On Sun, 2017-01-08 at 15:52 +0100, Christoph Hellwig wrote: > On Sun, Jan 08, 2017 at 09:48:44AM -0500, Mimi Zohar wrote: > > IMA takes the i_rwsem (fomerly i_mutex) before reading the file to > > synchronize calculating the file hash and validating the file's > > hash/signature stored as security.ima xattr > > Well, it shouldn't do that. In the I/O path i_rwsem is up to the > fs to use. Various other file systems also take it internally for > reads, although mostly only for direct I/O. But not normally for a normal file read. For direct I/O, IMA fails the file hash/signature verification, measurement, audit unless the IMA "permit_directio" rule is defined. > So the answer here is that ima needs to stop playing with i_rwsem. Unless something has changed recently, to synchronize reading files to calculate the file hash and writing xattrs it has to take the i_rwsem prior to reading the file. Mimi -- 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
