===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 6.7.0-rc1-next-20231117-syzkaller #0 Not tainted ----------------------------------------------------- syz-executor.3/6401 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffff888031789298 (&sighand->siglock){+.+.}-{2:2}, at: __lock_task_sighand+0xc2/0x340 kernel/signal.c:1422 and this task is already holding: ffffffff8cff86b8 (css_set_lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] ffffffff8cff86b8 (css_set_lock){..-.}-{2:2}, at: cgroup_migrate_execute+0xd8/0x1230 kernel/cgroup/cgroup.c:2566 which would create a new lock dependency: (css_set_lock){..-.}-{2:2} -> (&sighand->siglock){+.+.}-{2:2} but this new dependency connects a SOFTIRQ-irq-safe lock: (css_set_lock){..-.}-{2:2} ... which became SOFTIRQ-irq-safe 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 put_css_set kernel/cgroup/cgroup-internal.h:208 [inline] put_css_set kernel/cgroup/cgroup-internal.h:196 [inline] cgroup_free+0x7c/0x1d0 kernel/cgroup/cgroup.c:6748 __put_task_struct+0x10b/0x3d0 kernel/fork.c:992 put_task_struct include/linux/sched/task.h:136 [inline] put_task_struct include/linux/sched/task.h:123 [inline] delayed_put_task_struct+0x22c/0x2d0 kernel/exit.c:227 rcu_do_batch kernel/rcu/tree.c:2158 [inline] rcu_core+0x828/0x16b0 kernel/rcu/tree.c:2431 __do_softirq+0x216/0x8d5 kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xb5/0x120 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 get_current arch/x86/include/asm/current.h:48 [inline] finish_task_switch.isra.0+0x220/0xcb0 kernel/sched/core.c:5273 context_switch kernel/sched/core.c:5402 [inline] __schedule+0xf1d/0x5c00 kernel/sched/core.c:6726 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7046 irqentry_exit+0x36/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 lock_acquire+0x1f2/0x530 kernel/locking/lockdep.c:5721 rcu_lock_acquire include/linux/rcupdate.h:301 [inline] rcu_read_lock include/linux/rcupdate.h:747 [inline] is_bpf_text_address+0x36/0x1a0 kernel/bpf/core.c:733 kernel_text_address kernel/extable.c:125 [inline] kernel_text_address+0x85/0xf0 kernel/extable.c:94 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x78/0xe0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xbe/0x170 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x24/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:763 [inline] slab_alloc_node mm/slub.c:3452 [inline] slab_alloc mm/slub.c:3460 [inline] __kmem_cache_alloc_lru mm/slub.c:3467 [inline] kmem_cache_alloc+0x163/0x300 mm/slub.c:3476 vma_lock_alloc kernel/fork.c:459 [inline] vm_area_dup+0x53/0x2f0 kernel/fork.c:512 dup_mmap kernel/fork.c:715 [inline] dup_mm kernel/fork.c:1709 [inline] copy_mm kernel/fork.c:1758 [inline] copy_process+0x560f/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 to a SOFTIRQ-irq-unsafe lock: (&sighand->siglock){+.+.}-{2:2} ... which became SOFTIRQ-irq-unsafe 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 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sighand->siglock); local_irq_disable(); lock(css_set_lock); lock(&sighand->siglock); lock(css_set_lock); *** DEADLOCK *** 8 locks held by syz-executor.3/6401: #0: ffff888026f439c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe7/0x170 fs/file.c:1177 #1: ffff88814d05e420 (sb_writers#10){.+.+}-{0:0}, at: do_writev+0x137/0x370 fs/read_write.c:976 #2: ffff88801f9fc088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x27d/0x500 fs/kernfs/file.c:325 #3: ffffffff8cff8768 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:368 [inline] #3: ffffffff8cff8768 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0x136/0x570 kernel/cgroup/cgroup.c:1662 #4: ffffffff8ce51f70 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2413 [inline] #4: ffffffff8ce51f70 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x18f/0x660 kernel/cgroup/cgroup.c:2917 #5: ffffffff8cff8530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2415 [inline] #5: ffffffff8cff8530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2411 [inline] #5: ffffffff8cff8530 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x19b/0x660 kernel/cgroup/cgroup.c:2917 #6: ffffffff8cff86b8 (css_set_lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] #6: ffffffff8cff86b8 (css_set_lock){..-.}-{2:2}, at: cgroup_migrate_execute+0xd8/0x1230 kernel/cgroup/cgroup.c:2566 #7: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #7: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #7: ffffffff8cfad060 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x3f/0x340 kernel/signal.c:1405 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (css_set_lock){..-.