Merge tag 'io_uring-5.6-20200320' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "Two different fixes in here:

   - Fix for a potential NULL pointer deref for links with async or
     drain marked (Pavel)

   - Fix for not properly checking RLIMIT_NOFILE for async punted
     operations.

     This affects openat/openat2, which were added this cycle, and
     accept4. I did a full audit of other cases where we might check
     current->signal->rlim[] and found only RLIMIT_FSIZE for buffered
     writes and fallocate. That one is fixed and queued for 5.7 and
     marked stable"

* tag 'io_uring-5.6-20200320' of git://git.kernel.dk/linux-block:
  io_uring: make sure accept honor rlimit nofile
  io_uring: make sure openat/openat2 honor rlimit nofile
  io_uring: NULL-deref for IOSQE_{ASYNC,DRAIN}

1 files changed, 5 insertions, 3 deletions

diff --git a/net/socket.c b/net/socket.c
index b79a05de7c6e..2eecf1517f76 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1707,7 +1707,8 @@ SYSCALL_DEFINE2(listen, int, fd, int, backlog)
 
 int __sys_accept4_file(struct file *file, unsigned file_flags,
 		       struct sockaddr __user *upeer_sockaddr,
-		       int __user *upeer_addrlen, int flags)
+		       int __user *upeer_addrlen, int flags,
+		       unsigned long nofile)
 {
 	struct socket *sock, *newsock;
 	struct file *newfile;
@@ -1738,7 +1739,7 @@ int __sys_accept4_file(struct file *file, unsigned file_flags,
 	 */
 	__module_get(newsock->ops->owner);
 
-	newfd = get_unused_fd_flags(flags);
+	newfd = __get_unused_fd_flags(flags, nofile);
 	if (unlikely(newfd < 0)) {
 		err = newfd;
 		sock_release(newsock);
@@ -1807,7 +1808,8 @@ int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
 	f = fdget(fd);
 	if (f.file) {
 		ret = __sys_accept4_file(f.file, 0, upeer_sockaddr,
-						upeer_addrlen, flags);
+						upeer_addrlen, flags,
+						rlimit(RLIMIT_NOFILE));
 		if (f.flags)
 			fput(f.file);
 	}