This is a note to let you know that I've just added the patch titled
i2c: bail out early when RDWR parameters are wrong
to the 5.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
i2c-bail-out-early-when-rdwr-parameters-are-wrong.patch
and it can be found in the queue-5.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9943a3cff7543c3cd279311c1c950a10bafbdc14
Author: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Date: Fri Mar 12 12:57:34 2021 +0100
i2c: bail out early when RDWR parameters are wrong
[ Upstream commit 71581562ee36032d2d574a9b23ad4af6d6a64cf7 ]
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@xxxxxxxxxxxxxxxxxxxxxxxxx
Tested-by: syzbot+ffb0b3ffa6cfbc7d7b3f@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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;
