File 0012-metadump-Zero-out-unused-portion-of-the-AGFL.patch of Package xfsprogs

From 18cdb6141c404f1a5b36a6447c4f0fb1f0e843dd Mon Sep 17 00:00:00 2001
From: Eric Sandeen <sandeen@sandeen.net>
Date: Thu, 30 Jul 2015 09:17:43 +1000
Subject: [PATCH 12/20] metadump: Zero out unused portion of the AGFL
References: bsc#939367 CVE-2012-2150

mkfs.xfs doesn't zero the AGFL, so if it hasn't been
entirely used, metadump can pick up stale data.  Zero
the unused parts.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Acked-by: Jan Kara <jack@suse.com>

---
 db/metadump.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/db/metadump.c b/db/metadump.c
index cd2edf056ceb..8520f66c1375 100644
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -2099,6 +2099,23 @@ scan_ag(
 		if (stop_on_read_error)
 			goto pop_out;
 	} else {
+		if (agf && zero_stale_data) {
+			/* Zero out unused bits of agfl */
+			int i;
+			 __be32  *agfl_bno;
+
+			agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, iocur_top->bp);
+			i = be32_to_cpu(agf->agf_fllast);
+
+			for (;;) {
+				if (++i == XFS_AGFL_SIZE(mp))
+					i = 0;
+				if (i == be32_to_cpu(agf->agf_flfirst))
+					break;
+				agfl_bno[i] = cpu_to_be32(NULLAGBLOCK);
+			}
+			iocur_top->need_crc = 1;
+		}
 		if (write_buf(iocur_top))
 			goto pop_out;
 	}
-- 
2.1.4