Commit 71581562 authored by Wolfram Sang's avatar Wolfram Sang Committed by Wolfram Sang
Browse files

i2c: bail out early when RDWR parameters are wrong 



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: default avatar <syzbot+ffb0b3ffa6cfbc7d7b3f@syzkaller.appspotmail.com>
Tested-by: default avatar <syzbot+ffb0b3ffa6cfbc7d7b3f@syzkaller.appspotmail.com>
Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent fd6c3f45

drivers/i2c/i2c-dev.c

+7 −2
Original line number Diff line number Diff line
@@ -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;