Hi Dave, [resent due to smtp error] thanks for the help, now using the for-next branch, there is still an Arithmetic exception, however somewhere else: Program received signal SIGFPE, Arithmetic exception. xfs_ialloc_setup_geometry (mp=mp@entry=0x6a5e60 <xmount>) at xfs_ialloc.c:2792 2792 do_div(icount, igeo->ialloc_blks); Thanks Marc Gesendet: Donnerstag, 17. Oktober 2019 um 00:28 Uhr Von: "Dave Chinner" <david@xxxxxxxxxxxxx> An: "Marc Schönefeld" <marc.schoenefeld@xxxxxxx> Cc: linux-xfs@xxxxxxxxxxxxxxx Betreff: Re: Sanity check for m_ialloc_blks in libxfs_mount() On Wed, Oct 16, 2019 at 09:08:51PM +0200, "Marc Schönefeld" wrote: > Hi all, > > it looks like there is a sanity check missing for the divisor > (m_ialloc_blks) in line 664 of xfsprogs-5.2.1/libxfs/init.c: > Program received signal SIGFPE, Arithmetic exception. > > 0x0000000000427ddf in libxfs_mount (mp=mp@entry=0x6a2de0 <xmount>, sb=sb@entry=0x6a2de0 <xmount>, dev=18446744073709551615, > logdev=<optimized out>, rtdev=<optimized out>, flags=flags@entry=1) at init.c:663 > > which is > > 663 mp->m_maxicount = XFS_FSB_TO_INO(mp, > 664 (mp->m_maxicount / mp->m_ialloc_blks) * > 665 mp->m_ialloc_blks); That's code is gone now. The current calculation in the dev tree is quite different thanks to: commit 3a05ab227ebd5982f910f752692c87005c7b3ad3 Author: Darrick J. Wong <darrick.wong@xxxxxxxxxx> Date: Wed Aug 28 12:08:08 2019 -0400 xfs: refactor inode geometry setup routines Source kernel commit: 494dba7b276e12bc3f6ff2b9b584b6e9f693af45 Migrate all of the inode geometry setup code from xfs_mount.c into a single libxfs function that we can share with xfsprogs. Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxxx> And so it doesn't have a divide-by-zero vector in it anymore. So it's probably best that you update your source tree to the latest for-next and retest. It's almost always a good idea to test against the latest dev tree, that way you aren't finding bugs we've already found and fixed... > In case it would be required I have a reproducer file for this, > which I can share via pm. The bug is reachable from user input via > the "xfs_db -c _cmd_ _xfsfile_" command. I'm guessing that you are fuzzing filesystem images and the issue is that the inode geometry values in the superblock have been fuzzed to be incorrect? What fuzzer are you using to generate the image, and what's the mkfs.xfs output that was used to create the base image that was then fuzzed? Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx
