On Wed, Jun 13, 2018 at 10:48:50PM -0300, Rafael Tinoco wrote: > On 13 June 2018 at 18:08, Rafael David Tinoco > <rafaeldtinoco@xxxxxxxxxxxxxx> wrote: > > On Wed, Jun 13, 2018 at 6:00 PM, Greg Kroah-Hartman > > <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > >> On Wed, Jun 13, 2018 at 05:47:49PM -0300, Rafael Tinoco wrote: > >>> Results from Linaro’s test farm. > >>> Regressions detected. > >>> > >>> NOTE: > >>> > >>> 1) LTP vma03 test (cve-2011-2496) broken on v4.4-137-rc1 because of: > >>> > >>> 6ea1dc96a03a mmap: relax file size limit for regular files > >>> bd2f9ce5bacb mmap: introduce sane default mmap limits > >>> > >>> discussion: > >>> > >>> https://github.com/linux-test-project/ltp/issues/341 > >>> > >>> mainline commit (v4.13-rc7): > >>> > >>> 0cc3b0ec23ce Clarify (and fix) MAX_LFS_FILESIZE macros > >>> > >>> should be backported to 4.4.138-rc2 and fixes the issue. > >> > >> Really? That commit says it fixes c2a9737f45e2 ("vfs,mm: fix a dead > >> loop in truncate_inode_pages_range()") which is not in 4.4.y at all. > >> > >> Did you test this out? > > > > Yes, the LTP contains the tests (last comment is the final test for > > arm32, right before Jan tests i686). > > > > Fixing MAX_LFS_FILESIZE fixes the new limit for mmap() brought by > > those 2 commits (file_mmap_size_max()). > > offset tested by the LTP test is 0xfffffffe000. > > file_mmap_size_max gives: 0xFFFFFFFF000 as max value, but only after > > the mentioned patch. > > > > Original intent for this fix was other though. > > To clarify this a bit further. > > The LTP CVE test is breaking in the first call to mmap(), even before > trying to remap and test the security issue. That start happening in > this round because of those mmap() changes and the offset used in the > LTP test. Linus changed limit checks and made them to be related to > MAX_LFS_FILESIZE. Unfortunately, in 4.4 stable, we were missing the > fix for MAX_LFS_FILESIZE (which before commit 0cc3b0ec23ce was less > than the REAL 32 bit limit). > > Commit 0cc3b0ec23ce was made because an user noticed the FS limit not > being what it should be. In our case, the 4.4 stable kernel, we are > facing this 32 bit lower limit (than the real 32 bit real limit), > because of the LTP CVE test, so we need this fix to have the real 32 > bit limit set for that macro (mmap limits did not use that macro > before). > > I have tested in arm32 and Jan Stancek, who first responded to LTP > issue, has tested this in i686 and both worked after that patch was > included to v4.4-137-rc1 (my last test was even with 4.4.138-rc1). > > Hope that helps a bit. Ok, thanks, it didn't apply cleanly but I've fixed it up now. greg k-h
