===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected 6.8.0-syzkaller-05236-g443574b03387 #0 Not tainted ----------------------------------------------------- syz-fuzzer/5071 [HC0[0]:SC0[2]:HE0:SE0] is trying to acquire: ffff888061e2a468 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888061e2a468 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939 and this task is already holding: ffff888028da65d8 (&sighand->siglock){-.-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] ffff888028da65d8 (&sighand->siglock){-.-.}-{2:2}, at: get_signal+0x247/0x1850 kernel/signal.c:2699 which would create a new lock dependency: (&sighand->siglock){-.-.}-{2:2} -> (&htab->buckets[i].lock){+.-.}-{2:2} but this new dependency connects a HARDIRQ-irq-safe lock: (&sighand->siglock){-.-.}-{2:2} ... which became HARDIRQ-irq-safe at: lock_acquire+0x1e4/0x530 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 do_bpf_send_signal+0x85/0x190 kernel/trace/bpf_trace.c:838 irq_work_single+0xe2/0x240 kernel/irq_work.c:221 irq_work_run_list kernel/irq_work.c:252 [inline] irq_work_run+0x18b/0x350 kernel/irq_work.c:261 __sysvec_irq_work+0xa8/0x3e0 arch/x86/kernel/irq_work.c:22 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x9e/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x156e/0x1850 kernel/signal.c:2910 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] irqentry_exit_to_user_mode+0x79/0x270 kernel/entry/common.c:225 exc_general_protection+0x410/0x5d0 arch/x86/kernel/traps.c:644 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617 to a HARDIRQ-irq-unsafe lock: (&htab->buckets[i].lock){+.-.}-{2:2} ... which became HARDIRQ-irq-unsafe at: ... lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_hash_free+0x164/0x820 net/core/sock_map.c:1154 bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&htab->buckets[i].lock); local_irq_disable(); lock(&sighand->siglock); lock(&htab->buckets[i].lock); lock(&sighand->siglock); *** DEADLOCK *** 2 locks held by syz-fuzzer/5071: #0: ffff888028da65d8 (&sighand->siglock){-.-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] #0: ffff888028da65d8 (&sighand->siglock){-.-.}-{2:2}, at: get_signal+0x247/0x1850 kernel/signal.c:2699 #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x14a/0x460 kernel/trace/bpf_trace.c:2421 the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (&sighand->siglock){-.-.}-{2:2} { IN-HARDIRQ-W at: lock_acquire+0x1e4/0x530 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 do_bpf_send_signal+0x85/0x190 kernel/trace/bpf_trace.c:838 irq_work_single+0xe2/0x240 kernel/irq_work.c:221 irq_work_run_list kernel/irq_work.c:252 [inline] irq_work_run+0x18b/0x350 kernel/irq_work.c:261 __sysvec_irq_work+0xa8/0x3e0 arch/x86/kernel/irq_work.c:22 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x9e/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x156e/0x1850 kernel/signal.c:2910 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] irqentry_exit_to_user_mode+0x79/0x270 kernel/entry/common.c:225 exc_general_protection+0x410/0x5d0 arch/x86/kernel/traps.c:644 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617 IN-SOFTIRQ-W at: lock_acquire+0x1e4/0x530 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 kernel/trace/bpf_trace.c:886 [inline] bpf_send_signal+0x19/0x30 kernel/trace/bpf_trace.c:884 0xffffffffa0001d8b 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+0x204/0x420 kernel/trace/bpf_trace.c:2420 trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0x291/0x380 mm/slub.c:4396 memcg_free_slab_cgroups mm/slub.c:1887 [inline] unaccount_slab mm/slub.c:2327 [inline] __free_slab+0xbd/0x270 mm/slub.c:2423 rcu_do_batch kernel/rcu/tree.c:2196 [inline] rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2471 __do_softirq+0x2bc/0x943 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 kasan_check_range+0x5/0x290 mm/kasan/generic.c:188 __asan_memset+0x23/0x50 mm/kasan/shadow.c:84 unwind_next_frame+0x13ab/0x2a00 arch/x86/kernel/unwind_orc.c:592 __unwind_start+0x641/0x7c0 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x103/0x1b0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:589 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4299 [inline] kmem_cache_free+0x102/0x2a0 mm/slub.c:4363 do_sys_openat2+0x17a/0x1d0 fs/open.c:1415 do_sys_open fs/open.c:1422 [inline] __do_sys_openat fs/open.c:1438 [inline] __se_sys_openat fs/open.c:1433 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1433 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 INITIAL USE at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [inline] calculate_sigpending+0x4f/0x90 kernel/signal.c:188 ret_from_fork+0x24/0x80 arch/x86/kernel/process.c:143 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 } ... key at: [] sighand_ctor.