diff mbox series

i2c: bail out early when RDWR parameters are wrong

Message ID 20210312115734.14022-1-wsa+renesas@sang-engineering.com
State Accepted
Commit 71581562ee36032d2d574a9b23ad4af6d6a64cf7
Headers show
Series i2c: bail out early when RDWR parameters are wrong | expand

Commit Message

Wolfram Sang March 12, 2021, 11:57 a.m. UTC 
The buggy parameters currently get caught later, but emit a noisy WARN.
Userspace should not be able to trigger this, so add similar checks much
earlier. Also avoids some unneeded code paths, of course. Apply kernel
coding stlye to a comment while here.

Reported-by: syzbot+ffb0b3ffa6cfbc7d7b3f@syzkaller.appspotmail.com
Tested-by: syzbot+ffb0b3ffa6cfbc7d7b3f@syzkaller.appspotmail.com
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/i2c/i2c-dev.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

Comments

Wolfram Sang March 18, 2021, 11:15 a.m. UTC | #1 
On Fri, Mar 12, 2021 at 12:57:34PM +0100, Wolfram Sang wrote:
> The buggy parameters currently get caught later, but emit a noisy WARN.

> Userspace should not be able to trigger this, so add similar checks much

> earlier. Also avoids some unneeded code paths, of course. Apply kernel

> coding stlye to a comment while here.

> 

> Reported-by: syzbot+ffb0b3ffa6cfbc7d7b3f@syzkaller.appspotmail.com

> Tested-by: syzbot+ffb0b3ffa6cfbc7d7b3f@syzkaller.appspotmail.com

> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>


Applied to for-next, thanks!
diff mbox series

Patch

diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index 6ceb11cc4be1..6ef38a8ee95c 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -440,8 +440,13 @@  static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 				   sizeof(rdwr_arg)))
 			return -EFAULT;
 
-		/* Put an arbitrary limit on the number of messages that can
-		 * be sent at once */
+		if (!rdwr_arg.msgs || rdwr_arg.nmsgs == 0)
+			return -EINVAL;
+
+		/*
+		 * Put an arbitrary limit on the number of messages that can
+		 * be sent at once
+		 */
 		if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS)
 			return -EINVAL;