====================================================== WARNING: possible circular locking dependency detected 6.1.92-syzkaller #0 Not tainted ------------------------------------------------------ syz-fuzzer/3544 is trying to acquire lock: ffff8880b9835e90 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b9835e90 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x84/0x670 mm/mmap_lock.c:237 but task is already holding lock: ffff8880b9828358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&base->lock){-.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 lock_timer_base+0x120/0x260 kernel/time/timer.c:999 __mod_timer+0x1cb/0xee0 kernel/time/timer.c:1072 queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1704 psi_task_change+0xf9/0x270 kernel/sched/psi.c:924 psi_enqueue kernel/sched/stats.h:141 [inline] enqueue_task+0x2fd/0x3a0 kernel/sched/core.c:2056 activate_task kernel/sched/core.c:2088 [inline] wake_up_new_task+0x4f5/0xca0 kernel/sched/core.c:4742 kernel_clone+0x4ed/0x920 kernel/fork.c:2713 user_mode_thread+0x12e/0x190 kernel/fork.c:2758 rest_init+0x23/0x300 init/main.c:699 start_kernel+0x0/0x53f init/main.c:894 start_kernel+0x496/0x53f init/main.c:1141 secondary_startup_64_no_verify+0xcf/0xdb -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 raw_spin_rq_lock kernel/sched/sched.h:1354 [inline] rq_lock kernel/sched/sched.h:1644 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11869 sched_cgroup_fork+0x374/0x400 kernel/sched/core.c:4686 copy_process+0x2442/0x4060 kernel/fork.c:2384 kernel_clone+0x222/0x920 kernel/fork.c:2682 user_mode_thread+0x12e/0x190 kernel/fork.c:2758 rest_init+0x23/0x300 init/main.c:699 start_kernel+0x0/0x53f init/main.c:894 start_kernel+0x496/0x53f init/main.c:1141 secondary_startup_64_no_verify+0xcf/0xdb -> #1 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xad/0x12e0 kernel/sched/core.c:4112 rcu_read_unlock_special+0x3d2/0x540 kernel/rcu/tree_plugin.h:655 __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] put_memcg_path_buf+0xde/0x110 mm/mmap_lock.c:153 __mmap_lock_do_trace_acquire_returned+0x1f7/0x670 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:137 [inline] get_mmap_lock_carefully mm/memory.c:5304 [inline] lock_mm_and_find_vma+0x219/0x2e0 mm/memory.c:5366 do_user_addr_fault arch/x86/mm/fault.c:1343 [inline] handle_page_fault arch/x86/mm/fault.c:1462 [inline] exc_page_fault+0x169/0x660 arch/x86/mm/fault.c:1518 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 -> #0 (lock#10){+.+.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0x9d/0x670 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:137 [inline] stack_map_get_build_id_offset+0x99e/0x9c0 kernel/bpf/stackmap.c:144 __bpf_get_stack+0x495/0x570 kernel/bpf/stackmap.c:452 bpf_prog_e6cf5f9c69743609+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] bpf_prog_run_array include/linux/bpf.h:1635 [inline] trace_call_bpf+0x345/0x6a0 kernel/trace/bpf_trace.c:135 perf_trace_run_bpf_submit+0x7b/0x1d0 kernel/events/core.c:9924 perf_trace_timer_class+0x2c8/0x380 include/trace/events/timer.h:12 trace_timer_cancel include/trace/events/timer.h:138 [inline] debug_deactivate kernel/time/timer.c:832 [inline] detach_timer+0x2f4/0x380 kernel/time/timer.c:878 detach_if_pending kernel/time/timer.c:899 [inline] __mod_timer+0x407/0xee0 kernel/time/timer.c:1076 sk_reset_timer+0x1f/0xb0 net/core/sock.c:3371 inet_csk_reset_xmit_timer include/net/inet_connection_sock.h:234 [inline] tcp_reset_xmit_timer include/net/tcp.h:1347 [inline] tcp_schedule_loss_probe+0x410/0x550 net/ipv4/tcp_output.c:2791 