From: Jan Kara <jack@suse.cz>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org, xfs@oss.sgi.com,
linux-security-module@vger.kernel.org, Jan Kara <jack@suse.cz>
Subject: [PATCH 0/5 v2] fs: Fixes for removing xid bits and security labels
Date: Thu, 18 Dec 2014 13:49:01 +0100 [thread overview]
Message-ID: <1418906946-30695-1-git-send-email-jack@suse.cz> (raw)
Hello,
warning in XFS made me look into detail into how clearing of suid / sgid
bits and security labels is done. And I've spotted a few issues:
1) MS_NOSEC handling is broken - we set it after each file_remove_suid() call.
However we needn't have removed suid bit simply because we have
CAP_SYS_FSID and further writes to the file from processes without this
capability still need to clear the suid bit.
2) file_remove_suid() is a misnomer since it also handles removing of
security labels. It is even more confusing because should_remove_suid()
doesn't return whether file_remove_suid() is needed or not.
3) On truncate we do clear suid bits but not security labels. According to
documentation in include/linux/security.h that's a bug but please correct
me if I'm wrong.
4) ocfs2 doesn't clear security labels - hard to fix, I left it alone for now.
5) XFS didn't provide proper exclusion for clearing mode bits.
This series aims at fixing above issues.
Since v1 I have removed bogus patch changing inode_set_flags(), I have
updated changelog of patch 4/5 to better explain why ->inode_killpriv should
be called and I have included a fix for MS_NOSEC handling in this series.
Al, can you please merge the patches? Thanks!
Honza
next reply other threads:[~2014-12-18 12:49 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-18 12:49 Jan Kara [this message]
2014-12-18 12:49 ` [PATCH 1/5] fs: Fix S_NOSEC handling Jan Kara
2014-12-18 12:49 ` [PATCH 2/5] fs: Rename file_remove_suid() to file_remove_privs() Jan Kara
2014-12-18 12:49 ` [PATCH 3/5] fs: Provide function telling whether file_remove_privs() will do anything Jan Kara
2014-12-18 12:49 ` [PATCH 4/5] fs: Call security_ops->inode_killpriv on truncate Jan Kara
2014-12-18 12:49 ` [PATCH 5/5] xfs: Correctly lock inode when removing suid and security marks Jan Kara
2015-01-08 9:18 ` [PATCH 0/5 v2] fs: Fixes for removing xid bits and security labels Jan Kara
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