------------[ cut here ]------------ ====================================================== WARNING: possible circular locking dependency detected 6.13.0-rc6-syzkaller-00059-g643e2e259c2b #0 Not tainted ------------------------------------------------------ syz.5.1291/11936 is trying to acquire lock: ffffffff8dda89f8 ((console_sem).lock){-...}-{2:2}, at: down_trylock+0x12/0x70 kernel/locking/semaphore.c:139 but task is already holding lock: ffff8880b863ed18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:606 [inline] ffff8880b863ed18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:591 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&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:598 raw_spin_rq_lock kernel/sched/sched.h:1523 [inline] task_rq_lock+0xcf/0x3b0 kernel/sched/core.c:700 cgroup_move_task+0x82/0x250 kernel/sched/psi.c:1161 css_set_move_task+0x288/0x5f0 kernel/cgroup/cgroup.c:898 cgroup_post_fork+0x1c6/0x910 kernel/cgroup/cgroup.c:6691 copy_process+0x578d/0x6f20 kernel/fork.c:2620 kernel_clone+0xfd/0x960 kernel/fork.c:2806 user_mode_thread+0xb4/0xf0 kernel/fork.c:2884 rest_init+0x23/0x2b0 init/main.c:712 start_kernel+0x3e4/0x4d0 init/main.c:1102 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x148 -> #1 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline] try_to_wake_up+0xb6/0x1490 kernel/sched/core.c:4205 up+0x79/0xb0 kernel/locking/semaphore.c:191 __up_console_sem+0x85/0xe0 kernel/printk/printk.c:343 __console_unlock kernel/printk/printk.c:2869 [inline] __console_flush_and_unlock kernel/printk/printk.c:3271 [inline] console_unlock+0x1dc/0x210 kernel/printk/printk.c:3309 do_con_write+0x14b0/0x7d00 drivers/tty/vt/vt.c:3105 con_write+0x23/0xb0 drivers/tty/vt/vt.c:3434 process_output_block drivers/tty/n_tty.c:574 [inline] n_tty_write+0x419/0x1140 drivers/tty/n_tty.c:2389 iterate_tty_write drivers/tty/tty_io.c:1015 [inline] file_tty_write.constprop.0+0x506/0x9a0 drivers/tty/tty_io.c:1090 tty_write drivers/tty/tty_io.c:1111 [inline] redirected_tty_write drivers/tty/tty_io.c:1134 [inline] redirected_tty_write+0xcc/0x140 drivers/tty/tty_io.c:1114 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x5ae/0x1150 fs/read_write.c:679 ksys_write+0x12b/0x250 fs/read_write.c:731 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 ((console_sem).lock){-...}-{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_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 down_trylock+0x12/0x70 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x40/0x140 kernel/printk/printk.c:326 console_trylock kernel/printk/printk.c:2852 [inline] console_trylock_spinning kernel/printk/printk.c:2009 [inline] vprintk_emit+0x3e3/0x6f0 kernel/printk/printk.c:2431 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:86 _printk+0xc8/0x100 kernel/printk/printk.c:2457 __report_bug lib/bug.c:195 [inline] report_bug+0x433/0x580 lib/bug.c:219 handle_bug+0x54/0xa0 arch/x86/kernel/traps.c:285 exc_invalid_op+0x17/0x50 arch/x86/kernel/traps.c:309 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621 lockdep_assert_rq_held kernel/sched/sched.h:1514 [inline] lockdep_assert_rq_held kernel/sched/sched.h:1512 [inline] update_rq_clock+0xe4/0xaa0 kernel/sched/core.c:793 pick_next_task kernel/sched/core.c:6212 [inline] __schedule+0x2683/0x5ad0 kernel/sched/core.c:6709 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7078 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709 lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5926 lock_is_held include/linux/lockdep.h:249 [inline] __might_resched+0x473/0x5e0 kernel/sched/core.c:8720 dump_user_range+0x4be/0x8c0 fs/coredump.c:954 elf_core_dump+0x2787/0x3880 fs/binfmt_elf.c:2129 do_coredump+0x2dd5/0x43e0 fs/coredump.c:758 get_signal+0x23f3/0x2610 kernel/signal.c:3002 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617 other info that might help us debug this: Chain exists of: (console_sem).lock --> &p->pi_lock --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&p->pi_lock); lock(&rq->__lock); lock((console_sem).lock); *** DEADLOCK *** 2 locks held by syz.5.1291/11936: #0: ffff888071598420 (sb_writers#5){.+.+}-{0:0}, at: get_signal+0x23f3/0x2610 kernel/signal.c:3002 #1: ffff8880b863ed18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:606 [inline] #1: ffff8880b863ed18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:591 stack backtrace: CPU: 0 UID: 0 PID: 11936 Comm: syz.5.1291 Not tainted 6.13.0-rc6-syzkaller-00059-g643e2e259c2b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x41c/0x610 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_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 down_trylock+0x12/0x70 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x40/0x140 kernel/printk/printk.c:326 console_trylock kernel/printk/printk.c:2852 [inline] console_trylock_spinning kernel/printk/printk.c:2009 [inline] vprintk_emit+0x3e3/0x6f0 kernel/printk/printk.c:2431 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:86 _printk+0xc8/0x100 kernel/printk/printk.c:2457 __report_bug lib/bug.c:195 [inline] report_bug+0x433/0x580 lib/bug.c:219 handle_bug+0x54/0xa0 arch/x86/kernel/traps.c:285 exc_invalid_op+0x17/0x50 arch/x86/kernel/traps.c:309 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621 RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1514 [inline] RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1512 [inline] RIP: 0010:update_rq_clock+0xe4/0xaa0 kernel/sched/core.c:793 Code: 02 84 c0 74 08 3c 03 0f 8e 9e 03 00 