From: Dan Carpenter dan.carpenter@linaro.org
[ Upstream commit 8fe72b76db79d694858e872370df49676bc3be8c ]
There was a bug where this code forgot to unlock the tdev->mutex if the kzalloc() failed. Fix this issue, by moving the allocation outside the lock.
Fixes: 2d1e952a2b8e ("mailbox: mailbox-test: Fix potential double-free in mbox_test_message_write()") Signed-off-by: Dan Carpenter dan.carpenter@linaro.org Reviewed-by: Lee Jones lee@kernel.org Signed-off-by: Jassi Brar jaswinder.singh@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mailbox/mailbox-test.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/mailbox/mailbox-test.c b/drivers/mailbox/mailbox-test.c index c7ff9653223bf..39236030079e0 100644 --- a/drivers/mailbox/mailbox-test.c +++ b/drivers/mailbox/mailbox-test.c @@ -101,6 +101,7 @@ static ssize_t mbox_test_message_write(struct file *filp, size_t count, loff_t *ppos) { struct mbox_test_device *tdev = filp->private_data; + char *message; void *data; int ret;
@@ -116,12 +117,13 @@ static ssize_t mbox_test_message_write(struct file *filp, return -EINVAL; }
- mutex_lock(&tdev->mutex); - - tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL); - if (!tdev->message) + message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL); + if (!message) return -ENOMEM;
+ mutex_lock(&tdev->mutex); + + tdev->message = message; ret = copy_from_user(tdev->message, userbuf, count); if (ret) { ret = -EFAULT;