linux-kernel - [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: <1303152818-9856-1-git-send-email-khoroshilov@ispras.ru>
Date:	Mon, 18 Apr 2011 22:53:38 +0400
From:	Alexey Khoroshilov <khoroshilov@...ras.ru>
To:	Eric Moore <eric.moore@....com>,
	Kashyap Desai <kashyap.desai@....com>
Cc:	"James E.J. Bottomley" <James.Bottomley@...e.de>,
	linux-scsi@...r.kernel.org, linux-kernel@...r.kernel.org,
	Alexey Khoroshilov <khoroshilov@...ras.ru>
Subject: [PATCH] [SCSI] mpt2sas: fix double mutex lock in NON_BLOCKING state

If mutex_trylock succeed, the control flow goes to mutex_lock_interruptible()
that is not a good thing.

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

Signed-off-by: Alexey Khoroshilov <khoroshilov@...ras.ru>
---
 drivers/scsi/mpt2sas/mpt2sas_ctl.c |   24 ++++++++++++++++--------
 1 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/mpt2sas/mpt2sas_ctl.c b/drivers/scsi/mpt2sas/mpt2sas_ctl.c
index 1c6d2b4..9bd7ffc 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_ctl.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_ctl.c
@@ -648,8 +648,10 @@ _ctl_do_mpt_command(struct MPT2SAS_ADAPTER *ioc,
 
 	issue_reset = 0;
 
-	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;
 
@@ -1587,8 +1589,10 @@ _ctl_diag_register(void __user *arg, enum block_state state)
 	if (_ctl_verify_adapter(karg.hdr.ioc_number, &ioc) == -1 || !ioc)
 		return -ENODEV;
 
-	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;
 	rc = _ctl_diag_register_2(ioc, &karg);
@@ -1932,8 +1936,10 @@ _ctl_diag_release(void __user *arg, enum block_state state)
 		return 0;
 	}
 
-	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;
 
@@ -2033,8 +2039,10 @@ _ctl_diag_read_buffer(void __user *arg, enum block_state state)
 	}
 	/* Get a free request frame and save the message context.
 	*/
-	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;
 
-- 
1.7.1

--
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/