tcp_write_xmit+0x3d7e/0x64c0 net/ipv4/tcp_output.c:2740 __tcp_push_pending_frames+0x97/0x350 net/ipv4/tcp_output.c:2894 tcp_sendmsg_locked+0x37b2/0x4100 net/ipv4/tcp.c:1461 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1489 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] sock_write_iter+0x394/0x4e0 net/socket.c:1143 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7ae/0xba0 fs/read_write.c:584 ksys_write+0x19c/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: lock#10 --> &rq->__lock --> &base->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&base->lock); lock(&rq->__lock); lock(&base->lock); lock(lock#10); *** DEADLOCK *** 4 locks held by syz-fuzzer/3544: #0: ffff888022150130 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1748 [inline] #0: ffff888022150130 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1e/0x40 net/ipv4/tcp.c:1488 #1: ffff8880b9828358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999 #2: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #2: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #2: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: trace_call_bpf+0xbe/0x6a0 kernel/trace/bpf_trace.c:134 #3: ffff88807d2a1058 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #3: ffff88807d2a1058 (&mm->mmap_lock){++++}-{3:3}, at: stack_map_get_build_id_offset+0x232/0x9c0 kernel/bpf/stackmap.c:144 stack backtrace: CPU: 0 PID: 3544 Comm: syz-fuzzer Not tainted 6.1.92-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0x9d/0x670 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:137 [inline] stack_map_get_build_id_offset+0x99e/0x9c0 kernel/bpf/stackmap.c:144 __bpf_get_stack+0x495/0x570 kernel/bpf/stackmap.c:452 bpf_prog_e6cf5f9c69743609+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] bpf_prog_run_array include/linux/bpf.h:1635 [inline] trace_call_bpf+0x345/0x6a0 kernel/trace/bpf_trace.c:135 perf_trace_run_bpf_submit+0x7b/0x1d0 kernel/events/core.c:9924 perf_trace_timer_class+0x2c8/0x380 include/trace/events/timer.h:12 trace_timer_cancel include/trace/events/timer.h:138 [inline] debug_deactivate kernel/time/timer.c:832 [inline] detach_timer+0x2f4/0x380 kernel/time/timer.c:878 detach_if_pending kernel/time/timer.c:899 [inline] __mod_timer+0x407/0xee0 kernel/time/timer.c:1076 sk_reset_timer+0x1f/0xb0 net/core/sock.c:3371 inet_csk_reset_xmit_timer include/net/inet_connection_sock.h:234 [inline] tcp_reset_xmit_timer include/net/tcp.h:1347 [inline] tcp_schedule_loss_probe+0x410/0x550 net/ipv4/tcp_output.c:2791 tcp_write_xmit+0x3d7e/0x64c0 net/ipv4/tcp_output.c:2740 __tcp_push_pending_frames+0x97/0x350 net/ipv4/tcp_output.c:2894 tcp_sendmsg_locked+0x37b2/0x4100 net/ipv4/tcp.c:1461 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1489 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] sock_write_iter+0x394/0x4e0 net/socket.c:1143 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7ae/0xba0 fs/read_write.c:584 ksys_write+0x19c/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x40720e Code: 48 83 ec 38 e8 13 00 00 00 48 83 c4 38 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 f2 48 89 fa 48 89 ce 48 89 df 0f 05 <48> 3d 01 f0 ff ff 76 15 48 f7 d8 48 89 c1 48 c7 c0 ff ff ff ff 48 RSP: 002b:000000c00070f8c0 EFLAGS: 00000212 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000040720e RDX: 0000000000000038 RSI: 000000c000b95fc8 RDI: 0000000000000003 RBP: 000000c00070f900 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 000000c00070fa40 R13: 000000000001dfe8 R14: 000000c0011b1860 R15: 000000c000b78000