From: Philipp Stanner pstanner@redhat.com

[ Upstream commit cc9c54232f04aef3a5d7f64a0ece7df00f1aaa3d ]

i2c-dev.c utilizes memdup_user() to copy a userspace array. This is done without an overflow check.

Use the new wrapper memdup_array_user() to copy the array more safely.

Suggested-by: Dave Airlie airlied@redhat.com Signed-off-by: Philipp Stanner pstanner@redhat.com Signed-off-by: Wolfram Sang wsa@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/i2c/i2c-dev.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index 7da6ca26a5f56..5669c8b56b264 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -451,8 +451,8 @@ static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) return -EINVAL;

- rdwr_pa = memdup_user(rdwr_arg.msgs, - rdwr_arg.nmsgs * sizeof(struct i2c_msg)); + rdwr_pa = memdup_array_user(rdwr_arg.msgs, + rdwr_arg.nmsgs, sizeof(struct i2c_msg)); if (IS_ERR(rdwr_pa)) return PTR_ERR(rdwr_pa);