Commit 035ff33c authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

fuse: write inode in fuse_release() 



A race between write(2) and close(2) allows pages to be dirtied after
fuse_flush -> write_inode_now().  If these pages are not flushed from
fuse_release(), then there might not be a writable open file later.  So any
remaining dirty pages must be written back before the file is released.

This is a partial revert of the blamed commit.

Reported-by: default avatar <syzbot+6e1efbd8efaaa6860e91@syzkaller.appspotmail.com>
Fixes: 36ea2337 ("fuse: write inode in fuse_vma_close() instead of fuse_release()")
Cc: <stable@vger.kernel.org> # v5.16
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent f2906aa8

fs/fuse/file.c

+9 −0
Original line number Diff line number Diff line
@@ -338,6 +338,15 @@ static int fuse_open(struct inode *inode, struct file *file) 


static int fuse_release(struct inode *inode, struct file *file)

{

	struct fuse_conn *fc = get_fuse_conn(inode);



	/*

	 * Dirty pages might remain despite write_inode_now() call from

	 * fuse_flush() due to writes racing with the close.

	 */

	if (fc->writeback_cache)

		write_inode_now(inode, 1);



	fuse_release_common(file, false);



	/* return value is ignored by VFS */