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AFNElJ8LqNnfDvvAQJOEVFUhHcsOttMYqeudXbqzv34l50rtTyoRk7hD0/0Tp84SVzJCvmr8fAkN/Cw=@vger.kernel.org X-Gm-Message-State: AOJu0YwrzCCQyP/iJF81hgCnQEpg7d0CXRW2iwiYSis2CKWrIe+yghJD nBVxaSJU1hLDqhBs4PqcikubQjquVoXC8SO/HPE5aW0XCQgx3HmBuDazHXPoz4Xv66BoEGc5H3u czq924xQBJoFEkea7+kEflQY9mx2ZZr2Nq7WRZR+IWsHLT7m/9rnUBN8r+mc= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4b03:b0:69d:f0e8:3226 with SMTP id 006d021491bc7-69e101a7414mr1977112eaf.10.1780171204972; Sat, 30 May 2026 13:00:04 -0700 (PDT) Date: Sat, 30 May 2026 13:00:04 -0700 In-Reply-To: <20260530115511.1352487-1-jhs@mojatatu.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a1b41c4.323e8352.141b09.0003.GAE@google.com> Subject: [syzbot ci] Re: net/sched: act_api: use RCU with deferred freeing for action lifecycle From: syzbot ci To: davem@davemloft.net, edumazet@google.com, horms@kernel.org, jhs@mojatatu.com, jiri@resnulli.us, kuba@kernel.org, kylebot@openai.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, security@kernel.org, victor@mojatatu.com, vladbu@nvidia.com Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot ci has tested the following series [v1] net/sched: act_api: use RCU with deferred freeing for action lifecycle https://lore.kernel.org/all/20260530115511.1352487-1-jhs@mojatatu.com * [PATCH net 1/1] net/sched: act_api: use RCU with deferred freeing for action lifecycle and found the following issues: * BUG: sleeping function called from invalid context in __tcf_chain_put * inconsistent lock state in tcf_mirred_release Full report is available here: https://ci.syzbot.org/series/526aa788-9a02-4038-b101-5daf4d3436a2 *** BUG: sleeping function called from invalid context in __tcf_chain_put tree: net URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net.git base: 78ef59e7a6459b16f8102e0ee1c718443323d1af arch: amd64 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 config: https://ci.syzbot.org/builds/46884a04-6831-455e-8868-d463d6e018db/config syz repro: https://ci.syzbot.org/findings/3fb6310c-78f8-44da-bd19-4acd582420fa/syz_repro BUG: sleeping function called from invalid context at kernel/locking/mutex.c:623 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 23, name: ksoftirqd/1 preempt_count: 100, expected: 0 RCU nest depth: 0, expected: 0 1 lock held by ksoftirqd/1/23: #0: ffffffff8e95ce00 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95ce00 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2611 [inline] #0: ffffffff8e95ce00 (rcu_callback){....}-{0:0}, at: rcu_core+0x751/0x1070 kernel/rcu/tree.c:2869 Preemption disabled at: [] softirq_handle_begin kernel/softirq.c:463 [inline] [] handle_softirqs+0xb0/0x840 kernel/softirq.c:598 CPU: 1 UID: 0 PID: 23 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 __might_resched+0x378/0x4d0 kernel/sched/core.c:9163 __mutex_lock_common kernel/locking/mutex.c:623 [inline] __mutex_lock+0x11c/0x1550 kernel/locking/mutex.c:820 __tcf_chain_put+0x60/0x820 net/sched/cls_api.c:694 free_tcf net/sched/act_api.c:130 [inline] tcf_action_cleanup net/sched/act_api.c:370 [inline] tcf_action_rcu_free+0x39d/0x440 net/sched/act_api.c:378 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1076 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= [ BUG: Invalid wait context ] syzkaller #0 Tainted: G W ----------------------------- ksoftirqd/1/23 is trying to lock: ffff888171e3b0b0 (&block->lock){+.+.