Patch "ocfs2: fix shift left overflow" has been added to the 4.1-stable tree

Patch "ocfs2: fix shift left overflow" has been added to the 4.1-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    ocfs2: fix shift left overflow

to the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ocfs2-fix-shift-left-overflow.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 32e5a2a2be6b085febaac36efff495ad65a55e6c Mon Sep 17 00:00:00 2001
From: Joseph Qi <joseph.qi@huawei.com>
Date: Thu, 6 Aug 2015 15:46:48 -0700
Subject: ocfs2: fix shift left overflow

From: Joseph Qi <joseph.qi@huawei.com>

commit 32e5a2a2be6b085febaac36efff495ad65a55e6c upstream.

When using a large volume, for example 9T volume with 2T already used,
frequent creation of small files with O_DIRECT when the IO is not
cluster aligned may clear sectors in the wrong place.  This will cause
filesystem corruption.

This is because p_cpos is a u32.  When calculating the corresponding
sector it should be converted to u64 first, otherwise it may overflow.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/ocfs2/aops.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -686,7 +686,7 @@ static int ocfs2_direct_IO_zero_extend(s
 
 	if (p_cpos && !(ext_flags & OCFS2_EXT_UNWRITTEN)) {
 		u64 s = i_size_read(inode);
-		sector_t sector = (p_cpos << (osb->s_clustersize_bits - 9)) +
+		sector_t sector = ((u64)p_cpos << (osb->s_clustersize_bits - 9)) +
 			(do_div(s, osb->s_clustersize) >> 9);
 
 		ret = blkdev_issue_zeroout(osb->sb->s_bdev, sector,
@@ -911,7 +911,7 @@ static ssize_t ocfs2_direct_IO_write(str
 		BUG_ON(!p_cpos || (ext_flags & OCFS2_EXT_UNWRITTEN));
 
 		ret = blkdev_issue_zeroout(osb->sb->s_bdev,
-				p_cpos << (osb->s_clustersize_bits - 9),
+				(u64)p_cpos << (osb->s_clustersize_bits - 9),
 				zero_len_head >> 9, GFP_NOFS, false);
 		if (ret < 0)
 			mlog_errno(ret);


Patches currently in stable-queue which might be from joseph.qi@huawei.com are

queue-4.1/ocfs2-fix-bug-in-ocfs2_downconvert_thread_do_work.patch
queue-4.1/ocfs2-fix-shift-left-overflow.patch