Messages in this thread Patch in this message | | | From | Pavel Skripkin <> | Subject | [PATCH v3] i2c: validate user data in compat ioctl | Date | Fri, 31 Dec 2021 01:47:50 +0300 |
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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(+)
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; -- 2.34.1
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