}-{2:2} { IN-SOFTIRQ-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 put_css_set kernel/cgroup/cgroup-internal.h:208 [inline] put_css_set kernel/cgroup/cgroup-internal.h:196 [inline] cgroup_free+0x7c/0x1d0 kernel/cgroup/cgroup.c:6748 __put_task_struct+0x10b/0x3d0 kernel/fork.c:992 put_task_struct include/linux/sched/task.h:136 [inline] put_task_struct include/linux/sched/task.h:123 [inline] delayed_put_task_struct+0x22c/0x2d0 kernel/exit.c:227 rcu_do_batch kernel/rcu/tree.c:2158 [inline] rcu_core+0x828/0x16b0 kernel/rcu/tree.c:2431 __do_softirq+0x216/0x8d5 kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xb5/0x120 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 get_current arch/x86/include/asm/current.h:48 [inline] finish_task_switch.isra.0+0x220/0xcb0 kernel/sched/core.c:5273 context_switch kernel/sched/core.c:5402 [inline] __schedule+0xf1d/0x5c00 kernel/sched/core.c:6726 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7046 irqentry_exit+0x36/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 lock_acquire+0x1f2/0x530 kernel/locking/lockdep.c:5721 rcu_lock_acquire include/linux/rcupdate.h:301 [inline] rcu_read_lock include/linux/rcupdate.h:747 [inline] is_bpf_text_address+0x36/0x1a0 kernel/bpf/core.c:733 kernel_text_address kernel/extable.c:125 [inline] kernel_text_address+0x85/0xf0 kernel/extable.c:94 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x78/0xe0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xbe/0x170 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x24/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:763 [inline] slab_alloc_node mm/slub.c:3452 [inline] slab_alloc mm/slub.c:3460 [inline] __kmem_cache_alloc_lru mm/slub.c:3467 [inline] kmem_cache_alloc+0x163/0x300 mm/slub.c:3476 vma_lock_alloc kernel/fork.c:459 [inline] vm_area_dup+0x53/0x2f0 kernel/fork.c:512 dup_mmap kernel/fork.c:715 [inline] dup_mm kernel/fork.c:1709 [inline] copy_mm kernel/fork.c:1758 [inline] copy_process+0x560f/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_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] cgroup_setup_root+0x62c/0xa00 kernel/cgroup/cgroup.c:2138 cgroup_init+0x23f/0x1100 kernel/cgroup/cgroup.c:6120 start_kernel+0x385/0x480 init/main.c:1063 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:555 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:536 secondary_startup_64_no_verify+0x166/0x16b } ... key at: [] css_set_lock+0x18/0x60 the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe 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: [] __key.341+0x0/0x40 ... acquired 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 __lock_task_sighand+0xc2/0x340 kernel/signal.c:1422 lock_task_sighand include/linux/sched/signal.h:748 [inline] cgroup_freeze_task+0x80/0x190 kernel/cgroup/freezer.c:160 cgroup_freezer_migrate_task+0x1b7/0x3a0 kernel/cgroup/freezer.c:257 cgroup_migrate_execute+0x2d3/0x1230 kernel/cgroup/cgroup.c:2580 cgroup_attach_task+0x5a8/0x8e0 kernel/cgroup/cgroup.c:2888 __cgroup_procs_write+0x311/0x540 kernel/cgroup/cgroup.c:5196 cgroup_procs_write+0x26/0x50 kernel/cgroup/cgroup.c:5209 cgroup_file_write+0x209/0x7c0 kernel/cgroup/cgroup.c:4092 kernfs_fop_write_iter+0x33f/0x500 fs/kernfs/file.c:334 call_write_iter include/linux/fs.h:2021 [inline] do_iter_readv_writev+0x21d/0x3c0 fs/read_write.c:735 do_iter_write+0x17f/0x7f0 fs/read_write.c:860 vfs_writev+0x221/0x700 fs/read_write.c:933 do_writev+0x137/0x370 fs/read_write.c:976 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: 6401 Comm: syz-executor.3 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: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_bad_irq_dependency kernel/locking/lockdep.c:2626 [inline] check_irq_usage+0xe18/0x1470 kernel/locking/lockdep.c:2865 check_prev_add kernel/locking/lockdep.c:3138 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x247c/0x3b10 kernel/locking/lockdep.c:5136 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 __lock_task_sighand+0xc2/0x340 kernel/signal.c:1422 lock_task_sighand include/linux/sched/signal.h:748 [inline] cgroup_freeze_task+0x80/0x190 kernel/cgroup/freezer.c:160 cgroup_freezer_migrate_task+0x1b7/0x3a0 kernel/cgroup/freezer.c:257 cgroup_migrate_execute+0x2d3/0x1230 kernel/cgroup/cgroup.c:2580 cgroup_attach_task+0x5a8/0x8e0 kernel/cgroup/cgroup.c:2888 __cgroup_procs_write+0x311/0x540 kernel/cgroup/cgroup.c:5196 cgroup_procs_write+0x26/0x50 kernel/cgroup/cgroup.c:5209 cgroup_file_write+0x209/0x7c0 kernel/cgroup/cgroup.c:4092 kernfs_fop_write_iter+0x33f/0x500 fs/kernfs/file.c:334 call_write_iter include/linux/fs.h:2021 [inline] do_iter_readv_writev+0x21d/0x3c0 fs/read_write.c:735 do_iter_write+0x17f/0x7f0 fs/read_write.c:860 vfs_writev+0x221/0x700 fs/read_write.c:933 do_writev+0x137/0x370 fs/read_write.c:976 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: 0033:0x7f58d527cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f58d5f5e0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f58d539bf80 RCX: 00007f58d527cae9 RDX: 0000000000000001 RSI: 00000000200001c0 RDI: 0000000000000004 RBP: 00007f58d52c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f58d539bf80 R15: 00007fffe3004ab8