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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        "Darrick J. Wong" <darrick.wong@oracle.com>,
        Brian Foster <bfoster@redhat.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 67/80] xfs: fix partially uninitialized structure in xfs_reflink_remap_extent
Date:   Fri,  1 May 2020 15:22:01 +0200
Message-Id: <20200501131534.974029037@linuxfoundation.org>
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From: Darrick J. Wong <darrick.wong@oracle.com>

[ Upstream commit c142932c29e533ee892f87b44d8abc5719edceec ]

In the reflink extent remap function, it turns out that uirec (the block
mapping corresponding only to the part of the passed-in mapping that got
unmapped) was not fully initialized.  Specifically, br_state was not
being copied from the passed-in struct to the uirec.  This could lead to
unpredictable results such as the reflinked mapping being marked
unwritten in the destination file.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/xfs/xfs_reflink.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 17d3c964a2a23..6b753b969f7b8 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1162,6 +1162,7 @@ xfs_reflink_remap_extent(
 		uirec.br_startblock = irec->br_startblock + rlen;
 		uirec.br_startoff = irec->br_startoff + rlen;
 		uirec.br_blockcount = unmap_len - rlen;
+		uirec.br_state = irec->br_state;
 		unmap_len = rlen;
 
 		/* If this isn't a real mapping, we're done. */
-- 
2.20.1