Commit 1d6e65be authored May 07, 2018 by NeilBrown Committed by Greg Kroah-Hartman May 08, 2018

staging: lustre: fix error deref in ll_splice_alias().



d_splice_alias() can return an ERR_PTR().
If it does while debugging is enabled, the following
CDEBUG() will dereference that error and crash.

So add appropriate checking, and provide a separate
debug message for the error case.

Reported-and-tested-by: James Simmons <jsimmons@infradead.org>
Fixes: e9d4f0b9 ("staging: lustre: llite: use d_splice_alias for directories.")
Reviewed-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 9604c7ac

drivers/staging/lustre/lustre/llite/namei.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -442,9 +442,14 @@ struct dentry ll_splice_alias(struct inode inode, struct dentry *de)
		} else {
		struct dentry *new = d_splice_alias(inode, de);

		if (IS_ERR(new))
		CDEBUG(D_DENTRY,
		"splice inode %p as %pd gives error %lu\n",
		inode, de, PTR_ERR(new));
		if (new)
		de = new;
		}
		if (!IS_ERR(de))
		CDEBUG(D_DENTRY, "Add dentry %p inode %p refc %d flags %#x\n",
		de, d_inode(de), d_count(de), de->d_flags);
		return de;