00 f6 83 30 0b 00 00 02 74 19 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 90 <0f> 0b 90 eb b6 4c 8d ab d8 0b 00 00 48 b8 00 00 00 00 00 fc ff df RSP: 0018:ffffc9000bc4f148 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff8880b873ed00 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8b4cd600 RDI: ffffffff8bb17080 RBP: ffffc9000bc4f328 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff901d1e14 R13: ffff88801cedda00 R14: ffff8880b873ed00 R15: ffff8880b863f808 pick_next_task kernel/sched/core.c:6212 [inline] __schedule+0x2683/0x5ad0 kernel/sched/core.c:6709 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7078 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709 RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5926 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 0c 31 e8 74 83 f8 01 75 2d 9c 58 f6 c4 02 75 43 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 45 31 ed eb RSP: 0018:ffffc9000bc4f408 EFLAGS: 00000282 RAX: 0000000000000046 RBX: ffff888027378ae0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8b4cd600 RDI: ffffffff8bb17080 RBP: ffffffff8ddbace0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888027378000 R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000001 lock_is_held include/linux/lockdep.h:249 [inline] __might_resched+0x473/0x5e0 kernel/sched/core.c:8720 dump_user_range+0x4be/0x8c0 fs/coredump.c:954 elf_core_dump+0x2787/0x3880 fs/binfmt_elf.c:2129 do_coredump+0x2dd5/0x43e0 fs/coredump.c:758 get_signal+0x23f3/0x2610 kernel/signal.c:3002 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617 RIP: 0033:0x7fcb96985d31 Code: 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:0000000020000000 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fcb96b75fa0 RCX: 00007fcb96985d29 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000040100000 RBP: 00007fcb96a01b08 R08: 0000000020000100 R09: 0000000020000100 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fcb96b75fa0 R15: 00007ffc135494e8 WARNING: CPU: 0 PID: 11936 at kernel/sched/sched.h:1514 lockdep_assert_rq_held kernel/sched/sched.h:1514 [inline] WARNING: CPU: 0 PID: 11936 at kernel/sched/sched.h:1514 lockdep_assert_rq_held kernel/sched/sched.h:1512 [inline] WARNING: CPU: 0 PID: 11936 at kernel/sched/sched.h:1514 update_rq_clock+0xe4/0xaa0 kernel/sched/core.c:793 Modules linked in: CPU: 0 UID: 0 PID: 11936 Comm: syz.5.1291 Not tainted 6.13.0-rc6-syzkaller-00059-g643e2e259c2b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1514 [inline] RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1512 [inline] RIP: 0010:update_rq_clock+0xe4/0xaa0 kernel/sched/core.c:793 Code: 02 84 c0 74 08 3c 03 0f 8e 9e 03 00 00 f6 83 30 0b 00 00 02 74 19 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 90 <0f> 0b 90 eb b6 4c 8d ab d8 0b 00 00 48 b8 00 00 00 00 00 fc ff df RSP: 0018:ffffc9000bc4f148 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff8880b873ed00 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8b4cd600 RDI: ffffffff8bb17080 RBP: ffffc9000bc4f328 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff901d1e14 R13: ffff88801cedda00 R14: ffff8880b873ed00 R15: ffff8880b863f808 FS: 00007fcb977e76c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdc3aea5000 CR3: 000000006007e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pick_next_task kernel/sched/core.c:6212 [inline] __schedule+0x2683/0x5ad0 kernel/sched/core.c:6709 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7078 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709 RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5926 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 0c 31 e8 74 83 f8 01 75 2d 9c 58 f6 c4 02 75 43 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 45 31 ed eb RSP: 0018:ffffc9000bc4f408 EFLAGS: 00000282 RAX: 0000000000000046 RBX: ffff888027378ae0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8b4cd600 RDI: ffffffff8bb17080 RBP: ffffffff8ddbace0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888027378000 R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000001 lock_is_held include/linux/lockdep.h:249 [inline] __might_resched+0x473/0x5e0 kernel/sched/core.c:8720 dump_user_range+0x4be/0x8c0 fs/coredump.c:954 elf_core_dump+0x2787/0x3880 fs/binfmt_elf.c:2129 do_coredump+0x2dd5/0x43e0 fs/coredump.c:758 get_signal+0x23f3/0x2610 kernel/signal.c:3002 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617 RIP: 0033:0x7fcb96985d31 Code: 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:0000000020000000 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fcb96b75fa0 RCX: 00007fcb96985d29 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000040100000 RBP: 00007fcb96a01b08 R08: 0000000020000100 R09: 0000000020000100 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fcb96b75fa0 R15: 00007ffc135494e8 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: b8 ff ff ff ff mov $0xffffffff,%eax 7: 65 0f c1 05 0c 31 e8 xadd %eax,%gs:0x74e8310c(%rip) # 0x74e8311b e: 74 f: 83 f8 01 cmp $0x1,%eax 12: 75 2d jne 0x41 14: 9c pushf 15: 58 pop %rax 16: f6 c4 02 test $0x2,%ah 19: 75 43 jne 0x5e 1b: 48 f7 04 24 00 02 00 testq $0x200,(%rsp) 22: 00 23: 74 01 je 0x26 25: fb sti 26: 48 83 c4 08 add $0x8,%rsp * 2a: 44 89 e8 mov %r13d,%eax <-- trapping instruction 2d: 5b pop %rbx 2e: 5d pop %rbp 2f: 41 5c pop %r12 31: 41 5d pop %r13 33: 41 5e pop %r14 35: 41 5f pop %r15 37: c3 ret 38: cc int3 39: cc int3 3a: cc int3 3b: cc int3 3c: 45 31 ed xor %r13d,%r13d 3f: eb .byte 0xeb