From cb7ccb9924bb3596f211badf0d2becf131a979cd Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Tue, 17 Apr 2018 19:10:15 -0700 Subject: [PATCH] xfs: don't fail when converting shortform attr to long form during ATTR_REPLACE commit 7b38460dc8e4eafba06c78f8e37099d3b34d473c upstream. Kanda Motohiro reported that expanding a tiny xattr into a large xattr fails on XFS because we remove the tiny xattr from a shortform fork and then try to re-add it after converting the fork to extents format having not removed the ATTR_REPLACE flag. This fails because the attr is no longer present, causing a fs shutdown. This is derived from the patch in his bug report, but we really shouldn't ignore a nonzero retval from the remove call. CVE: CVE-2018-18690 Upstream-Status: Backport Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199119 Reported-by: kanda.motohiro@gmail.com Reviewed-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Darrick J. Wong Signed-off-by: Ben Hutchings Signed-off-by: Sasha Levin Signed-off-by: Andreas Wellving --- fs/xfs/libxfs/xfs_attr.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c index 6249c92671de..ea66f04f46f7 100644 --- a/fs/xfs/libxfs/xfs_attr.c +++ b/fs/xfs/libxfs/xfs_attr.c @@ -501,7 +501,14 @@ xfs_attr_shortform_addname(xfs_da_args_t *args) if (args->flags & ATTR_CREATE) return retval; retval = xfs_attr_shortform_remove(args); - ASSERT(retval == 0); + if (retval) + return retval; + /* + * Since we have removed the old attr, clear ATTR_REPLACE so + * that the leaf format add routine won't trip over the attr + * not being around. + */ + args->flags &= ~ATTR_REPLACE; } if (args->namelen >= XFS_ATTR_SF_ENTSIZE_MAX || -- 2.19.2