Kumar, check out this ABBA deadlock that your upcoming resilient spin lock should address. There are two hash maps and though we have htab->map_locked recursion protection it doesn't help here. On Fri, Dec 6, 2024 at 5:58 AM syzbot <syzbot+0a26db48dcd6d80be6c0@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: feffde684ac2 Merge tag 'for-6.13-rc1-tag' of git://git.ker.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=1476e0f8580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6851fe4f61792030 > dashboard link: https://syzkaller.appspot.com/bug?extid=0a26db48dcd6d80be6c0 > compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17d9c8df980000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1276e0f8580000 > > Downloadable assets: > disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-feffde68.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/e9751e7030ea/vmlinux-feffde68.xz > kernel image: https://storage.googleapis.com/syzbot-assets/f7bf928b44d6/bzImage-feffde68.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+0a26db48dcd6d80be6c0@xxxxxxxxxxxxxxxxxxxxxxxxx > > ====================================================== > WARNING: possible circular locking dependency detected > 6.13.0-rc1-syzkaller-00025-gfeffde684ac2 #0 Not tainted > ------------------------------------------------------ > syz-executor207/6807 is trying to acquire lock: > ffff88802632eca0 (&htab->lockdep_key#434){....}-{2:2}, at: htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] > ffff88802632eca0 (&htab->lockdep_key#434){....}-{2:2}, at: htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1484 > > but task is already holding lock: > ffff888031440e20 (&htab->lockdep_key#435){....}-{2:2}, at: htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] > ffff888031440e20 (&htab->lockdep_key#435){....}-{2:2}, at: htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1484 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #1 (&htab->lockdep_key#435){....}-{2:2}: > __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] > _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 > htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] > htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1484 > bpf_prog_2c29ac5cdc6b1842+0x43/0x47 > bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] > __bpf_prog_run include/linux/filter.h:701 [inline] > bpf_prog_run include/linux/filter.h:708 [inline] > __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline] > bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2392 > __bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95 > __traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95 > __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:94 [inline] > class_preempt_notrace_destructor include/linux/preempt.h:481 [inline] > trace_contention_begin.constprop.0+0xf3/0x170 include/trace/events/lock.h:95 > __pv_queued_spin_lock_slowpath+0x10b/0xc90 kernel/locking/qspinlock.c:402 > pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline] > queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] > queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] > do_raw_spin_lock+0x210/0x2c0 kernel/locking/spinlock_debug.c:116 > htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] > htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1484 > bpf_prog_2c29ac5cdc6b1842+0x43/0x47 > bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] > __bpf_prog_run include/linux/filter.h:701 [inline] > bpf_prog_run include/linux/filter.h:708 [inline] > __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline] > bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2392 > __bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95 > __traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95 > trace_contention_begin+0xd2/0x140 include/trace/events/lock.h:95 > __mutex_lock_common kernel/locking/mutex.c:587 [inline] > __mutex_lock+0x1a8/0xa60 kernel/locking/mutex.c:735 > futex_cleanup_begin kernel/futex/core.c:1070 [inline] > futex_exit_release+0x2a/0x220 kernel/futex/core.c:1122 > exit_mm_release+0x19/0x30 kernel/fork.c:1660 > exit_mm kernel/exit.c:543 [inline] > do_exit+0x88b/0x2d70 kernel/exit.c:925 > do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 > __do_sys_exit_group kernel/exit.c:1098 [inline] > __se_sys_exit_group kernel/exit.c:1096 [inline] > __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096 > x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > -> #0 (&htab->lockdep_key#434){....}-{2:2}: > 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+0x249e/0x3c40 kernel/locking/lockdep.c:5226 > lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 > __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] > _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 > htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] > htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1484 > bpf_prog_2c29ac5cdc6b1842+0x43/0x47 > bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] > __bpf_prog_run include/linux/filter.h:701 [inline] > bpf_prog_run include/linux/filter.h:708 [inline] > __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline] > bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2392 > __bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95 > __traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95 > __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:94 [inline] > class_preempt_notrace_destructor include/linux/preempt.h:481 [inline] > trace_contention_begin.constprop.0+0xf3/0x170 include/trace/events/lock.h:95 > __pv_queued_spin_lock_slowpath+0x10b/0xc90 kernel/locking/qspinlock.c:402 > pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline] > queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] > queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] > do_raw_spin_lock+0x210/0x2c0 kernel/locking/spinlock_debug.c:116 > htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] > htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1484 > bpf_prog_2c29ac5cdc6b1842+0x43/0x47 > bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] > __bpf_prog_run include/linux/filter.h:701 [inline] > bpf_prog_run include/linux/filter.h:708 [inline] > __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline] > bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2392 > __bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95 > __traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95 > trace_contention_begin+0xd2/0x140 include/trace/events/lock.h:95 > __mutex_lock_common kernel/locking/mutex.c:587 [inline] > __mutex_lock+0x1a8/0xa60 kernel/locking/mutex.c:735 > uprobe_clear_state+0x4b/0x1a0 kernel/events/uprobes.c:1771 > __mmput+0x79/0x4c0 kernel/fork.c:1349 > mmput+0x62/0x70 kernel/fork.c:1375 > exit_mm kernel/exit.c:570 [inline] > do_exit+0x9bf/0x2d70 kernel/exit.c:925 > do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 > __do_sys_exit_group kernel/exit.c:1098 [inline] > __se_sys_exit_group kernel/exit.c:1096 [inline] > __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096 > x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > other info that might help us debug this: > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(&htab->lockdep_key#435); > lock(&htab->lockdep_key#434); > lock(&htab->lockdep_key#435); > lock(&htab->lockdep_key#434); > > *** DEADLOCK *** > > 4 locks held by syz-executor207/6807: > #0: ffffffff8e2d69e8 (delayed_uprobe_lock){+.+.}-{4:4}, at: uprobe_clear_state+0x4b/0x1a0 kernel/events/uprobes.c:1771 > #1: ffffffff8e1bb500 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] > #1: ffffffff8e1bb500 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] > #1: ffffffff8e1bb500 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2350 [inline] > #1: ffffffff8e1bb500 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2392 > #2: ffff888031440e20 (&htab->lockdep_key#435){....}-{2:2}, at: htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] > #2: ffff888031440e20 (&htab->lockdep_key#435){....}-{2:2}, at: htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1484 > #3: ffffffff8e1bb500 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] > #3: ffffffff8e1bb500 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] > #3: ffffffff8e1bb500 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2350 [inline] > #3: ffffffff8e1bb500 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2392 > > stack backtrace: > CPU: 3 UID: 0 PID: 6807 Comm: syz-executor207 Not tainted 6.13.0-rc1-syzkaller-00025-gfeffde684ac2 #0 > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 > print_circular_bug+0x419/0x5d0 kernel/locking/lockdep.c:2074 > check_noncircular+0x31a/0x400 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+0x249e/0x3c40 kernel/locking/lockdep.c:5226 > lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 > __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] > _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 > htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] > htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1484 > bpf_prog_2c29ac5cdc6b1842+0x43/0x47 > bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] > __bpf_prog_run include/linux/filter.h:701 [inline] > bpf_prog_run include/linux/filter.h:708 [inline] > __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline] > bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2392 > __bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95 > __traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95 > __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:94 [inline] > class_preempt_notrace_destructor include/linux/preempt.h:481 [inline] > trace_contention_begin.constprop.0+0xf3/0x170 include/trace/events/lock.h:95 > __pv_queued_spin_lock_slowpath+0x10b/0xc90 kernel/locking/qspinlock.c:402 > pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline] > queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] > queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] > do_raw_spin_lock+0x210/0x2c0 kernel/locking/spinlock_debug.c:116 > htab_lock_bucket kernel/bpf/hashtab.c:167 [inline] > htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1484 > bpf_prog_2c29ac5cdc6b1842+0x43/0x47 > bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] > __bpf_prog_run include/linux/filter.h:701 [inline] > bpf_prog_run include/linux/filter.h:708 [inline] > __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline] > bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2392 > __bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95 > __traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95 > trace_contention_begin+0xd2/0x140 include/trace/events/lock.h:95 > __mutex_lock_common kernel/locking/mutex.c:587 [inline] > __mutex_lock+0x1a8/0xa60 kernel/locking/mutex.c:735 > uprobe_clear_state+0x4b/0x1a0 kernel/events/uprobes.c:1771 > __mmput+0x79/0x4c0 kernel/fork.c:1349 > mmput+0x62/0x70 kernel/fork.c:1375 > exit_mm kernel/exit.c:570 [inline] > do_exit+0x9bf/0x2d70 kernel/exit.c:925 > do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 > __do_sys_exit_group kernel/exit.c:1098 [inline] > __se_sys_exit_group kernel/exit.c:1096 [inline] > __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096 > x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7fe3838cedf9 > Code: Unable to access opcode bytes at 0x7fe3838cedcf. > RSP: 002b:00007ffd9c887888 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe3838cedf9 > RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 > RBP: 00007fe38395b390 R08: ffffffffffffffb0 R09: 00007ffd9c887910 > R10: 00007ffd9c887910 R11: 0000000000000246 R12: 00007fe38395b390 > R13: 0000000000000000 R14: 00007fe38395bf20 R15: 00007fe38389c900 > </TASK> > > > --- > 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 syzkaller@xxxxxxxxxxxxxxxx. > > 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
