======================================================== WARNING: possible irq lock inversion dependency detected 6.7.0-rc1-next-20231117-syzkaller #0 Not tainted -------------------------------------------------------- syz-executor.2/5105 just changed the state of lock: ffff88801d02ebf8 (&new_timer->it_lock){-...}-{2:2}, at: posix_timer_fn+0x2d/0x3d0 kernel/time/posix-timers.c:318 but this lock took another, HARDIRQ-unsafe lock in the past: (&sighand->siglock){+.+.}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sighand->siglock); local_irq_disable(); lock(&new_timer->it_lock); lock(&sighand->siglock); <Interrupt> lock(&new_timer->it_lock); *** DEADLOCK *** 7 locks held by syz-executor.2/5105: #0: ffffffff8d0af1b0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:655 [inline] #0: ffffffff8d0af1b0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1709 [inline] #0: ffffffff8d0af1b0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm kernel/fork.c:1758 [inline] #0: ffffffff8d0af1b0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_process+0x42a6/0x9770 kernel/fork.c:2520 #1: ffff88807b66e0a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #1: ffff88807b66e0a0 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:656 [inline] #1: ffff88807b66e0a0 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1709 [inline] #1: ffff88807b66e0a0 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm kernel/fork.c:1758 [inline] #1: ffff88807b66e0a0 (&mm->mmap_lock){++++}-{3:3}, at: copy_process+0x42cc/0x9770 kernel/fork.c:2520 #2: ffff888028f181a0 (&mm->mmap_lock/1){+.+.}-{3:3}, at: mmap_write_lock_nested include/linux/mmap_lock.h:115 [inline] #2: ffff888028f181a0 (&mm->mmap_lock/1){+.+.}-{3:3}, at: dup_mmap kernel/fork.c:665 [inline] #2: ffff888028f181a0 (&mm->mmap_lock/1){+.+.}-{3:3}, at: dup_mm kernel/fork.c:1709 [inline] #2: ffff888028f181a0 (&mm->mmap_lock/1){+.+.}-{3:3}, at: copy_mm kernel/fork.c:1758 [inline] #2: ffff888028f181a0 (&mm->mmap_lock/1){+.+.}-{3:3}, at: copy_process+0x432c/0x9770 kernel/fork.c:2520 #3: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #3: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #3: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: __pte_offset_map+0x42/0x540 mm/pgtable-generic.c:285 #4: ffff888079231858 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #4: ffff888079231858 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: __pte_offset_map_lock+0xf1/0x2f0 mm/pgtable-generic.c:373 #5: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #5: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #5: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: __pte_offset_map+0x42/0x540 mm/pgtable-generic.c:285 #6: ffff888029246618 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_pte_range mm/memory.c:1052 [inline] #6: ffff888029246618 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_pmd_range mm/memory.c:1180 [inline] #6: ffff888029246618 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_pud_range mm/memory.c:1217 [inline] #6: ffff888029246618 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_p4d_range mm/memory.c:1241 [inline] #6: ffff888029246618 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_page_range+0xd1c/0x3c40 mm/memory.c:1339 the shortest dependencies between 2nd lock and 1st lock: -> (&sighand->siglock){+.+.}-{2:2} { HARDIRQ-ON-W at: lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] class_spinlock_constructor include/linux/spinlock.h:530 [inline] ptrace_set_stopped kernel/ptrace.c:391 [inline] ptrace_attach+0x401/0x650 kernel/ptrace.c:478 __do_sys_ptrace+0x204/0x230 kernel/ptrace.c:1290 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a SOFTIRQ-ON-W at: lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] class_spinlock_constructor include/linux/spinlock.h:530 [inline] ptrace_set_stopped kernel/ptrace.c:391 [inline] ptrace_attach+0x401/0x650 kernel/ptrace.c:478 __do_sys_ptrace+0x204/0x230 kernel/ptrace.c:1290 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [inline] calculate_sigpending+0x44/0xa0 kernel/signal.c:197 ret_from_fork+0x23/0x80 arch/x86/kernel/process.c:143 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 } ... key at: [<ffffffff90b4af80>] __key.341+0x0/0x40 ... acquired at: __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __do_sys_timer_delete kernel/time/posix-timers.c:1023 [inline] __se_sys_timer_delete kernel/time/posix-timers.c:1006 [inline] __x64_sys_timer_delete+0x16a/0x3e0 kernel/time/posix-timers.c:1006 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a -> (&new_timer->it_lock){-...