====================================================== WARNING: possible circular locking dependency detected 5.15.161-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/5057 is trying to acquire lock: ffff88807a1840d8 (&sighand->siglock){-...}-{2:2}, at: __lock_task_sighand+0x11a/0x290 kernel/signal.c:1404 but task is already holding lock: ffff8880b9b35bb8 (lock#11){+.+.}-{2:2}, at: local_lock_acquire+0xd/0x170 include/linux/local_lock_internal.h:28 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (lock#11){+.+.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 local_lock_acquire+0x29/0x170 include/linux/local_lock_internal.h:29 __mmap_lock_do_trace_acquire_returned+0x7c/0x340 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+0x612/0x930 kernel/bpf/stackmap.c:185 __bpf_get_stack+0x495/0x570 kernel/bpf/stackmap.c:496 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1490 [inline] bpf_get_stack_raw_tp+0x1b2/0x220 kernel/trace/bpf_trace.c:1480 0xffffffffa002cd2e bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917 trace_tlb_flush+0xed/0x110 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x748/0xa30 context_switch kernel/sched/core.c:5016 [inline] __schedule+0x1167/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 kobject_uevent_env+0x506/0x8d0 lib/kobject_uevent.c:586 kobject_synth_uevent+0x4eb/0xae0 lib/kobject_uevent.c:208 uevent_store+0x20/0x60 drivers/base/core.c:2425 kernfs_fop_write_iter+0x3a2/0x4f0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0xacf/0xe50 fs/read_write.c:594 ksys_write+0x1a2/0x2c0 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:368 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 raw_spin_rq_lock kernel/sched/sched.h:1326 [inline] rq_lock kernel/sched/sched.h:1621 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11495 sched_cgroup_fork+0x2d3/0x330 kernel/sched/core.c:4466 copy_process+0x224a/0x3ef0 kernel/fork.c:2320 kernel_clone+0x210/0x960 kernel/fork.c:2604 kernel_thread+0x168/0x1e0 kernel/fork.c:2656 rest_init+0x21/0x330 init/main.c:706 start_kernel+0x48c/0x540 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb -> #1 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __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+0xae/0x1300 kernel/sched/core.c:4030 signal_wake_up_state kernel/signal.c:770 [inline] signal_wake_up include/linux/sched/signal.h:421 [inline] complete_signal+0x5a0/0x9a0 kernel/signal.c:1062 __send_signal+0xaaf/0xd40 kernel/signal.c:1182 do_notify_parent+0xc1e/0xf00 kernel/signal.c:2113 exit_notify kernel/exit.c:729 [inline] do_exit+0x1464/0x2480 kernel/exit.c:892 do_group_exit+0x144/0x310 kernel/exit.c:994 __do_sys_exit_group kernel/exit.c:1005 [inline] __se_sys_exit_group kernel/exit.c:1003 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1003 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&sighand->siglock){-...}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x11a/0x290 kernel/signal.c:1404 lock_task_sighand include/linux/sched/signal.h:704 [inline] do_send_sig_info kernel/signal.c:1293 [inline] group_send_sig_info+0x23f/0x2d0 kernel/signal.c:1442 bpf_send_signal_common+0x2d8/0x420 kernel/trace/bpf_trace.c:824 ____bpf_send_signal kernel/trace/bpf_trace.c:829 [inline] bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:827 bpf_prog_9fbc3d1d47c9b36c+0x1a/0x124 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run4+0x1ea/0x390 kernel/trace/bpf_trace.c:1919 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:44 [inline] __mmap_lock_do_trace_acquire_returned+0x2d6/0x340 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] do_user_addr_fault arch/x86/mm/fault.c:1298 [inline] handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x564/0x700 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568 other info that might help us debug this: Chain exists of: &sighand->siglock --> &rq->__lock --> lock#11 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#11); lock(&rq->__lock); lock(lock#11); lock(&sighand->siglock); *** DEADLOCK *** 5 locks held by syz-executor.1/5057: #0: ffff88807c6c4028 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807c6c4028 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1298 [inline] #0: ffff88807c6c4028 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1445 [inline] #0: ffff88807c6c4028 (&mm->mmap_lock){++++}-{3:3}, at: exc_page_fault+0x181/0x700 arch/x86/mm/fault.c:1501 #1: ffff8880b9b35bb8 (lock#11){+.+.}-{2:2}, at: local_lock_acquire+0xd/0x170 include/linux/local_lock_internal.h:28 #2: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #3: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #4: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 stack backtrace: CPU: 1 PID: 5057 Comm: syz-executor.1 Not tainted 5.15.161-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x11a/0x290 kernel/signal.c:1404 lock_task_sighand include/linux/sched/signal.h:704 [inline] do_send_sig_info kernel/signal.c:1293 [inline] group_send_sig_info+0x23f/0x2d0 kernel/signal.c:1442 bpf_send_signal_common+0x2d8/0x420 kernel/trace/bpf_trace.c:824 ____bpf_send_signal kernel/trace/bpf_trace.c:829 [inline] bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:827 bpf_prog_9fbc3d1d47c9b36c+0x1a/0x124 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run4+0x1ea/0x390 kernel/trace/bpf_trace.c:1919 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:44 [inline] __mmap_lock_do_trace_acquire_returned+0x2d6/0x340 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] do_user_addr_fault arch/x86/mm/fault.c:1298 [inline] handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x564/0x700 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568 RIP: 0033:0x7f4261682fe6 Code: 00 00 00 90 48 8b 0d 11 a7 cb 00 4c 63 05 fa a6 cb 00 48 8b 15 fb a6 cb 00 49 01 c8 48 39 ca 72 18 48 8d 42 04 4c 39 c0 73 0f <48> 89 3a 48 83 c2 08 48 89 15 dc a6 cb 00 c3 50 48 8d 35 66 e4 0a RSP: 002b:00007ffe016f3578 EFLAGS: 00010287 RAX: 0000001b2c424000 RBX: 0000000000000001 RCX: 0000001b2c420000 RDX: 0000001b2c423ffc RSI: 0000000000000727 RDI: ffffffff81b22727 RBP: 00007f4261057008 R08: 0000001b2ca20000 R09: 0000000000000000 R10: 0000000081b22727 R11: 0000000081b2272b R12: 000000000000043d R13: ffffffff81b22429 R14: ffffffff81b22727 R15: 00007f426180c018