| Message ID | 20211230224750.15380-1-paskripkin@gmail.com |
|---|---|
| State | Accepted |
| Commit | bb436283e25aaf1533ce061605d23a9564447bdf |
| Headers | show |
| Series | [v3] i2c: validate user data in compat ioctl | expand |
On Fri, Dec 31, 2021 at 01:47:50AM +0300, Pavel Skripkin wrote: > 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@syzkaller.appspotmail.com > Fixes: 7d5cb45655f2 ("i2c compat ioctls: move to ->compat_ioctl()") > Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Applied to for-current, thanks!
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index bce0e8bb7852..cf5d049342ea 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -535,6 +535,9 @@ 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;
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@syzkaller.appspotmail.com Fixes: 7d5cb45655f2 ("i2c compat ioctls: move to ->compat_ioctl()") Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> --- Changes in v3 - Add rdwr_arg.nmsgs == 0 check as Wolfram suggested Changes in v2: - Fixed typos in commit message --- drivers/i2c/i2c-dev.c | 3 +++ 1 file changed, 3 insertions(+)