blob: 43920593849a95f49e4dc0a47f7a9f3f2c6af05b [file] [log] [blame]
From f4020438fab05364018c91f7e02ebdd192085933 Mon Sep 17 00:00:00 2001
From: Eric Sandeen <>
Date: Wed, 26 Aug 2020 14:11:58 -0700
Subject: [PATCH] xfs: fix boundary test in xfs_attr_shortform_verify
commit f4020438fab05364018c91f7e02ebdd192085933 upstream.
The boundary test for the fixed-offset parts of xfs_attr_sf_entry in
xfs_attr_shortform_verify is off by one, because the variable array
at the end is defined as nameval[1] not nameval[].
Hence we need to subtract 1 from the calculation.
This can be shown by:
# touch file
# setfattr -n root.a file
and verifications will fail when it's written to disk.
This only matters for a last attribute which has a single-byte name
and no value, otherwise the combination of namelen & valuelen will
push endp further out and this test won't fail.
Fixes: 1e1bbd8e7ee06 ("xfs: create structure verifier function for shortform xattrs")
Signed-off-by: Eric Sandeen <>
Reviewed-by: Darrick J. Wong <>
Signed-off-by: Darrick J. Wong <>
Reviewed-by: Christoph Hellwig <>
Signed-off-by: Paul Gortmaker <>
diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
index 8623c815164a..383b08f2ac61 100644
--- a/fs/xfs/libxfs/xfs_attr_leaf.c
+++ b/fs/xfs/libxfs/xfs_attr_leaf.c
@@ -1036,8 +1036,10 @@ xfs_attr_shortform_verify(
* struct xfs_attr_sf_entry has a variable length.
* Check the fixed-offset parts of the structure are
* within the data buffer.
+ * xfs_attr_sf_entry is defined with a 1-byte variable
+ * array at the end, so we must subtract that off.
- if (((char *)sfep + sizeof(*sfep)) >= endp)
+ if (((char *)sfep + sizeof(*sfep) - 1) >= endp)
return __this_address;
/* Don't allow names with known bad length. */