Re: cross memory attach && security check

[Oleg Nesterov <oleg@redhat.com>]

On 01/09, Oleg Nesterov wrote:
>
> Partly I was confused because (I guess) there is another minor bug in
> process_vm_rw(), I think we need
>
> 	--- x/mm/process_vm_access.c
> 	+++ x/mm/process_vm_access.c
> 	@@ -375,10 +375,10 @@ static ssize_t process_vm_rw(pid_t pid,
> 	 
> 		/* Check iovecs */
> 		if (vm_write)
> 	-		rc = rw_copy_check_uvector(WRITE, lvec, liovcnt, UIO_FASTIOV,
> 	+		rc = rw_copy_check_uvector(READ, lvec, liovcnt, UIO_FASTIOV,
> 						   iovstack_l, &iov_l, 1);
> 		else
> 	-		rc = rw_copy_check_uvector(READ, lvec, liovcnt, UIO_FASTIOV,
> 	+		rc = rw_copy_check_uvector(WRITE, lvec, liovcnt, UIO_FASTIOV,
> 						   iovstack_l, &iov_l, 1);

Argh. No, I was wrong, vrfy_dir() swaps READ/WRITE.

Oleg.