Commit 4f6a94d3 authored by Jens Axboe's avatar Jens Axboe
Browse files

net: fix compat pointer in get_compat_msghdr() 

A previous change enabled external users to copy the data before
calling __get_compat_msghdr(), but didn't modify get_compat_msghdr() or
__io_compat_recvmsg_copy_hdr() to take that into account. They are both
stil passing in the __user pointer rather than the copied version.

Ensure we pass in the kernel struct, not the pointer to the user data.

Link: https://lore.kernel.org/all/46439555-644d-08a1-7d66-16f8f9a320f0@samsung.com/


Fixes: 1a3e4e94a1b9 ("net: copy from user before calling __get_compat_msghdr")
Reported-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 48904229

io_uring/net.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -398,7 +398,7 @@ static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req, 
	if (copy_from_user(&msg, sr->umsg_compat, sizeof(msg)))

	if (copy_from_user(&msg, sr->umsg_compat, sizeof(msg)))

		return -EFAULT;

		return -EFAULT;





	ret = __get_compat_msghdr(&iomsg->msg, sr->umsg_compat, &iomsg->uaddr);

	ret = __get_compat_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);

	if (ret)

	if (ret)

		return ret;

		return ret;

net/compat.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -89,7 +89,7 @@ int get_compat_msghdr(struct msghdr *kmsg, 
	if (copy_from_user(&msg, umsg, sizeof(*umsg)))

	if (copy_from_user(&msg, umsg, sizeof(*umsg)))

		return -EFAULT;

		return -EFAULT;





	err = __get_compat_msghdr(kmsg, umsg, save_addr);

	err = __get_compat_msghdr(kmsg, &msg, save_addr);

	if (err)

	if (err)

		return err;

		return err;