[PATCH] staging: lirc: fix mismatch in mutex lock-unlock in imon_probe

From: Alexey Khoroshilov
Date: Mon Aug 29 2011 - 16:18:11 EST


If kzalloc failed for allocation of context, goto alloc_status_switch
leads to unlock of unacquired driver_lock. The patch moves
mutex_lock(&driver_lock) before allocation of context.

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

Signed-off-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>
---
drivers/staging/lirc/lirc_imon.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/lirc/lirc_imon.c b/drivers/staging/lirc/lirc_imon.c
index 4a9e563..f5308d5 100644
--- a/drivers/staging/lirc/lirc_imon.c
+++ b/drivers/staging/lirc/lirc_imon.c
@@ -727,6 +727,9 @@ static int imon_probe(struct usb_interface *interface,
int i;
u16 vendor, product;

+ /* prevent races probing devices w/multiple interfaces */
+ mutex_lock(&driver_lock);
+
context = kzalloc(sizeof(struct imon_context), GFP_KERNEL);
if (!context) {
err("%s: kzalloc failed for context", __func__);
@@ -753,9 +756,6 @@ static int imon_probe(struct usb_interface *interface,
dev_dbg(dev, "%s: found iMON device (%04x:%04x, intf%d)\n",
__func__, vendor, product, ifnum);

- /* prevent races probing devices w/multiple interfaces */
- mutex_lock(&driver_lock);
-
/*
* Scan the endpoint list and set:
* first input endpoint = IR endpoint
--
1.7.4.1

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