Commit 59baeb7a authored Apr 12, 2016 by Jaegeuk Kim Committed by Eric Biggers May 25, 2017

UPSTREAM: ext4/fscrypto: avoid RCU lookup in d_revalidate



commit 03a8bb0e53d9562276045bdfcf2b5de2e4cff5a1 upstream.

As Al pointed, d_revalidate should return RCU lookup before using d_inode.
This was originally introduced by:
commit 34286d66 ("fs: rcu-walk aware d_revalidate method").

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 16fb859f9b2bb246a18b4d0edc605774193c33b7)
Change-Id: Ib3e41f923f02845e0ef78d65706cdc0bde30b9d9
Signed-off-by: Eric Biggers <ebiggers@google.com>

parent d16c842e

fs/ext4/crypto.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -34,6 +34,7 @@
		#include <linux/random.h>
		#include <linux/scatterlist.h>
		#include <linux/spinlock_types.h>
		#include <linux/namei.h>

		#include "ext4_extents.h"
		#include "xattr.h"
		@@ -482,6 +483,9 @@ static int ext4_d_revalidate(struct dentry *dentry, unsigned int flags)
		struct ext4_crypt_info *ci;
		int dir_has_key, cached_with_key;

		if (flags & LOOKUP_RCU)
		return -ECHILD;

		dir = dget_parent(dentry);
		if (!ext4_encrypted_inode(d_inode(dir))) {
		dput(dir);