}-{4:4}, at: __tcf_chain_put+0x60/0x820 net/sched/cls_api.c:694 other info that might help us debug this: context-{3:3} 1 lock held by ksoftirqd/1/23: #0: ffffffff8e95ce00 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95ce00 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2611 [inline] #0: ffffffff8e95ce00 (rcu_callback){....}-{0:0}, at: rcu_core+0x751/0x1070 kernel/rcu/tree.c:2869 stack backtrace: CPU: 1 UID: 0 PID: 23 Comm: ksoftirqd/1 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_lock_invalid_wait_context kernel/locking/lockdep.c:4830 [inline] check_wait_context kernel/locking/lockdep.c:4902 [inline] __lock_acquire+0xec1/0x2cf0 kernel/locking/lockdep.c:5187 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820 __tcf_chain_put+0x60/0x820 net/sched/cls_api.c:694 free_tcf net/sched/act_api.c:130 [inline] tcf_action_cleanup net/sched/act_api.c:370 [inline] tcf_action_rcu_free+0x39d/0x440 net/sched/act_api.c:378 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1076 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 BUG: sleeping function called from invalid context at kernel/locking/mutex.c:623 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/1 preempt_count: 101, expected: 0 RCU nest depth: 0, expected: 0 INFO: lockdep is turned off. Preemption disabled at: [<0000000000000000>] 0x0 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 __might_resched+0x378/0x4d0 kernel/sched/core.c:9163 __mutex_lock_common kernel/locking/mutex.c:623 [inline] __mutex_lock+0x11c/0x1550 kernel/locking/mutex.c:820 __tcf_chain_put+0x60/0x820 net/sched/cls_api.c:694 free_tcf net/sched/act_api.c:130 [inline] tcf_action_cleanup net/sched/act_api.c:370 [inline] tcf_action_rcu_free+0x39d/0x440 net/sched/act_api.c:378 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: 2b 7d 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 03 c2 1f 00 fb f4 7c f7 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 00000246 RAX: ffff8882a9286000 RBX: ffffffff819a857a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8c28b7c0 RDI: ffffffff819a857a RBP: ffffc90000197f10 R08: ffff88823c6339db R09: 1ffff110478c673b R10: dffffc0000000000 R11: ffffed10478c673c R12: 0000000000000001 R13: 1ffff1102c09e000 R14: 0000000000000001 R15: 1ffff1102c09e000 arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147 BUG: sleeping function called from invalid context at kernel/locking/mutex.c:623 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 5742, name: syz-executor preempt_count: 100, expected: 0 RCU nest depth: 0, expected: 0 INFO: lockdep is turned off. Preemption disabled at: [] softirq_handle_begin kernel/softirq.c:463 [inline] [] handle_softirqs+0xb0/0x840 kernel/softirq.c:598 CPU: 1 UID: 0 PID: 5742 Comm: syz-executor Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 __might_resched+0x378/0x4d0 kernel/sched/core.c:9163 __mutex_lock_common kernel/locking/mutex.c:623 [inline] __mutex_lock+0x11c/0x1550 kernel/locking/mutex.c:820 __tcf_chain_put+0x60/0x820 net/sched/cls_api.c:694 free_tcf net/sched/act_api.c:130 [inline] tcf_action_cleanup net/sched/act_api.c:370 [inline] tcf_action_rcu_free+0x39d/0x440 net/sched/act_api.c:378 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:qlink_to_object mm/kasan/quarantine.c:140 [inline] RIP: 0010:qlink_free mm/kasan/quarantine.c:145 [inline] RIP: 0010:qlist_free_all+0x6f/0x100 mm/kasan/quarantine.c:179 Code: 49 8b 44 04 08 89 c2 83 e2 01 48 ff ca 48 09 c2 48 21 ca 0f b6 42 33 c1 e0 18 3d 00 00 00 f5 49 0f 45 d5 4c 8b 62 08 49 8b 2f <49> 63 