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/[email protected]/
Fixes: 1a3e4e94a1b9 ("net: copy from user before calling __get_compat_msghdr")
Reported-by: Marek Szyprowski <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

diff --git a/io_uring/net.c b/io_uring/net.c
index 6b7d5f33e642a0db90a75f892e1a7de3530b0542..e61efa31c729c64b103177b9567f880c4d4272a1 100644 (file)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -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)))
                return -EFAULT;
 
-       ret = __get_compat_msghdr(&iomsg->msg, sr->umsg_compat, &iomsg->uaddr);
+       ret = __get_compat_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
        if (ret)
                return ret;
 

diff --git a/net/compat.c b/net/compat.c
index 513aa9a3fc646626fc3b27a288ccc4ada0cc127d..ed880729d159bd524498a85a16a32d6f38e4f690 100644 (file)
--- a/net/compat.c
+++ b/net/compat.c
@@ -89,7 +89,7 @@ int get_compat_msghdr(struct msghdr *kmsg,
        if (copy_from_user(&msg, umsg, sizeof(*umsg)))
                return -EFAULT;
 
-       err = __get_compat_msghdr(kmsg, umsg, save_addr);
+       err = __get_compat_msghdr(kmsg, &msg, save_addr);
        if (err)
                return err;