}-{2:2} { IN-HARDIRQ-W at: lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 posix_timer_fn+0x2d/0x3d0 kernel/time/posix-timers.c:318 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x20c/0xc20 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x10c/0x410 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 check_kcov_mode kernel/kcov.c:175 [inline] write_comp_data+0x34/0x80 kernel/kcov.c:236 mm_counter_file include/linux/mm.h:2600 [inline] copy_present_pte mm/memory.c:967 [inline] copy_pte_range mm/memory.c:1095 [inline] copy_pmd_range mm/memory.c:1180 [inline] copy_pud_range mm/memory.c:1217 [inline] copy_p4d_range mm/memory.c:1241 [inline] copy_page_range+0x1022/0x3c40 mm/memory.c:1339 dup_mmap kernel/fork.c:765 [inline] dup_mm kernel/fork.c:1709 [inline] copy_mm kernel/fork.c:1758 [inline] copy_process+0x5c30/0x9770 kernel/fork.c:2520 kernel_clone+0xfd/0x940 kernel/fork.c:2925 __do_sys_clone+0xba/0x100 kernel/fork.c:3068 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 itimer_delete kernel/time/posix-timers.c:1048 [inline] exit_itimers+0x255/0x560 kernel/time/posix-timers.c:1109 do_exit+0x629/0x2ad0 kernel/exit.c:845 do_group_exit+0xd3/0x2a0 kernel/exit.c:1021 get_signal+0x2395/0x2770 kernel/signal.c:2902 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11e/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1e/0x60 kernel/entry/common.c:296 do_syscall_64+0x4d/0x110 arch/x86/entry/common.c:88 entry_SYSCALL_64_after_hwframe+0x62/0x6a } ... key at: [<ffffffff9280bea0>] __key.0+0x0/0x40 ... acquired at: mark_usage kernel/locking/lockdep.c:4563 [inline] __lock_acquire+0x1347/0x3b10 kernel/locking/lockdep.c:5090 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 posix_timer_fn+0x2d/0x3d0 kernel/time/posix-timers.c:318 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x20c/0xc20 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x10c/0x410 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 check_kcov_mode kernel/kcov.c:175 [inline] write_comp_data+0x34/0x80 kernel/kcov.c:236 mm_counter_file include/linux/mm.h:2600 [inline] copy_present_pte mm/memory.c:967 [inline] copy_pte_range mm/memory.c:1095 [inline] copy_pmd_range mm/memory.c:1180 [inline] copy_pud_range mm/memory.c:1217 [inline] copy_p4d_range mm/memory.c:1241 [inline] copy_page_range+0x1022/0x3c40 mm/memory.c:1339 dup_mmap kernel/fork.c:765 [inline] dup_mm kernel/fork.c:1709 [inline] copy_mm kernel/fork.c:1758 [inline] copy_process+0x5c30/0x9770 kernel/fork.c:2520 kernel_clone+0xfd/0x940 kernel/fork.c:2925 __do_sys_clone+0xba/0x100 kernel/fork.c:3068 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a stack backtrace: CPU: 1 PID: 5105 Comm: syz-executor.2 Not tainted 6.7.0-rc1-next-20231117-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_irq_inversion_bug.part.0+0x3e1/0x590 kernel/locking/lockdep.c:4079 print_irq_inversion_bug kernel/locking/lockdep.c:4032 [inline] check_usage_forwards kernel/locking/lockdep.c:4110 [inline] mark_lock_irq kernel/locking/lockdep.c:4242 [inline] mark_lock+0x570/0xc50 kernel/locking/lockdep.c:4677 mark_usage kernel/locking/lockdep.c:4563 [inline] __lock_acquire+0x1347/0x3b10 kernel/locking/lockdep.c:5090 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1b1/0x530 kernel/locking/lockdep.c:5718 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 posix_timer_fn+0x2d/0x3d0 kernel/time/posix-timers.c:318 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x20c/0xc20 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x10c/0x410 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1076 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:write_comp_data+0x34/0x80 kernel/kcov.c:236 Code: 48 8b 15 6f b3 7b 7e 65 8b 05 70 b3 7b 7e a9 00 01 ff 00 74 0f f6 c4 01 74 59 8b 82 fc 15 00 00 85 c0 74 4f 8b 82 d8 15 00 00 <83> f8 03 75 44 48 8b 82 e0 15 00 00 8b 92 dc 15 00 00 48 8b 38 48 RSP: 0018:ffffc90003d6f7d8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 800000002cadd007 RCX: ffffffff81ca24d2 RDX: ffff888026c45940 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffffea0000b2b740 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000007 R12: ffffea0000b2b740 R13: 0000000000000000 R14: dffffc0000000000 R15: ffff888035afbae8 mm_counter_file include/linux/mm.h:2600 [inline] copy_present_pte mm/memory.c:967 [inline] copy_pte_range mm/memory.c:1095 [inline] copy_pmd_range mm/memory.c:1180 [inline] copy_pud_range mm/memory.c:1217 [inline] copy_p4d_range mm/memory.c:1241 [inline] copy_page_range+0x1022/0x3c40 mm/memory.c:1339 dup_mmap kernel/fork.c:765 [inline] dup_mm kernel/fork.c:1709 [inline] copy_mm kernel/fork.c:1758 [inline] copy_process+0x5c30/0x9770 kernel/fork.c:2520 kernel_clone+0xfd/0x940 kernel/fork.c:2925 __do_sys_clone+0xba/0x100 kernel/fork.c:3068 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x62/0x6a RIP: 0033:0x7f7915679b13 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffe5424a408 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7915679b13 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000555556615750 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001 </TASK> ---------------- Code disassembly (best guess): 0: 48 8b 15 6f b3 7b 7e mov 0x7e7bb36f(%rip),%rdx # 0x7e7bb376 7: 65 8b 05 70 b3 7b 7e mov %gs:0x7e7bb370(%rip),%eax # 0x7e7bb37e e: a9 00 01 ff 00 test $0xff0100,%eax 13: 74 0f je 0x24 15: f6 c4 01 test $0x1,%ah 18: 74 59 je 0x73 1a: 8b 82 fc 15 00 00 mov 0x15fc(%rdx),%eax 20: 85 c0 test %eax,%eax 22: 74 4f je 0x73 24: 8b 82 d8 15 00 00 mov 0x15d8(%rdx),%eax * 2a: 83 f8 03 cmp $0x3,%eax <-- trapping instruction 2d: 75 44 jne 0x73 2f: 48 8b 82 e0 15 00 00 mov 0x15e0(%rdx),%rax 36: 8b 92 dc 15 00 00 mov 0x15dc(%rdx),%edx 3c: 48 8b 38 mov (%rax),%rdi 3f: 48 rex.W