84 24 b8 00 00 00 49 29 c7 4c 89 e7 4c 89 fe e8 4b e4 ff ff RSP: 0018:ffffc90003e9f440 EFLAGS: 00000246 RAX: 00000000f5000000 RBX: ffffc90003e9f478 RCX: ffffea0005c84b40 RDX: ffffea0005c84b40 RSI: ffffea00044f5600 RDI: ffff88817212d150 RBP: ffff88817263e598 R08: 0000000000000000 R09: ffffffff82310b6e R10: dffffc0000000000 R11: fffffbfff2061c3f R12: ffff888160417b40 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88817212d150 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4570 [inline] slab_alloc_node mm/slub.c:4899 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_node_noprof+0x498/0x7c0 mm/slub.c:5302 kmalloc_node_noprof include/linux/slab.h:1081 [inline] __vmalloc_area_node mm/vmalloc.c:3857 [inline] __vmalloc_node_range_noprof+0x5ef/0x1750 mm/vmalloc.c:4064 __vmalloc_node_noprof mm/vmalloc.c:4124 [inline] vzalloc_noprof+0xb2/0xe0 mm/vmalloc.c:4202 alloc_counters+0x64/0x5d0 net/ipv4/netfilter/ip_tables.c:799 copy_entries_to_user net/ipv4/netfilter/ip_tables.c:821 [inline] get_entries net/ipv4/netfilter/ip_tables.c:1022 [inline] do_ipt_get_ctl+0xada/0x1240 net/ipv4/netfilter/ip_tables.c:1668 nf_getsockopt+0x26e/0x290 net/netfilter/nf_sockopt.c:116 ip_getsockopt+0x19e/0x230 net/ipv4/ip_sockglue.c:1777 do_sock_getsockopt+0x51d/0x7e0 net/socket.c:2487 __sys_getsockopt net/socket.c:2518 [inline] __do_sys_getsockopt net/socket.c:2525 [inline] __se_sys_getsockopt net/socket.c:2522 [inline] __x64_sys_getsockopt+0x1a4/0x240 net/socket.c:2522 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f326419e62a Code: 48 83 ec 10 89 d2 48 63 ff 45 31 c9 6a 2a 45 31 c0 31 c9 e8 d8 99 fb ff 48 83 c4 18 c3 0f 1f 00 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 e8 ff ff ff f7 RSP: 002b:00007ffd38f686c8 EFLAGS: 00000216 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007ffd38f68750 RCX: 00007f326419e62a RDX: 0000000000000041 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007ffd38f686ec R09: ff78736871746264 R10: 00007ffd38f68750 R11: 0000000000000216 R12: 00007f32643ecac0 R13: 00007ffd38f686ec R14: 0000000000000000 R15: 00007f32643ed180 BUG: sleeping function called from invalid context at kernel/locking/mutex.c:623 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 23, name: ksoftirqd/1 preempt_count: 100, expected: 0 RCU nest depth: 0, expected: 0 INFO: lockdep is turned off. Preemption disabled at: [] softirq_handle_begin kernel/softirq.c:463 [inline] [] handle_softirqs+0xb0/0x840 kernel/softirq.c:598 CPU: 1 UID: 0 PID: 23 Comm: ksoftirqd/1 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 __might_resched+0x378/0x4d0 kernel/sched/core.c:9163 __mutex_lock_common kernel/locking/mutex.c:623 [inline] __mutex_lock+0x11c/0x1550 kernel/locking/mutex.c:820 __tcf_chain_put+0x60/0x820 net/sched/cls_api.c:694 free_tcf net/sched/act_api.c:130 [inline] tcf_action_cleanup net/sched/act_api.c:370 [inline] tcf_action_rcu_free+0x39d/0x440 net/sched/act_api.c:378 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1076 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ---------------- Code disassembly (best guess): 0: 2b 7d 02 sub 0x2(%rbp),%edi 3: c3 ret 4: cc int3 5: cc int3 6: cc int3 7: cc int3 8: cc int3 9: cc int3 a: cc int3 b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: f3 0f 1e fa endbr64 1f: eb 07 jmp 0x28 21: 0f 00 2d 03 c2 1f 00 verw 0x1fc203(%rip) # 0x1fc22b 28: fb sti 29: f4 hlt * 2a: e9 7c f7 02 00 jmp 0x2f7ab <-- trapping instruction 2f: cc int3 30: cc int3 31: cc int3 32: cc int3 33: cc int3 34: cc int3 35: cc int3 36: cc int3 37: cc int3 38: cc int3 39: cc int3 3a: cc int3 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop *** inconsistent lock state in tcf_mirred_release tree: net URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net.git base: 78ef59e7a6459b16f8102e0ee1c718443323d1af arch: amd64 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 config: https://ci.syzbot.org/builds/46884a04-6831-455e-8868-d463d6e018db/config syz repro: https://ci.syzbot.org/findings/339567f1-aefa-440b-b74d-8584664a549d/syz_repro ================================ WARNING: inconsistent lock state syzkaller #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. ksoftirqd/1/23 [HC0[0]:SC1[1]:HE1:SE0] takes: ffffffff8fe24698 (mirred_list_lock){+.?.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline] ffffffff8fe24698 (mirred_list_lock){+.?.}-{3:3}, at: tcf_mirred_release+0x2c/0x1c0 net/sched/act_mirred.c:78 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 spin_lock include/linux/spinlock.h:342 [inline] mirred_device_event+0x80/0x2c0 net/sched/act_mirred.c:561 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] unregister_netdevice_many_notify+0x17a5/0x22c0 net/core/dev.c:12421 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] ops_undo_list+0x3d3/0x940 net/core/net_namespace.c:248 cleanup_net+0x56b/0x800 net/core/net_namespace.c:702 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 irq event stamp: 953728 hardirqs last enabled at (953728): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline] hardirqs last enabled at (953728): [] _raw_spin_unlock_irqrestore+0x30/0x80 kernel/locking/spinlock.c:198 hardirqs last disabled at (953727): [] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:130 [inline] hardirqs last disabled at (953727): [] _raw_spin_lock_irqsave+0x1a/0x60 kernel/locking/spinlock.c:166 softirqs last enabled at (953336): [] run_ksoftirqd+0x36/0x60 kernel/softirq.c:1076 softirqs last disabled at (953341): [] run_ksoftirqd+0x36/0x60 kernel/softirq.c:1076 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(mirred_list_lock); lock(mirred_list_lock); *** DEADLOCK *** 1 lock held by ksoftirqd/1/23: #0: ffffffff8e95ce00 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95ce00 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2611 [inline] #0: ffffffff8e95ce00 (rcu_callback){....}-{0:0}, at: rcu_core+0x751/0x1070 kernel/rcu/tree.c:2869 stack backtrace: CPU: 1 UID: 0 PID: 23 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_usage_bug+0x28b/0x2e0 kernel/locking/lockdep.c:4042 valid_state kernel/locking/lockdep.c:4056 [inline] mark_lock_irq+0x410/0x420 kernel/locking/lockdep.c:-1 mark_lock+0x115/0x190 kernel/locking/lockdep.c:4753 mark_usage kernel/locking/lockdep.c:-1 [inline] __lock_acquire+0x689/0x2cf0 kernel/locking/lockdep.c:5191 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 spin_lock include/linux/spinlock.h:342 [inline] tcf_mirred_release+0x2c/0x1c0 net/sched/act_mirred.c:78 tcf_action_cleanup net/sched/act_api.c:367 [inline] tcf_action_rcu_free+0x2bd/0x440 net/sched/act_api.c:378 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1076 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 *** If these findings have caused you to resend the series or submit a separate fix, please add the following tag to your commit message: Tested-by: syzbot@syzkaller.appspotmail.com --- This report is generated by a bot. 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