Re: [syzbot] [ntfs3?] KASAN: slab-use-after-free Read in chrdev_open

[Hillf Danton]

On Fri, 26 Apr 2024 05:00:21 -0700
> syzbot found the following issue on:
> 
> HEAD commit:    e33c4963bf53 Merge tag 'nfsd-6.9-5' of git://git.kernel.or..
> git tree:       upstream
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12499380980000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git  e33c4963bf53

--- x/fs/open.c
+++ y/fs/open.c
@@ -952,7 +952,9 @@ static int do_dentry_open(struct file *f
 	if (!open)
 		open = f->f_op->open;
 	if (open) {
+		ihold(inode);
 		error = open(inode, f);
+		iput(inode);
 		if (error)
 			goto cleanup_all;
 	}
--