On Mon, Nov 21, 2022 at 08:14:43PM -0800, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: eb7081409f94 Linux 6.1-rc6 > git tree: upstream > console+strace: https://syzkaller.appspot.com/x/log.txt?x=12e5bb0d880000 > kernel config: https://syzkaller.appspot.com/x/.config?x=8cdf448d3b35234 > dashboard link: https://syzkaller.appspot.com/bug?extid=1d8c82e66f2e76b6b427 > compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=169e86fd880000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1691470d880000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/4a019f55c517/disk-eb708140.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/eb36e890aa8b/vmlinux-eb708140.xz > kernel image: https://storage.googleapis.com/syzbot-assets/feee2c23ec64/bzImage-eb708140.xz > mounted in repro: https://storage.googleapis.com/syzbot-assets/c5c0a12afa51/mount_2.gz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+1d8c82e66f2e76b6b427@xxxxxxxxxxxxxxxxxxxxxxxxx > > loop0: detected capacity change from 0 to 32768 > XFS (loop0): Mounting V5 Filesystem > XFS (loop0): Log inconsistent (didn't find previous header) > XFS: Assertion failed: 0, file: fs/xfs/xfs_log_recover.c, line: 429 Not a bug. Not even close to a bug. The kernel was clearly ompiled with CONFIG_XFS_DEBUG=y, which will trigger debug asserts when things go wrong in ways that should not ever happen in normal circumstances. Turn off CONFIG_XFS_DEBUG, and this failure will return -EFSCORRUPTED as expected because syzbot fed it a corrupt log. THe mount will simply fail as you'd expect given the malicious corruption that syzbot has performed. If syzbot is going to maliciously corrupt XFS filesytsems and then try to abuse them, then syzbot has two choices. Either: 1. do not enable CONFIG_XFS_DEBUG; or 2. do not report the inevitable stream of ASSERT failures that will be encountered to the XFS list. -Dave. -- Dave Chinner david@xxxxxxxxxxxxx
