linux-kernel - [RESEND PATCH] [SCSI] mpt2sas: fix double mutex lock in NON

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>] [day] [month] [year] [list]

Message-Id: <1345828479-30231-1-git-send-email-khoroshilov@ispras.ru>
Date:	Fri, 24 Aug 2012 21:14:38 +0400
From:	Alexey Khoroshilov <khoroshilov@...ras.ru>
To:	"James E.J. Bottomley" <JBottomley@...allels.com>
Cc:	Alexey Khoroshilov <khoroshilov@...ras.ru>,
	linux-scsi@...r.kernel.org,
	Nagalakshmi Nandigama <nagalakshmi.nandigama@....com>,
	linux-kernel@...r.kernel.org, ldv-project@...ras.ru
Subject: [RESEND PATCH] [SCSI] mpt2sas: fix double mutex lock in NON_BLOCKING state

If state is NON_BLOCKING and mutex_trylock is succeed,
the control flow goes to mutex_lock_interruptible() that is a deadlock.

Found by Linux Driver Verification project (linuxtesting.org).

Acked-by: "Nandigama, Nagalakshmi" <Nagalakshmi.Nandigama@....com>
Signed-off-by: Alexey Khoroshilov <khoroshilov@...ras.ru>
---
 drivers/scsi/mpt2sas/mpt2sas_ctl.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/mpt2sas/mpt2sas_ctl.c b/drivers/scsi/mpt2sas/mpt2sas_ctl.c
index 49bdd2d..d29ea56 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_ctl.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_ctl.c
@@ -2181,8 +2181,10 @@ _ctl_ioctl_main(struct file *file, unsigned int cmd, void __user *arg,
 		return -EAGAIN;
 
 	state = (file->f_flags & O_NONBLOCK) ? NON_BLOCKING : BLOCKING;
-	if (state == NON_BLOCKING && !mutex_trylock(&ioc->ctl_cmds.mutex))
-		return -EAGAIN;
+	if (state == NON_BLOCKING) {
+		if (!mutex_trylock(&ioc->ctl_cmds.mutex))
+			return -EAGAIN;
+	}
 	else if (mutex_lock_interruptible(&ioc->ctl_cmds.mutex))
 		return -ERESTARTSYS;
 
-- 
1.7.9.5

--
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/