CACT4Y+bHQbAB68VFi7Romcs-Z9ZW3kQRvcq+BvHH1oa5NcAdLA@xxxxxxxxxxxxxx
Fixes: 5a640967 ("tty/n_gsm.c: fix a memory leak in gsmld_open()")
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/n_gsm.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2045,7 +2045,9 @@ static void gsm_cleanup_mux(struct gsm_m
}
}
spin_unlock(&gsm_mux_lock);
- WARN_ON(i == MAX_MUX);
+ /* open failed before registering => nothing to do */
+ if (i == MAX_MUX)
+ return;
/* In theory disconnecting DLCI 0 is sufficient but for some
modems this is apparently not the case. */
Patches currently in stable-queue which might be from jslaby@xxxxxxx are
queue-4.6/bluetooth-vhci-purge-unhandled-skbs.patch
queue-4.6/tty-n_gsm-fix-false-positive-warn_on.patch
queue-4.6/bluetooth-vhci-fix-open_timeout-vs.-hdev-race.patch
queue-4.6/tty-vt-return-error-when-con_startup-fails.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html