Hello, when fuzzing the Linux kernel, I triggered many "watch: BUG: soft lockup" warnings. I am not sure whether this is an issue with the kernel or with the fuzzing program I ran. (The same fuzzing program, when tested on kernel versions from Linux-6.7.0 to 6.12.0, triggers the 'watchdog: BUG: soft lockup' warning on some versions, while others do not. Linux 6.12.0 is the latest stable release where this error occurs.) The bug information I provided below is from the Linux-6.12.0 kernel. If you need bug information from other versions, I would be happy to provide it. kernel config :https://pastebin.com/i4LPXNAN console output :https://pastebin.com/uKVpvJ78 The beginning part of the crash report is as follows: [283539.715873] rcu: INFO: rcu_preempt self-detected stall on CPU [283540.766023] watchdog: BUG: soft lockup - CPU#9 stuck for 64s! [kworker/u515:2:86301] [283540.766046] Modules linked in: raw_gadget(OE) dummy_hcd(OE) snd_ctl_led hid_sensor_hub hid_multitouch udc_core veth xt_conntrack nft_chain_nat xt_MASQUERADE bridge stp llc nf_conntrack_netlink xfrm_user xfrm_algo xt_addrtype nft_compat nf_tables overlay nfnetlink_cttimeout nfnetlink bnep intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_core intel_vsec pmt_telemetry pmt_class openvswitch vsock_loopback vmw_vsock_virtio_transport_common nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 kvm_intel psample snd_ens1371 crct10dif_pclmul libcrc32c polyval_clmulni snd_ac97_codec vmw_vsock_vmci_transport polyval_generic vsock sunrpc binfmt_misc gameport ghash_clmulni_intel kvm sha256_ssse3 sha1_ssse3 ac97_bus vmw_balloon aesni_intel crypto_simd [283545.281916] rcu: 2-...!: (137 ticks this GP) idle=ecec/1/0x4000000000000000 softirq=11168967/11168969 fqs=0 [283545.291031] snd_pcm cryptd snd_seq_midi btusb snd_seq_midi_event btrtl rapl nls_iso8859_1 btintel snd_rawmidi btbcm btmtk snd_seq [283545.301366] rcu: (t=73327 jiffies g=69763773 q=104 ncpus=16) [283545.301387] rcu: rcu_preempt kthread timer wakeup didn't happen for 73324 jiffies! g69763773 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 [283545.307516] rcu: Possible timer handling issue on cpu=4 timer-softirq=4703160 [283545.308817] input_leds snd_seq_device joydev bluetooth snd_timer serio_raw snd soundcore vmw_vmci mac_hid sch_fq_codel vmwgfx drm_ttm_helper ttm msr parport_pc ppdev lp [283545.316000] rcu: rcu_preempt kthread starved for 73327 jiffies! g69763773 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=4 [283545.316032] rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. [283545.316035] rcu: RCU grace-period kthread stack dump: [283545.316038] task:rcu_preempt state:I [283545.779182] parport efi_pstore ip_tables x_tables autofs4 hid_generic crc32_pclmul [283545.783533] ------------[ cut here ]------------ [283545.785609] psmouse usbhid hid mptspi mptscsih i2c_piix4 ahci mptbase e1000 libahci scsi_transport_spi i2c_smbus pata_acpi [last unloaded: raw_gadget(OE)] [283545.789981] CPU: 9 UID: 0 PID: 86301 Comm: kworker/u515:2 Tainted: G OE 6.12.0 #1 [283545.790017] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE [283545.790019] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [283545.790027] Workqueue: events_freezable_pwr_efficient disk_events_workfn [283545.808817] stack:29152 pid:17 tgid:17 ppid:2 flags:0x00004000 [283545.808838] Call Trace: [283545.808843] <TASK> [283545.803556] RIP: 0010:_raw_spin_unlock_irqrestore+0x21/0x60 [283545.808853] __schedule+0xc0c/0x4ee0 [283545.841937] Code: 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 49 89 f0 48 89 e5 c6 07 00 0f 1f 00 41 f7 c0 00 02 00 00 74 06 fb 0f 1f 44 00 00 <65> ff 0d 20 8d e9 73 74 13 5d 31 c0 31 d2 31 c9 31 f6 31 ff 45 31 [283545.841978] RSP: 0018:ffffc900309af550 EFLAGS: 00000206 [283545.841988] RAX: dffffc0000000000 RBX: ffff888114cf4000 RCX: 0000000000000000 [283545.841992] RDX: 1ffff1102299e802 RSI: 0000000000000246 RDI: ffff888106bcd000 [283545.841995] RBP: ffffc900309af550 R08: 0000000000000246 R09: 0000000000000000 [283545.841997] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [283545.842001] R13: 0000000000000246 R14: ffff888114cf4010 R15: ffff88822caa4000 [283545.842005] FS: 0000000000000000(0000) GS:ffff88862ea80000(0000) knlGS:0000000000000000 [283545.846254] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [283545.787091] WARNING: CPU: 13 PID: 2974 at kernel/sched/deadline.c:1995 enqueue_dl_entity+0x167f/0x3300 [283545.812128] ? sched_clock_cpu+0x6a/0x520 [283545.847597] ? __kasan_check_write+0x14/0x30 [283545.847607] ? __pfx___schedule+0x10/0x10 [283545.847616] ? save_fpregs_to_fpstate+0xb0/0x230 [283545.847621] ? raw_spin_rq_unlock+0x17/0xa0 [283545.847627] schedule+0x83/0x350 [283545.847634] schedule_timeout+0x106/0x350 [283545.847640] ? __kasan_check_write+0x14/0x30 [283545.847639] Modules linked in: [283545.847644] ? __pfx_schedule_timeout+0x10/0x10 [283545.847647] raw_gadget(OE) [283545.847648] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [283545.847651] dummy_hcd(OE) snd_ctl_led [283545.847652] ? __pfx_process_timeout+0x10/0x10 [283545.847657] hid_sensor_hub hid_multitouch [283545.847659] ? __kasan_check_write+0x14/0x30 [283545.847664] ? prepare_to_swait_event+0xb8/0x350 [283545.847665] CR2: 00002a0000c65280 CR3: 000000011b16e000 CR4: 0000000000752ef0 [283545.847670] udc_core veth xt_conntrack nft_chain_nat xt_MASQUERADE bridge stp llc nf_conntrack_netlink xfrm_user xfrm_algo xt_addrtype nft_compat nf_tables overlay nfnetlink_cttimeout nfnetlink bnep intel_rapl_msr intel_rapl_common [283545.847709] PKRU: 55555554 [283545.847711] intel_uncore_frequency_common intel_pmc_core [283545.847715] Call Trace: [283545.847718] intel_vsec pmt_telemetry [283545.847720] <IRQ> [283545.847723] pmt_class openvswitch vsock_loopback vmw_vsock_virtio_transport_common nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 kvm_intel psample snd_ens1371 crct10dif_pclmul libcrc32c polyval_clmulni snd_ac97_codec vmw_vsock_vmci_transport polyval_generic vsock sunrpc binfmt_misc gameport ghash_clmulni_intel kvm sha256_ssse3 sha1_ssse3 ac97_bus vmw_balloon aesni_intel crypto_simd snd_pcm cryptd snd_seq_midi btusb snd_seq_midi_event btrtl rapl nls_iso8859_1 btintel snd_rawmidi btbcm btmtk snd_seq input_leds snd_seq_device joydev bluetooth snd_timer serio_raw snd soundcore vmw_vmci mac_hid sch_fq_codel vmwgfx drm_ttm_helper ttm msr parport_pc ppdev lp parport efi_pstore ip_tables x_tables autofs4 hid_generic crc32_pclmul psmouse usbhid hid mptspi mptscsih i2c_piix4 ahci mptbase e1000 libahci scsi_transport_spi i2c_smbus pata_acpi [last unloaded: raw_gadget(OE)] [283545.847881] CPU: 13 UID: 1000 PID: 2974 Comm: gsd-housekeepin Tainted: G OE 6.12.0 #1 [283545.847888] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE [283545.847891] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [283545.847895] RIP: 