This is a note to let you know that I've just added the patch titled
xfs: growfs overruns AGFL buffer on V4 filesystems
to the 3.12-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:
xfs-growfs-overruns-agfl-buffer-on-v4-filesystems.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f94c44573e7c22860e2c3dfe349c45f72ba35ad3 Mon Sep 17 00:00:00 2001
From: Dave Chinner <dchinner@xxxxxxxxxx>
Date: Thu, 21 Nov 2013 15:41:06 +1100
Subject: xfs: growfs overruns AGFL buffer on V4 filesystems
From: Dave Chinner <dchinner@xxxxxxxxxx>
commit f94c44573e7c22860e2c3dfe349c45f72ba35ad3 upstream.
This loop in xfs_growfs_data_private() is incorrect for V4
superblocks filesystems:
for (bucket = 0; bucket < XFS_AGFL_SIZE(mp); bucket++)
agfl->agfl_bno[bucket] = cpu_to_be32(NULLAGBLOCK);
For V4 filesystems, we don't have a agfl header structure, and so
XFS_AGFL_SIZE() returns an entire sector's worth of entries, which
we then index from an offset into the sector. Hence: buffer overrun.
This problem was introduced in 3.10 by commit 77c95bba ("xfs: add
CRC checks to the AGFL") which changed the AGFL structure but failed
to update the growfs code to handle the different structures.
Fix it by using the correct offset into the buffer for both V4 and
V5 filesystems.
Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
Reviewed-by: Jie Liu <jeff.liu@xxxxxxxxxx>
Signed-off-by: Ben Myers <bpm@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/xfs/xfs_fsops.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -217,6 +217,8 @@ xfs_growfs_data_private(
*/
nfree = 0;
for (agno = nagcount - 1; agno >= oagcount; agno--, new -= agsize) {
+ __be32 *agfl_bno;
+
/*
* AG freespace header block
*/
@@ -276,8 +278,10 @@ xfs_growfs_data_private(
agfl->agfl_seqno = cpu_to_be32(agno);
uuid_copy(&agfl->agfl_uuid, &mp->m_sb.sb_uuid);
}
+
+ agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, bp);
for (bucket = 0; bucket < XFS_AGFL_SIZE(mp); bucket++)
- agfl->agfl_bno[bucket] = cpu_to_be32(NULLAGBLOCK);
+ agfl_bno[bucket] = cpu_to_be32(NULLAGBLOCK);
error = xfs_bwrite(bp);
xfs_buf_relse(bp);
Patches currently in stable-queue which might be from dchinner@xxxxxxxxxx are
queue-3.12/xfs-underflow-bug-in-xfs_attrlist_by_handle.patch
queue-3.12/xfs-growfs-overruns-agfl-buffer-on-v4-filesystems.patch
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