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 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
