[PATCH] reiserfs: Fix corruption during shrinking of xattrs

From: Jeff Mahoney
Date: Tue Apr 13 2010 - 15:39:56 EST


Commit 48b32a3553a54740d236b79a90f20147a25875e3 introduced a problem
that causes corruption when extended attributes are replaced with a
smaller value.

The issue is that the reiserfs_setattr to shrink the xattr file was
moved from before the write to after the write.

The root issue has always been in the reiserfs xattr code, but was
papered over by the fact that in the shrink case, the file would just
be expanded again while the xattr was written.

The end result is that the last 8 bytes of xattr data are lost.

This patch fixes it to use new_size.

This issue was reported at: https://bugzilla.kernel.org/show_bug.cgi?id=14826

Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx>
Cc: stable@xxxxxxxxxx
---

fs/reiserfs/xattr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -553,7 +560,7 @@ reiserfs_xattr_set_handle(struct reiserf
if (!err && new_size < i_size_read(dentry->d_inode)) {
struct iattr newattrs = {
.ia_ctime = current_fs_time(inode->i_sb),
- .ia_size = buffer_size,
+ .ia_size = new_size,
.ia_valid = ATTR_SIZE | ATTR_CTIME,
};

--
Jeff Mahoney
SUSE Labs
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