On Fri, Nov 29, 2024 at 11:57 PM Kent Overstreet <[email protected]> wrote: > > On Fri, Nov 29, 2024 at 11:02:16PM +0100, Aleksandr Nogikh wrote: > > Hi Kent, > > > > For reopened bugs, syzbot appends (2), (3), etc. at the end of the > > title. In this case, there are no numbers, so it has never reported > > anything with such a title before. > > > > But it can well be the case that the underlying problem here is the > > same as in some other syzbot report (you could then "#syz dup" the new > > to the older one). If you happen to see patterns in such duplicate > > reports, please let us know and we'll try to improve the crash report > > parsing logic. > > It looks identical to this one which I closed last night > > https://syzkaller.appspot.com/bug?extid=e088be3c2d5c05aaac35 > > Is that a parsing issue? The lockdep splats don't just look similar to > me, they look identical.
Yes, that's exactly a report parsing issue. In this case it's even one that's a bit more involved than usually, so I've filed an issue to discuss it in more detail: https://github.com/google/syzkaller/issues/5558 > > I've got another one that I closed last night that it seems might be > confusing for syzbot: > https://syzkaller.appspot.com/bug?extid=64e6509c7f777aec3a24 > > I fixed the patch that introduced the bug (it was only in -next), but I > don't seem to have a way to tell syzbot not to reopen it unless it sees > the updated patch. That's actually the default behavior of syzbot: if you set the fix commit title via `#syz fix` or via a `Reported-by` tag, syzbot will first wait until the fix commit has reached all the trees that are fuzzed and will reopen the issue with a " (2)" suffix only if the failure occurred on some patched tree. However, syzbot parsed these two bug reports differently. It identified them as: * possible deadlock in __bch2_trans_relock * possible deadlock in trans_set_locked So, from its viewpoint, these are totally "different". If you know the exact duplicate issue, please send a #syz dup command(s) to remove them from the web dashboard (and Cc [email protected] so that we know that there was a parsing problem). -- Aleksandr > > Probably not a real issue with this particular bug - this exact situation > is pretty rare, but I do have bugs accumulating in my dashboard that > seem to have been fixed but I don't have a good way to close since I > don't know the patch that fixed them (not going to bisect 20+ fixes...) > > > > > -- > > Aleksandr > > > > On Fri, Nov 29, 2024 at 9:25 PM Kent Overstreet > > <[email protected]> wrote: > > > > > > On Fri, Nov 29, 2024 at 09:09:32AM -0800, syzbot wrote: > > > > Hello, > > > > > > > > syzbot found the following issue on: > > > > > > > > HEAD commit: 7b1d1d4cfac0 Merge remote-tracking branch > > > > 'iommu/arm/smmu'.. > > > > 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=17d6af78580000 > > > > kernel config: > > > > https://syzkaller.appspot.com/x/.config?x=9bc44a6de1ceb5d6 > > > > dashboard link: > > > > https://syzkaller.appspot.com/bug?extid=78f4eb354f5ca6c1e6eb > > > > 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=107bdf5f980000 > > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13ae49e8580000 > > > > > > > > Downloadable assets: > > > > disk image: > > > > https://storage.googleapis.com/syzbot-assets/4d4a0162c7c3/disk-7b1d1d4c.raw.xz > > > > vmlinux: > > > > https://storage.googleapis.com/syzbot-assets/a8c47a4be472/vmlinux-7b1d1d4c.xz > > > > kernel image: > > > > https://storage.googleapis.com/syzbot-assets/0e173b91f83e/Image-7b1d1d4c.gz.xz > > > > mounted in repro #1: > > > > https://storage.googleapis.com/syzbot-assets/5ab7b24d2900/mount_0.gz > > > > mounted in repro #2: > > > > https://storage.googleapis.com/syzbot-assets/fbfbb60588c1/mount_2.gz > > > > > > > > IMPORTANT: if you fix the issue, please add the following tag to the > > > > commit: > > > > Reported-by: [email protected] > > > > > > > > ====================================================== > > > > WARNING: possible circular locking dependency detected > > > > 6.12.0-syzkaller-g7b1d1d4cfac0 #0 Not tainted > > > > ------------------------------------------------------ > > > > syz-executor203/6432 is trying to acquire lock: > > > > ffff0000da100128 (bcachefs_btree){+.+.}-{0:0}, at: > > > > trans_set_locked+0x5c/0x21c fs/bcachefs/btree_locking.h:193 > > > > > > > > but task is already holding lock: > > > > ffff0000dc661548 (&c->fsck_error_msgs_lock){+.+.}-{3:3}, at: > > > > __bch2_fsck_err+0x344/0x2544 fs/bcachefs/error.c:282 > > > > > > > > which lock already depends on the new lock. > > > > > > > > > > > > the existing dependency chain (in reverse order) is: > > > > > > > > -> #1 (&c->fsck_error_msgs_lock){+.+.}-{3:3}: > > > > __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608 > > > > __mutex_lock kernel/locking/mutex.c:752 [inline] > > > > mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804 > > > > __bch2_fsck_err+0x344/0x2544 fs/bcachefs/error.c:282 > > > > bch2_check_alloc_hole_freespace+0x5fc/0xd74 > > > > fs/bcachefs/alloc_background.c:1278 > > > > bch2_check_alloc_info+0x1174/0x26f8 > > > > fs/bcachefs/alloc_background.c:1547 > > > > bch2_run_recovery_pass+0xe4/0x1d4 > > > > fs/bcachefs/recovery_passes.c:191 > > > > bch2_run_online_recovery_passes+0xa4/0x174 > > > > fs/bcachefs/recovery_passes.c:212 > > > > bch2_fsck_online_thread_fn+0x150/0x3e8 fs/bcachefs/chardev.c:799 > > > > thread_with_stdio_fn+0x64/0x134 > > > > fs/bcachefs/thread_with_file.c:298 > > > > kthread+0x288/0x310 kernel/kthread.c:389 > > > > ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862 > > > > > > > > -> #0 (bcachefs_btree){+.+.}-{0:0}: > > > > check_prev_add kernel/locking/lockdep.c:3161 [inline] > > > > check_prevs_add kernel/locking/lockdep.c:3280 [inline] > > > > validate_chain kernel/locking/lockdep.c:3904 [inline] > > > > __lock_acquire+0x33f8/0x77c8 kernel/locking/lockdep.c:5202 > > > > lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5825 > > > > trans_set_locked+0x88/0x21c fs/bcachefs/btree_locking.h:194 > > > > __bch2_trans_relock+0x2a0/0x394 fs/bcachefs/btree_locking.c:785 > > > > bch2_trans_relock+0x24/0x34 fs/bcachefs/btree_locking.c:793 > > > > __bch2_fsck_err+0x1664/0x2544 fs/bcachefs/error.c:363 > > > > bch2_check_alloc_hole_freespace+0x5fc/0xd74 > > > > fs/bcachefs/alloc_background.c:1278 > > > > bch2_check_alloc_info+0x1174/0x26f8 > > > > fs/bcachefs/alloc_background.c:1547 > > > > bch2_run_recovery_pass+0xe4/0x1d4 > > > > fs/bcachefs/recovery_passes.c:191 > > > > bch2_run_online_recovery_passes+0xa4/0x174 > > > > fs/bcachefs/recovery_passes.c:212 > > > > bch2_fsck_online_thread_fn+0x150/0x3e8 fs/bcachefs/chardev.c:799 > > > > thread_with_stdio_fn+0x64/0x134 > > > > fs/bcachefs/thread_with_file.c:298 > > > > kthread+0x288/0x310 kernel/kthread.c:389 > > > > ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862 > > > > > > > > other info that might help us debug this: > > > > > > > > Possible unsafe locking scenario: > > > > > > > > CPU0 CPU1 > > > > ---- ---- > > > > lock(&c->fsck_error_msgs_lock); > > > > lock(bcachefs_btree); > > > > lock(&c->fsck_error_msgs_lock); > > > > lock(bcachefs_btree); > > > > > > > > *** DEADLOCK *** > > > > > > > > 3 locks held by syz-executor203/6432: > > > > #0: ffff0000dc600278 (&c->state_lock){++++}-{3:3}, at: > > > > bch2_run_online_recovery_passes+0x3c/0x174 > > > > fs/bcachefs/recovery_passes.c:204 > > > > #1: ffff0000dc604398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: > > > > srcu_lock_acquire+0x18/0x54 include/linux/srcu.h:150 > > > > #2: ffff0000dc661548 (&c->fsck_error_msgs_lock){+.