This is a note to let you know that I've just added the patch titled
i2c: validate user data in compat ioctl
to the 5.10-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-validate-user-data-in-compat-ioctl.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9fb1f45e73711a5af33f50bff89d2f3aeaea072a
Author: Pavel Skripkin <paskripkin@xxxxxxxxx>
Date: Fri Dec 31 01:47:50 2021 +0300
i2c: validate user data in compat ioctl
[ Upstream commit bb436283e25aaf1533ce061605d23a9564447bdf ]
Wrong user data may cause warning in i2c_transfer(), ex: zero msgs.
Userspace should not be able to trigger warnings, so this patch adds
validation checks for user data in compact ioctl to prevent reported
warnings
Reported-and-tested-by: syzbot+e417648b303855b91d8a@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 7d5cb45655f2 ("i2c compat ioctls: move to ->compat_ioctl()")
Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx>
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 f358120d59b38..dafad891998ec 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -536,6 +536,9 @@ static long compat_i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned lo
sizeof(rdwr_arg)))
return -EFAULT;
+ if (!rdwr_arg.msgs || rdwr_arg.nmsgs == 0)
+ return -EINVAL;
+
if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS)
return -EINVAL;