0010:enqueue_dl_entity+0x167f/0x3300 [283545.847901] Code: e8 f6 bb 8b 00 4c 8b 5d c8 4c 8b 55 d0 e9 18 f7 ff ff 85 c9 0f 84 51 fa ff ff 44 89 c6 4c 89 e7 e8 76 2b ff ff e9 41 fa ff ff <0f> 0b e9 bb e9 ff ff 0f 0b e9 c2 ef ff ff 48 b8 00 00 00 00 00 fc [283545.847905] RSP: 0018:ffffc90005fd6ce0 EFLAGS: 00010082 [283545.847909] RAX: dffffc0000000000 RBX: ffff88862ecc7ca8 RCX: 0000000000000001 [283545.847912] RDX: 1ffff110c5d98f95 RSI: 0000000000000001 RDI: ffff88862ecc7ca8 [283545.847915] RBP: ffffc90005fd6d40 R08: 0000000000000001 R09: 0000000000000000 [283545.847917] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88862ecc7ca8 [283545.847920] R13: ffff88862ecc7d80 R14: ffff88862ecc72c0 R15: dffffc0000000000 [283545.847923] FS: 000073dc1824d800(0000) GS:ffff88862ec80000(0000) knlGS:0000000000000000 [283545.847926] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [283545.847928] CR2: 0000049400328000 CR3: 000000018a21c000 CR4: 0000000000752ef0 [283545.847965] PKRU: 55555554 [283545.847968] Call Trace: [283545.847971] <TASK> [283545.847668] rcu_gp_fqs_loop+0x1a3/0x970 [283545.848430] ? rcu_gp_init+0x8b7/0x1410 [283545.848436] ? __pfx_rcu_gp_fqs_loop+0x10/0x10 [283545.848440] ? finish_swait+0x12a/0x1f0 [283545.848445] ? prepare_to_swait_event+0xb8/0x350 [283545.848449] rcu_gp_kthread+0x27a/0x430 [283545.848452] ? __pfx_rcu_gp_kthread+0x10/0x10 [283545.848456] ? __kasan_check_read+0x11/0x20 [283545.847725] ? show_regs+0x71/0x90 [283545.848459] ? __kthread_parkme+0x8f/0x150 [283545.850678] ? schedule+0x83/0x350 [283545.850687] kthread+0x2b5/0x390 [283545.850691] ? __pfx_rcu_gp_kthread+0x10/0x10 [283545.850695] ? __pfx_kthread+0x10/0x10 [283545.850699] ret_from_fork+0x43/0x90 [283545.850705] ? __pfx_kthread+0x10/0x10 [283545.847975] ? show_regs+0x71/0x90 [283545.850100] ? watchdog_timer_fn+0x305/0x3d0 [283545.851262] ? __hrtimer_run_queues+0x2f0/0x7b0 [283545.851399] ? __pfx_watchdog_timer_fn+0x10/0x10 [283545.851405] ? __pfx___hrtimer_run_queues+0x10/0x10 [283545.851409] ? hrtimer_interrupt+0x2bc/0x750 [283545.850709] ret_from_fork_asm+0x1a/0x30 [283545.853112] </TASK> [283545.853172] Sending NMI from CPU 2 to CPUs 0: [283545.850722] ? __warn+0xd3/0x2d0 [283545.854922] ? enqueue_dl_entity+0x167f/0x3300 [283545.851414] ? __sysvec_apic_timer_interrupt+0x8e/0x310 [283545.875438] ? sysvec_apic_timer_interrupt+0x91/0xb0 [283545.875446] </IRQ> [283545.875449] <TASK> [283545.875471] ? asm_sysvec_apic_timer_interrupt+0x1b/0x20 [283545.875483] ? _raw_spin_unlock_irqrestore+0x21/0x60 [283545.854928] ? report_bug+0x2ad/0x300 [283545.900589] ? handle_bug+0x6e/0xc0 [283545.900593] ? exc_invalid_op+0x19/0x50 [283545.900596] ? asm_exc_invalid_op+0x1b/0x20 [283545.900602] ? enqueue_dl_entity+0x167f/0x3300 [283545.900607] ? update_cfs_group+0x274/0x2f0 [283545.901798] dl_server_start+0xd3/0x8a0 [283545.901805] enqueue_task_fair+0xb41/0x1830 [283545.901810] ? __pfx_sched_mm_cid_migrate_to+0x10/0x10 [283545.901814] enqueue_task+0x7f/0x540 [283545.901819] activate_task+0x5f/0xd0 [283545.901822] sched_balance_rq+0x13ba/0x3200 [283545.901825] ? sched_clock_cpu+0x6a/0x520 [283545.901830] ? sched_clock_noinstr+0x9/0x10 [283545.901836] ? __pfx_sched_balance_rq+0x10/0x10 [283545.901841] sched_balance_newidle+0x615/0x1040 [283545.901845] ? __pfx_sched_balance_newidle+0x10/0x10 [283545.901848] ? dequeue_entities+0x8ce/0x1330 [283545.901852] ? sched_clock_cpu+0x6a/0x520 [283545.901856] pick_next_task_fair+0x35/0xdb0 [283545.901859] ? dequeue_task_fair+0x232/0x5a0 [283545.901863] __pick_next_task+0x101/0x6d0 [283545.901866] __schedule+0x53e/0x4ee0 [283545.901871] ? update_stack_state+0x2d9/0x610 [283545.901877] ? __pfx___schedule+0x10/0x10 [283545.901880] ? _raw_write_unlock_irqrestore+0x80/0x90 [283545.901883] ? enqueue_hrtimer+0x10b/0x290 [283545.901888] ? hrtimer_start_range_ns+0x2f8/0xb60 [283545.901892] schedule+0x83/0x350 [283545.901895] schedule_hrtimeout_range_clock+0x15c/0x490 [283545.901900] ? __pfx_schedule_hrtimeout_range_clock+0x10/0x10 [283545.901904] ? __pfx_hrtimer_wakeup+0x10/0x10 [283545.901908] schedule_hrtimeout_range+0x13/0x30 [283545.901912] poll_schedule_timeout.constprop.0+0x79/0x100 [283545.901916] do_sys_poll+0x6f6/0xc10 [283545.901921] ? __pfx_do_sys_poll+0x10/0x10 [283545.901925] ? is_bpf_text_address+0x24/0x40 [283545.901929] ? kernel_text_address+0xd7/0xe0 [283545.901933] ? __kernel_text_address+0x12/0x50 [283545.901936] ? unwind_get_return_address+0x65/0xb0 [283545.901940] ? __pfx_stack_trace_consume_entry+0x10/0x10 [283545.901945] ? arch_stack_walk+0x9e/0x100 [283545.901951] ? __pfx_pollwake+0x10/0x10 [283545.901954] ? __pfx_pollwake+0x10/0x10 [283545.901748] INFO: NMI handler (perf_event_nmi_handler) took too long to run: 2.846 msecs [283545.901956] ? lockref_get_not_dead+0xd8/0x1f0 [283545.904986] ? putname+0xf4/0x150 [283545.904991] ? kasan_save_stack+0x3c/0x60 [283545.904995] ? kasan_save_stack+0x28/0x60 [283545.904999] ? kasan_save_track+0x18/0x70 [283545.905002] ? kasan_save_free_info+0x3b/0x60 [283545.905006] ? __kasan_slab_free+0x54/0x80 [283545.905009] ? kmem_cache_free+0x165/0x590 [283545.905014] ? putname+0xf4/0x150 [283545.905017] ? user_path_at+0x46/0x70 [283545.905020] ? user_statfs+0x8f/0x130 [283545.905751] ? __do_sys_statfs+0x87/0x120 [283545.905757] ? __x64_sys_statfs+0x54/0x80 [283545.905760] ? x64_sys_call+0xa30/0x2670 [283545.905764] ? do_syscall_64+0x7c/0x170 [283545.905768] ? entry_SYSCALL_64_after_hwframe+0x76/0x7e [283545.905775] ? try_to_unlazy+0x1cc/0x4b0 [283545.905779] ? terminate_walk+0x173/0x540 [283545.905783] ? path_lookupat+0x172/0x670 [283545.905786] ? x64_sys_call+0xa30/0x2670 [283545.905790] ? filename_lookup+0x1a6/0x520 [283545.905793] ? __pfx_timespec64_add_safe+0x10/0x10 [283545.905797] ? sched_clock_noinstr+0x9/0x10 [283545.905802] ? ktime_get_ts64+0x81/0x270 [283545.905807] __x64_sys_poll+0x180/0x500 [283545.905811] ? __pfx___x64_sys_poll+0x10/0x10 [283545.905814] ? lockref_put_return+0xd0/0x150 [283545.905818] ? __pfx_mntput_no_expire+0x10/0x10 [283545.905823] x64_sys_call+0x140e/0x2670 [283545.905826] do_syscall_64+0x7c/0x170 [283545.905829] ? mntput+0x57/0x90 [283545.905832] ? path_put+0x50/0x80 [283545.905836] ? user_statfs+0xbe/0x130 [283545.905839] ? __pfx_user_statfs+0x10/0x10 [283545.905842] ? __pfx_cp_new_stat+0x10/0x10 [283545.907651] ? __kasan_check_read+0x11/0x20 [283545.907656] ? _copy_to_user+0x3b/0x80 [283545.909759] ? __do_sys_statfs+0x101/0x120 [283545.909764] ? __pfx___do_sys_statfs+0x10/0x10 [283545.909793] ? __kasan_check_read+0x11/0x20 [283545.909803] ? fpregs_assert_state_consistent+0x21/0xb0 [283545.909810] ? syscall_exit_to_user_mode+0x4e/0x270 [283545.909815] ? do_syscall_64+0x88/0x170 [283545.909818] ? syscall_exit_to_user_mode+0x4e/0x270 [283545.909821] ? __kasan_check_read+0x11/0x20 [283545.909825] ? fpregs_assert_state_consistent+0x21/0xb0 [283545.909829] ? syscall_exit_to_user_mode+0x4e/0x270 [283545.909832] ? do_syscall_64+0x88/0x170 [283545.909834] ? clear_bhb_loop+0x15/0x70 [283545.909838] ? clear_bhb_loop+0x15/0x70 [283545.909842] ? clear_bhb_loop+0x15/0x70 [283545.909845] entry_SYSCALL_64_after_hwframe+0x76/0x7e [283545.909849] RIP: 0033:0x73dc18118bcf [283545.909855] Code: 54 24 1c 48 89 74 24 10 48 89 7c 24 08 e8 39 7e f7 ff 8b 54 24 1c 48 8b 74 24 10 41 89 c0 48 8b 7c 24 08 b8 07 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 89 44 24 08 e8 7d 7e f7 ff 8b 44 [283545.909859] RSP: 002b:00007fffd38bae60 EFLAGS: 00000293 ORIG_RAX: 0000000000000007 [283545.909865] RAX: ffffffffffffffda RBX: 000073dc1844e7a0 RCX: 000073dc18118bcf [283545.875487] ata_scsi_queuecmd+0x180/0x200 [283545.909868] RDX: 000000000000e9c5 RSI: 0000000000000002 RDI: 00005b604981cec0 [283545.909872] RBP: 00005b604981cec0 R08: 0000000000000000 R09: 0000000000000000 [283545.909875] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 [283545.909874] ? blk_mq_start_request+0xc1/0x770 [283545.909878] R13: 00007fffd38baea4 R14: 000000000000e9c5 R15: 00005b60497f9970 [283545.909883] </TASK> [283545.909886] ---[ end trace 0000000000000000 ]--- [283545.909883] scsi_queue_rq+0xb34/0x3320 [283545.922100] blk_mq_dispatch_rq_list+0x391/0x2570 [283545.922107] ? __kasan_check_read+0x11/0x20 [283545.922113] ? __pfx_blk_mq_dispatch_rq_list+0x10/0x10 [283545.922118] ? _raw_write_lock_nested+0x41/0xe0 [283545.922123] __blk_mq_sched_dispatch_requests+0x1dd/0x1620 [283545.922127] ? bio_kmalloc+0x23/0x40 [283545.923317] ? sr_check_events+0x1bc/0xa50 [283545.924738] ? cdrom_check_events+0x60/0x120 [283545.925485] ? __pfx___blk_mq_sched_dispatch_requests+0x10/0x10 [283545.925491] ? _raw_spin_lock+0x82/0xf0 [283545.925495] ? __pfx__raw_spin_lock+0x10/0x10 [283545.925498] ? policy_nodemask+0x239/0x360 [283545.925504] blk_mq_sched_dispatch_requests+0xb9/0x100 [283545.925510] blk_mq_run_hw_queue+0x32f/0x560 [283545.925514] blk_execute_rq+0x1a6/0x3d0 [283545.925518] ? __pfx_bio_add_pc_page+0x10/0x10 [283545.925521] ? __pfx_blk_execute_rq+0x10/0x10 [283545.925526] scsi_execute_cmd+0x39d/0xcc0 [283545.925530] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [283545.925533] ? __pfx_scsi_execute_cmd+0x10/0x10 [283545.925536] ? _raw_spin_lock+0x82/0xf0 [283545.925539] ? __kasan_check_write+0x14/0x30 [283545.925542] ? enqueue_timer+0xec/0x5b0 [283545.925548] sr_check_events+0x1bc/0xa50 [283545.925552] ? __pfx_sr_check_events+0x10/0x10 [283545.925554] ? __kasan_check_write+0x14/0x30 [283545.925558] ? _raw_spin_lock_irqsave+0x96/0x110 [283545.925561] ? rt_mutex_post_schedule+0x118/0x160 [283545.925580] ? add_timer_global+0x90/0xd0 [283545.925584] cdrom_check_events+0x60/0x120 [283545.925587] sr_block_check_events+0xab/0xe0 [283545.925590] disk_check_events+0xbb/0x3f0 [283545.925594] ? wake_up_process+0x15/0x30 [283545.925597] ? kick_pool+0x26c/0x680 [283545.926093] disk_events_workfn+0x19/0x30 [283545.926100] process_one_work+0x5f7/0x1060 [283545.926104] ? __kasan_check_write+0x14/0x30 [283545.926109] worker_thread+0x779/0x1200 [283545.926112] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [283545.926117] kthread+0x2b5/0x390 [283545.926121] ? __pfx_worker_thread+0x10/0x10 [283545.926124] ? __pfx_kthread+0x10/0x10 [283545.926128] ret_from_fork+0x43/0x90 [283545.926132] ? __pfx_kthread+0x10/0x10 [283545.926136] ret_from_fork_asm+0x1a/0x30 [283545.926141] </TASK>
