linux-kernel - [PATCH 008/270] eCryptfs: Write out all dirty pages just before releasing the lower file

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1353949160-26803-9-git-send-email-herton.krzesinski@canonical.com>
Date:	Mon, 26 Nov 2012 14:54:58 -0200
From:	Herton Ronaldo Krzesinski <herton.krzesinski@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Tyler Hicks <tyhicks@...onical.com>,
	Herton Ronaldo Krzesinski <herton.krzesinski@...onical.com>
Subject: [PATCH 008/270] eCryptfs: Write out all dirty pages just before releasing the lower file

3.5.7u1 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tyler Hicks <tyhicks@...onical.com>

commit 7149f2558d5b5b988726662fe58b1c388337805b upstream.

Fixes a regression caused by:

821f749 eCryptfs: Revert to a writethrough cache model

That patch reverted some code (specifically, 32001d6f) that was
necessary to properly handle open() -> mmap() -> close() -> dirty pages
-> munmap(), because the lower file could be closed before the dirty
pages are written out.

Rather than reapplying 32001d6f, this approach is a better way of
ensuring that the lower file is still open in order to handle writing
out the dirty pages. It is called from ecryptfs_release(), while we have
a lock on the lower file pointer, just before the lower file gets the
final fput() and we overwrite the pointer.

https://launchpad.net/bugs/1047261

Signed-off-by: Tyler Hicks <tyhicks@...onical.com>
Reported-by: Artemy Tregubenko <me@...y.name>
Tested-by: Artemy Tregubenko <me@...y.name>
Tested-by: Colin Ian King <colin.king@...onical.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@...onical.com>
---
 fs/ecryptfs/main.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index df217dc..c2a9c39 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -162,6 +162,7 @@ void ecryptfs_put_lower_file(struct inode *inode)
 	inode_info = ecryptfs_inode_to_private(inode);
 	if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count,
 				      &inode_info->lower_file_mutex)) {
+		filemap_write_and_wait(inode->i_mapping);
 		fput(inode_info->lower_file);
 		inode_info->lower_file = NULL;
 		mutex_unlock(&inode_info->lower_file_mutex);
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/