| From 1a843639230504609a6d0471c1e37c187be918c6 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 31 Dec 2021 01:47:50 +0300 |
| Subject: i2c: validate user data in compat ioctl |
| |
| From: Pavel Skripkin <paskripkin@gmail.com> |
| |
| [ 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@syzkaller.appspotmail.com |
| Fixes: 7d5cb45655f2 ("i2c compat ioctls: move to ->compat_ioctl()") |
| Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> |
| Signed-off-by: Wolfram Sang <wsa@kernel.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/i2c/i2c-dev.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c |
| index 57aece8098416..140dd074fdee5 100644 |
| --- a/drivers/i2c/i2c-dev.c |
| +++ b/drivers/i2c/i2c-dev.c |
| @@ -544,6 +544,9 @@ 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; |
| |
| -- |
| 2.34.1 |
| |
