Commit 322ee5b3 authored Feb 15, 2008 by Christoph Hellwig Committed by Al Viro Mar 19, 2008

[PATCH] check for null vfsmount in dentry_open()



Make sure no-one calls dentry_open with a NULL vfsmount argument and crap
out with a stacktrace otherwise.  A NULL file->f_vfsmnt has always been
problematic, but with the per-mount r/o tracking we can't accept anymore
at all.

[AV] the last place that passed NULL had been eliminated by the previous
patch (reiserfs xattr stuff)

Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

parent 3227e14c

fs/open.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -903,6 +903,18 @@ struct file dentry_open(struct dentry dentry, struct vfsmount *mnt, int flags)
		int error;
		struct file *f;

		/*
		* We must always pass in a valid mount pointer. Historically
		* callers got away with not passing it, but we must enforce this at
		* the earliest possible point now to avoid strange problems deep in the
		* filesystem stack.
		*/
		if (!mnt) {
		printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__);
		dump_stack();
		return ERR_PTR(-EINVAL);
		}

		error = -ENFILE;
		f = get_empty_filp();
		if (f == NULL) {