On Mon, Oct 23, 2023 at 3:15 PM David Sterba <dsterba@xxxxxxx> wrote: > > On Sat, Oct 21, 2023 at 07:40:53PM -0700, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: 78124b0c1d10 Merge branch 'for-next/core' into for-kernelci > > git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci > > console output: https://syzkaller.appspot.com/x/log.txt?x=1557da89680000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=f27cd6e68911e026 > > dashboard link: https://syzkaller.appspot.com/bug?extid=b2869947e0c9467a41b6 > > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > > userspace arch: arm64 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=137ac45d680000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16e4640b680000 > > > > Downloadable assets: > > disk image: https://storage.googleapis.com/syzbot-assets/bd512de820ae/disk-78124b0c.raw.xz > > vmlinux: https://storage.googleapis.com/syzbot-assets/a47a437b1d4f/vmlinux-78124b0c.xz > > kernel image: https://storage.googleapis.com/syzbot-assets/3ae8b966bcd7/Image-78124b0c.gz.xz > > mounted in repro: https://storage.googleapis.com/syzbot-assets/d5d514495f15/mount_0.gz > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+b2869947e0c9467a41b6@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low! > > #syz invalid > > This is a frequent warning, can be worked around by increasing > CONFIG_LOCKDEP_CHAINS_BITS in config (18 could be a good value but may > still not be enough). By invalidating a frequently occurring issue we only cause syzbot to report it once again, so it's better to keep the report open until the root cause is resolved. There'll likely be a report (5) soon. We keep CONFIG_LOCKDEP_CHAINS_BITS at 16 for arm64 because (at least in 2022) the kernel used not to boot on GCE arm64 VMs with CONFIG_LOCKDEP_CHAINS_BITS=18. Maybe it's time to try it once more. -- Aleksandr
