====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc6-syzkaller-00113-g49a73b1652c5 #0 Not tainted ------------------------------------------------------ syz-executor.1/8723 is trying to acquire lock: ffff888022a28958 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x7a/0x660 kernel/signal.c:1334 but task is already holding lock: ffff8880b953ea58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559 raw_spin_rq_lock kernel/sched/sched.h:1387 [inline] _raw_spin_rq_lock_irqsave kernel/sched/sched.h:1406 [inline] rq_lock_irqsave kernel/sched/sched.h:1685 [inline] class_rq_lock_irqsave_constructor kernel/sched/sched.h:1739 [inline] sched_mm_cid_before_execve+0x114/0x5e0 kernel/sched/core.c:12027 exit_signals+0x34d/0x960 kernel/signal.c:3016 do_exit+0x530/0x2c10 kernel/exit.c:837 __do_sys_exit kernel/exit.c:994 [inline] __se_sys_exit kernel/exit.c:992 [inline] __x64_sys_exit+0x42/0x50 kernel/exit.c:992 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&sighand->siglock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 force_sig_info_to_task+0x7a/0x660 kernel/signal.c:1334 force_sig_fault_to_task kernel/signal.c:1733 [inline] force_sig_fault+0xc5/0x110 kernel/signal.c:1738 kernelmode_fixup_or_oops+0x209/0x2b0 arch/x86/mm/fault.c:750 __bad_area_nosemaphore+0x39f/0x6b0 arch/x86/mm/fault.c:814 do_user_addr_fault+0x557/0x1080 arch/x86/mm/fault.c:1298 handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1563 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 rep_movs_alternative+0x13/0x70 arch/x86/lib/copy_user_64.S:40 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:125 [inline] __copy_from_user_inatomic include/linux/uaccess.h:87 [inline] copy_from_user_nofault+0xe1/0x170 mm/maccess.c:125 bpf_probe_read_user_common kernel/trace/bpf_trace.c:179 [inline] ____bpf_probe_read_user kernel/trace/bpf_trace.c:188 [inline] bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:185 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:1997 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2236 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run4+0x176/0x460 kernel/trace/bpf_trace.c:2422 __bpf_trace_sched_switch+0x13e/0x190 include/trace/events/sched.h:222 __traceiter_sched_switch+0x6c/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x252c/0x5d00 kernel/sched/core.c:6743 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7068 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 seqcount_lockdep_reader_access include/linux/seqlock.h:74 [inline] ktime_get_real_ts64+0xbf/0x570 kernel/time/timekeeping.c:824 __do_sys_gettimeofday kernel/time/time.c:146 [inline] __se_sys_gettimeofday kernel/time/time.c:140 [inline] __x64_sys_gettimeofday+0xd4/0x210 kernel/time/time.c:140 emulate_vsyscall+0x4ea/0xe50 arch/x86/entry/vsyscall/vsyscall_64.c:247 do_user_addr_fault+0x61a/0x1080 arch/x86/mm/fault.c:1346 handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1563 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 _end+0x6a9da000/0x0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&sighand->siglock); lock(&rq->__lock); lock(&sighand->siglock); *** DEADLOCK *** 2 locks held by syz-executor.1/8723: #0: ffff8880b953ea58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559 #1: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #1: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x107/0x460 kernel/trace/bpf_trace.c:2422 stack backtrace: CPU: 1 PID: 8723 Comm: syz-executor.1 Not tainted 6.9.0-rc6-syzkaller-00113-g49a73b1652c5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 force_sig_info_to_task+0x7a/0x660 kernel/signal.c:1334 force_sig_fault_to_task kernel/signal.c:1733 [inline] force_sig_fault+0xc5/0x110 kernel/signal.c:1738 kernelmode_fixup_or_oops+0x209/0x2b0 arch/x86/mm/fault.c:750 __bad_area_nosemaphore+0x39f/0x6b0 arch/x86/mm/fault.c:814 do_user_addr_fault+0x557/0x1080 arch/x86/mm/fault.c:1298 handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1563 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:rep_movs_alternative+0x13/0x70 arch/x86/lib/copy_user_64.S:43 Code: cc cc cc 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 83 f9 40 73 40 83 f9 08 73 21 85 c9 74 0f <8a> 06 88 07 48 ff c7 48 ff c6 48 ff c9 75 f1 c3 cc cc cc cc 66 0f RSP: 0000:ffffc90003307750 EFLAGS: 00050046 RAX: 00000000000051af RBX: 0000000000000008 RCX: 0000000000000008 RDX: 0000000000040000 RSI: 0000000000000000 RDI: ffffc90003307838 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000002 R10: 0000000000000002 R11: 0000000000000001 R12: ffffc90003307838 R13: ffff888021b20000 R14: 0000000000000000 R15: 0000000000000000 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:125 [inline] __copy_from_user_inatomic include/linux/uaccess.h:87 [inline] copy_from_user_nofault+0xe1/0x170 mm/maccess.c:125 bpf_probe_read_user_common kernel/trace/bpf_trace.c:179 [inline] ____bpf_probe_read_user kernel/trace/bpf_trace.c:188 [inline] bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:185 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:1997 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2236 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run4+0x176/0x460 kernel/trace/bpf_trace.c:2422 __bpf_trace_sched_switch+0x13e/0x190 include/trace/events/sched.h:222 __traceiter_sched_switch+0x6c/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x252c/0x5d00 kernel/sched/core.c:6743 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7068 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__seqprop_raw_spinlock_sequence include/linux/seqlock.h:226 [inline] RIP: 0010:ktime_get_real_ts64+0xbf/0x570 kernel/time/timekeeping.c:824 Code: 24 58 48 c7 c7 48 da 7d 8d e8 dd 19 f0 ff 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 ab fa 11 00 48 85 db 58 0f 85 3a 04 00 00 8c ff 11 00 eb 07 e8 85 ff 11 00 f3 90 8b 2d 8d 13 02 0c 31 ff RSP: 0000:ffffc90003307d88 EFLAGS: 00000283 RAX: 000000000000516b RBX: 0000000000000000 RCX: ffffc90013400000 RDX: 0000000000040000 RSI: ffffffff817bca99 RDI: 0000000000000007 RBP: 0000000000000019 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffc90003307e00 R13: 00007fcca1911c70 R14: dffffc0000000000 R15: ffff888021b20000 __do_sys_gettimeofday kernel/time/time.c:146 [inline] __se_sys_gettimeofday kernel/time/time.c:140 [inline] __x64_sys_gettimeofday+0xd4/0x210 kernel/time/time.c:140 emulate_vsyscall+0x4ea/0xe50 arch/x86/entry/vsyscall/vsyscall_64.c:247 do_user_addr_fault+0x61a/0x1080 arch/x86/mm/fault.c:1346 handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1563 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:_end+0x6a9da000/0x0 Code: Unable to access opcode bytes at 0xffffffffff5fffd6. RSP: 002b:00007fcca1911b38 EFLAGS: 00010246 RAX: ffffffffffffffda RBX: 00007fcca0dac050 RCX: 00007fcca0c7dea9 RDX: 00007fcca1911b40 RSI: 00007fcca1911c70 RDI: 0000000000000019 RBP: 00007fcca0cca4a4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007fcca0dac050 R15: 00007ffcc06f7cb8 ---------------- Code disassembly (best guess): 0: cc int3 1: cc int3 2: cc int3 3: 0f 1f 40 00 nopl 0x0(%rax) 7: 90 nop 8: 90 nop 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: f3 0f 1e fa endbr64 1b: 48 83 f9 40 cmp $0x40,%rcx 1f: 73 40 jae 0x61 21: 83 f9 08 cmp $0x8,%ecx 24: 73 21 jae 0x47 26: 85 c9 test %ecx,%ecx 28: 74 0f je 0x39 * 2a: 8a 06 mov (%rsi),%al <-- trapping instruction 2c: 88 07 mov %al,(%rdi) 2e: 48 ff c7 inc %rdi 31: 48 ff c6 inc %rsi 34: 48 ff c9 dec %rcx 37: 75 f1 jne 0x2a 39: c3 ret 3a: cc int3 3b: cc int3 3c: cc int3 3d: cc int3 3e: 66 data16 3f: 0f .byte 0xf