Hello, syzbot found the following issue on: HEAD commit: 382d4cd18475 lib/clz_ctz.c: Fix __clzdi2() and __ctzdi2() .. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14b7dfcfa80000 kernel config: https://syzkaller.appspot.com/x/.config?x=1e4a882f77ed77bd dashboard link: https://syzkaller.appspot.com/bug?extid=1425ba65f01a5682a1a2 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14bd9bcfa80000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=148070dba80000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/8f77bf610e28/disk-382d4cd1.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/63cde1098a7f/vmlinux-382d4cd1.xz kernel image: https://storage.googleapis.com/syzbot-assets/aa910d4c94be/bzImage-382d4cd1.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+1425ba65f01a5682a1a2@xxxxxxxxxxxxxxxxxxxxxxxxx rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=6dac/0/0x3 softirq=8535/8539 fqs=0 rcu: (t=10500 jiffies g=5401 q=100 ncpus=2) rcu: rcu_preempt kthread starved for 10500 jiffies! g5401 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:29008 pid:16 ppid:2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5381 [inline] __schedule+0xee1/0x59f0 kernel/sched/core.c:6710 schedule+0xe7/0x1b0 kernel/sched/core.c:6786 schedule_timeout+0x157/0x2c0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x1ec/0xa50 kernel/rcu/tree.c:1609 rcu_gp_kthread+0x249/0x380 kernel/rcu/tree.c:1808 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 </TASK> rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.5.0-rc7-syzkaller-00164-g382d4cd18475 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Workqueue: events request_firmware_work_func RIP: 0010:write_comp_data+0x7/0x90 kernel/kcov.c:230 Code: 81 e2 00 01 ff 00 75 10 65 48 8b 04 25 80 b9 03 00 48 8b 80 f8 15 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 65 8b 05 c1 b6 7d 7e <49> 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 RSP: 0018:ffffc90000007bb8 EFLAGS: 00000246 RAX: 0000000000000102 RBX: ffffc9000e151ea0 RCX: ffffffff88587d2c RDX: 0000000000000000 RSI: 0019999999999998 RDI: 0000000000000007 RBP: ffff88807d071b00 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00000015798ee228 R13: 0000000000000000 R14: 0000000225c17d04 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555640eca8 CR3: 0000000027cca000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <IRQ> pie_calculate_probability+0x1fc/0x850 net/sched/sch_pie.c:340 fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x764/0xb10 kernel/time/timer.c:2022 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035 __do_softirq+0x218/0x965 kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1109 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:console_flush_all+0x9b6/0xf50 kernel/printk/printk.c:2939 Code: 90 1b 23 00 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 8e 66 1c 00 48 85 db 0f 85 94 03 00 00 e8 f0 6a 1c 00 fb 48 8b 44 24 08 <48> 8b 14 24 0f b6 00 83 e2 07 38 d0 7f 08 84 c0 0f 85 9d 04 00 00 RSP: 0018:ffffc900000c7920 EFLAGS: 00000293 RAX: fffff52000018f4f RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88801664bb80 RSI: ffffffff81699db0 RDI: 0000000000000007 RBP: ffffffff8d4cb1a0 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 205d375420202020 R12: 0000000000000001 R13: ffffffff8d4cb1f8 R14: dffffc0000000000 R15: 0000000000000001 console_unlock+0xc6/0x1f0 kernel/printk/printk.c:3007 vprintk_emit+0x1c5/0x640 kernel/printk/printk.c:2307 vprintk+0x89/0xa0 kernel/printk/printk_safe.c:50 _printk+0xc8/0x100 kernel/printk/printk.c:2328 regdb_fw_cb+0x155/0x270 net/wireless/reg.c:1008 request_firmware_work_func+0x13a/0x240 drivers/base/firmware_loader/main.c:1162 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 </TASK> INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.097 msecs CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.5.0-rc7-syzkaller-00164-g382d4cd18475 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:write_comp_data+0x32/0x90 kernel/kcov.c:236 Code: 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 80 b9 03 00 a9 00 01 ff 00 74 0e 85 f6 74 59 8b 82 04 16 00 00 <85> c0 74 4f 8b 82 e0 15 00 00 83 f8 03 75 44 48 8b 82 e8 15 00 00 RSP: 0018:ffffc900001e0bb8 EFLAGS: 00000206 RAX: 0000000000000000 RBX: 0000000000abcc77 RCX: ffffffff88587ddd RDX: ffff888017261dc0 RSI: 0000000000000100 RDI: 0000000000000005 RBP: 00000010c6f7a0b5 R08: 0000000000000005 R09: 00000000000f4240 R10: 00000000000f4240 R11: 0000000000000000 R12: 00000000000f4240 R13: 0000000000000002 R14: 0000000000112e0b R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000080 CR3: 0000000020b50000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> pie_calculate_probability+0x2ad/0x850 net/sched/sch_pie.c:345 fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x764/0xb10 kernel/time/timer.c:2022 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035 __do_softirq+0x218/0x965 kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1109 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:72 [inline] RIP: 0010:acpi_safe_halt+0x1b/0x20 drivers/acpi/processor_idle.c:113 Code: ed c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 65 48 8b 04 25 80 b9 03 00 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 97 a6 a0 00 fb f4 <fa> c3 0f 1f 00 0f b6 47 08 3c 01 74 0b 3c 02 74 05 8b 7f 04 eb 9f RSP: 0018:ffffc90000177d60 EFLAGS: 00000246 RAX: 0000000000004000 RBX: 0000000000000001 RCX: ffffffff8a328aae RDX: 0000000000000001 RSI: ffff888145e5c000 RDI: ffff888145e5c064 RBP: ffff888145e5c064 R08: 0000000000000001 R09: ffffed1017326d9d R10: ffff8880b9936ceb R11: 0000000000000000 R12: ffff888013727000 R13: ffffffff8d4509c0 R14: 0000000000000001 R15: 0000000000000000 acpi_idle_enter+0xc5/0x160 drivers/acpi/processor_idle.c:707 cpuidle_enter_state+0x82/0x500 drivers/cpuidle/cpuidle.c:267 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:388 cpuidle_idle_call kernel/sched/idle.c:215 [inline] do_idle+0x315/0x3f0 kernel/sched/idle.c:282 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:379 start_secondary+0x200/0x290 arch/x86/kernel/smpboot.c:326 secondary_startup_64_no_verify+0x167/0x16b </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the bug is already fixed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite bug's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the bug is a duplicate of another bug, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
