linux-kernel - [PATCH] [96/223] TTY: ldisc, fix open flag handling

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 13 Dec 2010 00:46:36 +0100 (CET)
From:	Andi Kleen <andi@...stfloor.org>
To:	jslaby@...e.cz, alan@...ux.intel.com, slapin@...fans.org,
	gregkh@...e.de, ak@...ux.intel.com, linux-kernel@...r.kernel.org,
	stable@...nel.org
Subject: [PATCH] [96/223] TTY: ldisc, fix open flag handling

2.6.35-longterm review patch.  If anyone has any objections, please let me know.

------------------
From: Jiri Slaby <jslaby@...e.cz>

commit 7f90cfc505d613f4faf096e0d84ffe99208057d9 upstream.

When a concrete ldisc open fails in tty_ldisc_open, we forget to clear
TTY_LDISC_OPEN. This causes a false warning on the next ldisc open:
WARNING: at drivers/char/tty_ldisc.c:445 tty_ldisc_open+0x26/0x38()
Hardware name: System Product Name
Modules linked in: ...
Pid: 5251, comm: a.out Tainted: G        W  2.6.32-5-686 #1
Call Trace:
 [<c1030321>] ? warn_slowpath_common+0x5e/0x8a
 [<c1030357>] ? warn_slowpath_null+0xa/0xc
 [<c119311c>] ? tty_ldisc_open+0x26/0x38
 [<c11936c5>] ? tty_set_ldisc+0x218/0x304
...

So clear the bit when failing...

Introduced in c65c9bc3efa (tty: rewrite the ldisc locking) back in
2.6.31-rc1.

Signed-off-by: Jiri Slaby <jslaby@...e.cz>
Cc: Alan Cox <alan@...ux.intel.com>
Reported-by: Sergey Lapin <slapin@...fans.org>
Tested-by: Sergey Lapin <slapin@...fans.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>
Signed-off-by: Andi Kleen <ak@...ux.intel.com>

---
 drivers/char/tty_ldisc.c |    2 ++
 1 file changed, 2 insertions(+)

Index: linux/drivers/char/tty_ldisc.c
===================================================================
--- linux.orig/drivers/char/tty_ldisc.c
+++ linux/drivers/char/tty_ldisc.c
@@ -452,6 +452,8 @@ static int tty_ldisc_open(struct tty_str
                 /* BKL here locks verus a hangup event */
 		lock_kernel();
 		ret = ld->ops->open(tty);
+		if (ret)
+			clear_bit(TTY_LDISC_OPEN, &tty->flags);
 		unlock_kernel();
 		return ret;
 	}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/