linux-kernel - [PATCH 4.4 013/105] ext4: update mtime in ext4_punch

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-Id: <20180701153150.412482422@linuxfoundation.org>
Date:   Sun,  1 Jul 2018 18:01:23 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Lukas Czerner <lczerner@...hat.com>,
        Theodore Tso <tytso@....edu>,
        Joe Habermann <joe.habermann@...ntum.com>
Subject: [PATCH 4.4 013/105] ext4: update mtime in ext4_punch_hole even if no blocks are released

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

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

From: Lukas Czerner <lczerner@...hat.com>

commit eee597ac931305eff3d3fd1d61d6aae553bc0984 upstream.

Currently in ext4_punch_hole we're going to skip the mtime update if
there are no actual blocks to release. However we've actually modified
the file by zeroing the partial block so the mtime should be updated.

Moreover the sync and datasync handling is skipped as well, which is
also wrong. Fix it.

Signed-off-by: Lukas Czerner <lczerner@...hat.com>
Signed-off-by: Theodore Ts'o <tytso@....edu>
Reported-by: Joe Habermann <joe.habermann@...ntum.com>
Cc: <stable@...r.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 fs/ext4/inode.c |   40 ++++++++++++++++++++--------------------
 1 file changed, 20 insertions(+), 20 deletions(-)

--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3787,28 +3787,28 @@ int ext4_punch_hole(struct inode *inode,
 		EXT4_BLOCK_SIZE_BITS(sb);
 	stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
 
-	/* If there are no blocks to remove, return now */
-	if (first_block >= stop_block)
-		goto out_stop;
-
-	down_write(&EXT4_I(inode)->i_data_sem);
-	ext4_discard_preallocations(inode);
-
-	ret = ext4_es_remove_extent(inode, first_block,
-				    stop_block - first_block);
-	if (ret) {
-		up_write(&EXT4_I(inode)->i_data_sem);
-		goto out_stop;
-	}
+	/* If there are blocks to remove, do it */
+	if (stop_block > first_block) {
+
+		down_write(&EXT4_I(inode)->i_data_sem);
+		ext4_discard_preallocations(inode);
 
-	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
-		ret = ext4_ext_remove_space(inode, first_block,
-					    stop_block - 1);
-	else
-		ret = ext4_ind_remove_space(handle, inode, first_block,
-					    stop_block);
+		ret = ext4_es_remove_extent(inode, first_block,
+					    stop_block - first_block);
+		if (ret) {
+			up_write(&EXT4_I(inode)->i_data_sem);
+			goto out_stop;
+		}
+
+		if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+			ret = ext4_ext_remove_space(inode, first_block,
+						    stop_block - 1);
+		else
+			ret = ext4_ind_remove_space(handle, inode, first_block,
+						    stop_block);
 
-	up_write(&EXT4_I(inode)->i_data_sem);
+		up_write(&EXT4_I(inode)->i_data_sem);
+	}
 	if (IS_SYNC(inode))
 		ext4_handle_sync(handle);