linux-kernel - [PATCH] eCryptfs: Protect crypt_stat->flags in ecryptfs

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Message-ID: <20080422154117.GB8034@localhost.austin.ibm.com>
Date:	Tue, 22 Apr 2008 10:41:17 -0500
From:	Michael Halcrow <mhalcrow@...ibm.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Al Viro <viro@...IV.linux.org.uk>
Subject: [PATCH] eCryptfs: Protect crypt_stat->flags in ecryptfs_open()

Al Viro wrote:
> 	Incidentally, looking at ecryptfs open(), WTF is protecting
> crypt_stat->flags?  We take crypt_stat->cs_mutex, do nothing but
> check-and-modify of ->flags under it, then drop and several lines
> later do crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); with no
> ->cs_mutex held...

Make sure crypt_stat->flags is protected with a lock in
ecryptfs_open().

Signed-off-by: Michael Halcrow <mhalcrow@...ibm.com>
---
 fs/ecryptfs/file.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 2b8f5ed..2258b8f 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -195,7 +195,9 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 		file, ecryptfs_inode_to_private(inode)->lower_file);
 	if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
 		ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
+		mutex_lock(&crypt_stat->cs_mutex);
 		crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
+		mutex_unlock(&crypt_stat->cs_mutex);
 		rc = 0;
 		goto out;
 	}
-- 
1.5.1.6

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