media: lirc: do not pass ERR_PTR to kfree

If memdup_user() fails, txbuf will be an error pointer and passed
to kfree.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c
index 6cedb54..8618aba 100644 (file)
--- a/drivers/media/rc/lirc_dev.c
+++ b/drivers/media/rc/lirc_dev.c
@@ -231,7 +231,7 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 {
        struct lirc_fh *fh = file->private_data;
        struct rc_dev *dev = fh->rc;
-       unsigned int *txbuf = NULL;
+       unsigned int *txbuf;
        struct ir_raw_event *raw = NULL;
        ssize_t ret;
        size_t count;
@@ -246,14 +246,14 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 
        if (!dev->registered) {
                ret = -ENODEV;
-               goto out;
+               goto out_unlock;
        }
 
        start = ktime_get();
 
        if (!dev->tx_ir) {
                ret = -EINVAL;
-               goto out;
+               goto out_unlock;
        }
 
        if (fh->send_mode == LIRC_MODE_SCANCODE) {
@@ -261,17 +261,17 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 
                if (n != sizeof(scan)) {
                        ret = -EINVAL;
-                       goto out;
+                       goto out_unlock;
                }
 
                if (copy_from_user(&scan, buf, sizeof(scan))) {
                        ret = -EFAULT;
-                       goto out;
+                       goto out_unlock;
                }
 
                if (scan.flags || scan.keycode || scan.timestamp) {
                        ret = -EINVAL;
-                       goto out;
+                       goto out_unlock;
                }
 
                /*
@@ -283,26 +283,26 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
                if (scan.scancode > U32_MAX ||
                    !rc_validate_scancode(scan.rc_proto, scan.scancode)) {
                        ret = -EINVAL;
-                       goto out;
+                       goto out_unlock;
                }
 
                raw = kmalloc_array(LIRCBUF_SIZE, sizeof(*raw), GFP_KERNEL);
                if (!raw) {
                        ret = -ENOMEM;
-                       goto out;
+                       goto out_unlock;
                }
 
                ret = ir_raw_encode_scancode(scan.rc_proto, scan.scancode,
                                             raw, LIRCBUF_SIZE);
                if (ret < 0)
-                       goto out;
+                       goto out_kfree;
 
                count = ret;
 
                txbuf = kmalloc_array(count, sizeof(unsigned int), GFP_KERNEL);
                if (!txbuf) {
                        ret = -ENOMEM;
-                       goto out;
+                       goto out_kfree;
                }
 
                for (i = 0; i < count; i++)
@@ -318,26 +318,26 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
        } else {
                if (n < sizeof(unsigned int) || n % sizeof(unsigned int)) {
                        ret = -EINVAL;
-                       goto out;
+                       goto out_unlock;
                }
 
                count = n / sizeof(unsigned int);
                if (count > LIRCBUF_SIZE || count % 2 == 0) {
                        ret = -EINVAL;
-                       goto out;
+                       goto out_unlock;
                }
 
                txbuf = memdup_user(buf, n);
                if (IS_ERR(txbuf)) {
                        ret = PTR_ERR(txbuf);
-                       goto out;
+                       goto out_unlock;
                }
        }
 
        for (i = 0; i < count; i++) {
                if (txbuf[i] > IR_MAX_DURATION / 1000 - duration || !txbuf[i]) {
                        ret = -EINVAL;
-                       goto out;
+                       goto out_kfree;
                }
 
                duration += txbuf[i];
@@ -345,7 +345,7 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 
        ret = dev->tx_ir(dev, txbuf, count);
        if (ret < 0)
-               goto out;
+               goto out_kfree;
 
        if (fh->send_mode == LIRC_MODE_SCANCODE) {
                ret = n;
@@ -368,10 +368,11 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
                schedule_timeout(usecs_to_jiffies(towait));
        }
 
-out:
-       mutex_unlock(&dev->lock);
+out_kfree:
        kfree(txbuf);
        kfree(raw);
+out_unlock:
+       mutex_unlock(&dev->lock);
        return ret;
 }