__key+0x0/0x20 the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock: -> (&htab->buckets[i].lock){+.-.}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_hash_free+0x164/0x820 net/core/sock_map.c:1154 bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 IN-SOFTIRQ-W at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939 0xffffffffa0001d8e 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+0x204/0x420 kernel/trace/bpf_trace.c:2420 trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0x291/0x380 mm/slub.c:4396 __bpf_prog_put_rcu+0x3b/0xd0 kernel/bpf/syscall.c:2232 rcu_do_batch kernel/rcu/tree.c:2196 [inline] rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2471 __do_softirq+0x2bc/0x943 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 variable_test_bit arch/x86/include/asm/bitops.h:227 [inline] arch_test_bit arch/x86/include/asm/bitops.h:239 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] tomoyo_check_acl+0x2d8/0x3f0 security/tomoyo/domain.c:184 tomoyo_path_permission+0x1af/0x360 security/tomoyo/file.c:586 tomoyo_path_perm+0x480/0x740 security/tomoyo/file.c:838 security_inode_getattr+0xd8/0x130 security/security.c:2238 vfs_getattr+0x45/0x430 fs/stat.c:173 vfs_statx+0x1a5/0x4e0 fs/stat.c:248 vfs_fstatat+0x135/0x190 fs/stat.c:304 __do_sys_newfstatat fs/stat.c:468 [inline] __se_sys_newfstatat fs/stat.c:462 [inline] __x64_sys_newfstatat+0x117/0x190 fs/stat.c:462 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 INITIAL USE at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_hash_free+0x164/0x820 net/core/sock_map.c:1154 bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 } ... key at: [] sock_hash_alloc.__key+0x0/0x20 ... acquired at: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939 bpf_prog_bc4ba9860fbb0da4+0x46/0x4a 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_run3+0x238/0x460 kernel/trace/bpf_trace.c:2421 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x23c/0x2a0 mm/slub.c:4362 __sigqueue_free kernel/signal.c:451 [inline] collect_signal kernel/signal.c:594 [inline] __dequeue_signal+0x4ac/0x5c0 kernel/signal.c:616 dequeue_signal+0x169/0x5a0 kernel/signal.c:639 get_signal+0x5f7/0x1850 kernel/signal.c:2787 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0xc9/0x360 kernel/entry/common.c:212 do_syscall_64+0x10a/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x6d/0x75 stack backtrace: CPU: 0 PID: 5071 Comm: syz-fuzzer Not tainted 6.8.0-syzkaller-05236-g443574b03387 #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+0x1e7/0x2e0 lib/dump_stack.c:106 print_bad_irq_dependency kernel/locking/lockdep.c:2626 [inline] check_irq_usage kernel/locking/lockdep.c:2865 [inline] check_prev_add kernel/locking/lockdep.c:3138 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x4dc7/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939 bpf_prog_bc4ba9860fbb0da4+0x46/0x4a 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_run3+0x238/0x460 kernel/trace/bpf_trace.c:2421 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x23c/0x2a0 mm/slub.c:4362 __sigqueue_free kernel/signal.c:451 [inline] collect_signal kernel/signal.c:594 [inline] __dequeue_signal+0x4ac/0x5c0 kernel/signal.c:616 dequeue_signal+0x169/0x5a0 kernel/signal.c:639 get_signal+0x5f7/0x1850 kernel/signal.c:2787 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0xc9/0x360 kernel/entry/common.c:212 do_syscall_64+0x10a/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x40720e Code: 48 83 ec 38 e8 13 00 00 00 48 83 c4 38 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 f2 48 89 fa 48 89 ce 48 89 df 0f 05 <48> 3d 01 f0 ff ff 76 15 48 f7 d8 48 89 c1 48 c7 c0 ff ff ff ff 48 RSP: 002b:000000c000057d80 EFLAGS: 00000216 ORIG_RAX: 0000000000000000 RAX: fffffffffffffff5 RBX: 0000000000000010 RCX: 000000000040720e RDX: 0000000000010000 RSI: 000000c000de2000 RDI: 0000000000000010 RBP: 000000c000057dc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000216 R12: 000000c000057f00 R13: 124c24c24c249209 R14: 000000c0004bbba0 R15: 0000000000000142