Commit 40a19260 authored by Al Viro's avatar Al Viro
Browse files

fix the breakage in close_fd_get_file() calling conventions change 



It used to grab an extra reference to struct file rather than
just transferring to caller the one it had removed from descriptor
table.  New variant doesn't, and callers need to be adjusted.

Reported-and-tested-by: default avatar <syzbot+47dd250f527cb7bebf24@syzkaller.appspotmail.com>
Fixes: 6319194e ("Unify the primitives for file descriptor closing")
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 6319194e

drivers/android/binder.c

+2 −0
Original line number Diff line number Diff line
@@ -1857,6 +1857,8 @@ static void binder_deferred_fd_close(int fd) 
	init_task_work(&twcb->twork, binder_do_fd_close);

	twcb->file = close_fd_get_file(fd);

	if (twcb->file) {

		// pin it until binder_do_fd_close(); see comments there

		get_file(twcb->file);

		filp_close(twcb->file, current->files);

		task_work_add(current, &twcb->twork, TWA_RESUME);

	} else {

fs/file.c

+1 −2
Original line number Diff line number Diff line
@@ -800,8 +800,7 @@ struct file *__close_fd_get_file(unsigned int fd) 


/*

 * variant of close_fd that gets a ref on the file for later fput.

 * The caller must ensure that filp_close() called on the file, and then

 * an fput().

 * The caller must ensure that filp_close() called on the file.

 */

struct file *close_fd_get_file(unsigned int fd)

{

fs/io_uring.c

+1 −4
Original line number Diff line number Diff line
@@ -5110,7 +5110,7 @@ static int io_close(struct io_kiocb *req, unsigned int issue_flags) 
	struct files_struct *files = current->files;

	struct io_close *close = &req->close;

	struct fdtable *fdt;

	struct file *file = NULL;

	struct file *file;

	int ret = -EBADF;



	if (req->close.file_slot) {
@@ -5127,7 +5127,6 @@ static int io_close(struct io_kiocb *req, unsigned int issue_flags) 
	file = fdt->fd[close->fd];

	if (!file || file->f_op == &io_uring_fops) {

		spin_unlock(&files->file_lock);

		file = NULL;

		goto err;

	}
@@ -5147,8 +5146,6 @@ static int io_close(struct io_kiocb *req, unsigned int issue_flags) 
err:

	if (ret < 0)

		req_set_fail(req);

	if (file)

		fput(file);

	__io_req_complete(req, issue_flags, ret, 0);

	return 0;

}