====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc5-syzkaller-00329-g5d12ed4bea43 #0 Not tainted ------------------------------------------------------ syz-executor.4/9478 is trying to acquire lock: ffff8880296ed358 (&sighand->siglock){-.-.}-{2:2}, at: __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414 but task is already holding lock: ffff8880b94387e8 (lock#12){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b94387e8 (lock#12){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (lock#12){+.+.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0xa8/0x630 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:166 [inline] stack_map_get_build_id_offset+0x9b2/0x9d0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1985 [inline] bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1975 bpf_prog_ec3b2eefa702d8d3+0x42/0x4a 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_run2+0x206/0x420 kernel/trace/bpf_trace.c:2420 trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x7cb/0xae0 context_switch kernel/sched/core.c:5393 [inline] __schedule+0x1066/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 do_nanosleep+0x197/0x600 kernel/time/hrtimer.c:2051 hrtimer_nanosleep+0x227/0x470 kernel/time/hrtimer.c:2104 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1396 [inline] __se_sys_clock_nanosleep+0x32d/0x3c0 kernel/time/posix-timers.c:1373 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2a/0x140 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_exit_signals+0x17b/0x4b0 kernel/sched/core.c:12005 exit_signals+0x2a1/0x5c0 kernel/signal.c:3016 do_exit+0x6a8/0x27e0 kernel/exit.c:837 __do_sys_exit kernel/exit.c:994 [inline] __se_sys_exit kernel/exit.c:992 [inline] __pfx___ia32_sys_exit+0x0/0x10 kernel/exit.c:992 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 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+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x274/0x310 kernel/signal.c:1453 bpf_send_signal_common+0x2dd/0x430 kernel/trace/bpf_trace.c:881 ____bpf_send_signal_thread kernel/trace/bpf_trace.c:898 [inline] bpf_send_signal_thread+0x16/0x20 kernel/trace/bpf_trace.c:896 bpf_prog_7bb747c56a8bcba8+0x1d/0x29 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+0x25c/0x490 kernel/trace/bpf_trace.c:2422 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x5c8/0x630 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:166 [inline] get_mmap_lock_carefully mm/memory.c:5633 [inline] lock_mm_and_find_vma+0x213/0x2f0 mm/memory.c:5693 do_user_addr_fault arch/x86/mm/fault.c:1385 [inline] handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x1a9/0x8e0 arch/x86/mm/fault.c:1563 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:131 [inline] copy_to_user_iter lib/iov_iter.c:25 [inline] iterate_ubuf include/linux/iov_iter.h:29 [inline] iterate_and_advance2 include/linux/iov_iter.h:245 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] _copy_to_iter+0x266/0x1960 lib/iov_iter.c:185 copy_page_to_iter+0xb1/0x160 lib/iov_iter.c:362 pipe_read+0x59c/0x13e0 fs/pipe.c:327 call_read_iter include/linux/fs.h:2104 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x97d/0xb70 fs/read_write.c:476 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &sighand->siglock --> &rq->__lock --> lock#12 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#12); lock(&rq->__lock); lock(lock#12); lock(&sighand->siglock); *** DEADLOCK *** 6 locks held by syz-executor.4/9478: #0: ffff888011b5e868 (&pipe->mutex){+.+.