+.}-{3:3}, at: > > > > __bch2_fsck_err+0x344/0x2544 fs/bcachefs/error.c:282 > > > > > > > > stack backtrace: > > > > CPU: 1 UID: 0 PID: 6432 Comm: syz-executor203 Not tainted > > > > 6.12.0-syzkaller-g7b1d1d4cfac0 #0 > > > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > > > Google 09/13/2024 > > > > Call trace: > > > > show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:484 (C) > > > > __dump_stack lib/dump_stack.c:94 [inline] > > > > dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120 > > > > dump_stack+0x1c/0x28 lib/dump_stack.c:129 > > > > print_circular_bug+0x154/0x1c0 kernel/locking/lockdep.c:2074 > > > > check_noncircular+0x310/0x404 kernel/locking/lockdep.c:2206 > > > > check_prev_add kernel/locking/lockdep.c:3161 [inline] > > > > check_prevs_add kernel/locking/lockdep.c:3280 [inline] > > > > validate_chain kernel/locking/lockdep.c:3904 [inline] > > > > __lock_acquire+0x33f8/0x77c8 kernel/locking/lockdep.c:5202 > > > > lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5825 > > > > trans_set_locked+0x88/0x21c fs/bcachefs/btree_locking.h:194 > > > > __bch2_trans_relock+0x2a0/0x394 fs/bcachefs/btree_locking.c:785 > > > > bch2_trans_relock+0x24/0x34 fs/bcachefs/btree_locking.c:793 > > > > __bch2_fsck_err+0x1664/0x2544 fs/bcachefs/error.c:363 > > > > bch2_check_alloc_hole_freespace+0x5fc/0xd74 > > > > fs/bcachefs/alloc_background.c:1278 > > > > bch2_check_alloc_info+0x1174/0x26f8 fs/bcachefs/alloc_background.c:1547 > > > > bch2_run_recovery_pass+0xe4/0x1d4 fs/bcachefs/recovery_passes.c:191 > > > > bch2_run_online_recovery_passes+0xa4/0x174 > > > > fs/bcachefs/recovery_passes.c:212 > > > > bch2_fsck_online_thread_fn+0x150/0x3e8 fs/bcachefs/chardev.c:799 > > > > thread_with_stdio_fn+0x64/0x134 fs/bcachefs/thread_with_file.c:298 > > > > kthread+0x288/0x310 kernel/kthread.c:389 > > > > ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862 > > > > > > > > > > > > --- > > > > This report is generated by a bot. It may contain errors. > > > > See https://goo.gl/tpsmEJ for more information about syzbot. > > > > syzbot engineers can be reached at [email protected]. > > > > > > > > syzbot will keep track of this issue. See: > > > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > > > > > > > If the report is already addressed, let syzbot know by replying with: > > > > #syz fix: exact-commit-title > > > > > > > > If you want syzbot to run the reproducer, reply with: > > > > #syz test: git://repo/address.git branch-or-commit-hash > > > > If you attach or paste a git patch, syzbot will apply it before testing. > > > > > > > > If you want to overwrite report's subsystems, reply with: > > > > #syz set subsystems: new-subsystem > > > > (See the list of subsystem names on the web dashboard) > > > > > > > > If the report is a duplicate of another one, reply with: > > > > #syz dup: exact-subject-of-another-report > > > > > > > > If you want to undo deduplication, reply with: > > > > #syz undup > > > > > > syzbot seems to now be re-opening bugs just because the patch hasn't > > > been merged into the branch it's testing? > > >