}-{3:3}, at: pipe_read+0x12a/0x13e0 fs/pipe.c:264 #1: ffff88801e6e4420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline] #1: ffff88801e6e4420 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5633 [inline] #1: ffff88801e6e4420 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5693 #2: ffff8880b94387e8 (lock#12){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #2: ffff8880b94387e8 (lock#12){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237 #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline] #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x600 mm/mmap_lock.c:209 #4: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #4: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16e/0x490 kernel/trace/bpf_trace.c:2422 #5: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #5: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #5: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x29/0x2e0 kernel/signal.c:1397 stack backtrace: CPU: 0 PID: 9478 Comm: syz-executor.4 Not tainted 6.9.0-rc5-syzkaller-00329-g5d12ed4bea43 #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+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 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+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x274/0x310 kernel/signal.c:1453 bpf_send_signal_common+0x2dd/0x430 kernel/trace/bpf_trace.c:881 ____bpf_send_signal_thread kernel/trace/bpf_trace.c:898 [inline] bpf_send_signal_thread+0x16/0x20 kernel/trace/bpf_trace.c:896 bpf_prog_7bb747c56a8bcba8+0x1d/0x29 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+0x25c/0x490 kernel/trace/bpf_trace.c:2422 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x5c8/0x630 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:166 [inline] get_mmap_lock_carefully mm/memory.c:5633 [inline] lock_mm_and_find_vma+0x213/0x2f0 mm/memory.c:5693 do_user_addr_fault arch/x86/mm/fault.c:1385 [inline] handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x1a9/0x8e0 arch/x86/mm/fault.c:1563 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] RIP: 0010:raw_copy_to_user arch/x86/include/asm/uaccess_64.h:131 [inline] RIP: 0010:copy_to_user_iter lib/iov_iter.c:25 [inline] RIP: 0010:iterate_ubuf include/linux/iov_iter.h:29 [inline] RIP: 0010:iterate_and_advance2 include/linux/iov_iter.h:245 [inline] RIP: 0010:iterate_and_advance include/linux/iov_iter.h:271 [inline] RIP: 0010:_copy_to_iter+0x266/0x1960 lib/iov_iter.c:185 Code: 82 25 03 00 00 e8 6a 0e e9 fc 4c 8b 7c 24 78 4c 89 ff 48 8b 5c 24 18 89 de e8 66 b0 4d fd 0f 01 cb 4c 89 ef 48 89 d9 4c 89 fe a4 0f 1f 00 0f 01 ca 48 29 cb 48 89 5c 24 18 49 bd 00 00 00 00 RSP: 0018:ffffc900031d78c0 EFLAGS: 00050256 RAX: ffffffff84acf001 RBX: 0000000000000040 RCX: 0000000000000040 RDX: 0000000000000000 RSI: ffff8880689ac000 RDI: 00007f898f5a8020 RBP: ffffc900031d7a38 R08: ffff8880689ac03f R09: 1ffff1100d135807 R10: dffffc0000000000 R11: ffffed100d135808 R12: 1ffff9200063afaf R13: 00007f898f5a8020 R14: ffffc900031d7d78 R15: ffff8880689ac000 copy_page_to_iter+0xb1/0x160 lib/iov_iter.c:362 pipe_read+0x59c/0x13e0 fs/pipe.c:327 call_read_iter include/linux/fs.h:2104 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x97d/0xb70 fs/read_write.c:476 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f898f47cb4c Code: ec 28 48 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 59 81 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 48 89 44 24 08 e8 af 81 02 00 48 RSP: 002b:00007ffe95a82fa0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f898f47cb4c RDX: 0000000000000040 RSI: 00007f898f5a8020 RDI: 00000000000000f9 RBP: 00007ffe95a8302c R08: 0000000000000000 R09: 0079746972756365 R10: 00007f898f57c6a0 R11: 0000000000000246 R12: 0000000000000032 R13: 0000000000064ee4 R14: 0000000000064b9f R15: 000000000000000c XFS (loop4): Unmounting Filesystem bfdc47fc-10d8-4eed-a562-11a831b3f791 EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000. ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 25 03 00 00 e8 and $0xe8000003,%eax 5: 6a 0e push $0xe 7: e9 fc 4c 8b 7c jmp 0x7c8b4d08 c: 24 78 and $0x78,%al e: 4c 89 ff mov %r15,%rdi 11: 48 8b 5c 24 18 mov 0x18(%rsp),%rbx 16: 89 de mov %ebx,%esi 18: e8 66 b0 4d fd call 0xfd4db083 1d: 0f 01 cb stac 20: 4c 89 ef mov %r13,%rdi 23: 48 89 d9 mov %rbx,%rcx 26: 4c 89 fe mov %r15,%rsi * 29: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2b: 0f 1f 00 nopl (%rax) 2e: 0f 01 ca clac 31: 48 29 cb sub %rcx,%rbx 34: 48 89 5c 24 18 mov %rbx,0x18(%rsp) 39: 49 rex.WB 3a: bd 00 00 00 00 mov $0x0,%ebp