bisecting fixing commit since 0f091e43310f5c292b7094f9f115e651358e8053 building syzkaller on d5a3ae1f760e7cb2cd5a721d9645ae22eae114fe testing commit 0f091e43310f5c292b7094f9f115e651358e8053 with gcc (GCC) 8.4.1 20210217 kernel signature: a98e028563c794949bf01c456c8e9e0b870e794739718df27c2ed1c3472e683e run #0: crashed: BUG: soft lockup in linkwatch_event run #1: crashed: BUG: soft lockup in do_idle run #2: crashed: BUG: soft lockup in do_idle run #3: crashed: BUG: soft lockup in do_idle run #4: crashed: BUG: soft lockup in rtnl_newlink run #5: crashed: BUG: soft lockup in do_idle run #6: crashed: BUG: soft lockup in linkwatch_event run #7: crashed: BUG: soft lockup in sys_exit_group run #8: crashed: BUG: soft lockup in do_idle run #9: crashed: BUG: soft lockup in do_idle run #10: crashed: BUG: soft lockup in do_idle run #11: crashed: BUG: soft lockup in do_idle run #12: crashed: BUG: soft lockup in do_idle run #13: crashed: BUG: workqueue lockup run #14: crashed: BUG: soft lockup in filemap_map_pages run #15: crashed: BUG: soft lockup in wb_workfn run #16: crashed: BUG: soft lockup in wb_workfn run #17: crashed: BUG: soft lockup in do_idle run #18: crashed: BUG: soft lockup in do_idle run #19: crashed: INFO: rcu detected stall in do_idle testing current HEAD 040806343bb4ef6365166eae666ced8a91b95321 testing commit 040806343bb4ef6365166eae666ced8a91b95321 with gcc (GCC) 10.2.1 20210217 kernel signature: 7a9a2a5d8e93289faded14743c6af3b3afbb383c7525cd9deb719b3823aab401 run #0: crashed: BUG: soft lockup in do_idle run #1: crashed: BUG: soft lockup in do_idle run #2: crashed: BUG: soft lockup in rtnl_newlink run #3: crashed: BUG: soft lockup in do_idle run #4: crashed: BUG: soft lockup in do_idle run #5: crashed: BUG: soft lockup in do_idle run #6: crashed: BUG: soft lockup in do_idle run #7: crashed: BUG: soft lockup in do_idle run #8: crashed: BUG: soft lockup in do_idle run #9: crashed: BUG: soft lockup in do_idle revisions tested: 2, total time: 23m58.495591898s (build: 13m41.827313945s, test: 9m35.10419881s) the crash still happens on HEAD commit msg: selftests/net: so_txtime multi-host support crash: BUG: soft lockup in do_idle watchdog: BUG: soft lockup - CPU#0 stuck for 33s! [swapper/0:0] Modules linked in: irq event stamp: 194958 hardirqs last enabled at (194957): [] acpi_safe_halt drivers/acpi/processor_idle.c:110 [inline] hardirqs last enabled at (194957): [] acpi_idle_do_entry+0x157/0x290 drivers/acpi/processor_idle.c:516 hardirqs last disabled at (194958): [] sysvec_apic_timer_interrupt+0xb/0xc0 arch/x86/kernel/apic/apic.c:1100 softirqs last enabled at (194946): [] invoke_softirq kernel/softirq.c:221 [inline] softirqs last enabled at (194946): [] __irq_exit_rcu kernel/softirq.c:422 [inline] softirqs last enabled at (194946): [] irq_exit_rcu+0x237/0x280 kernel/softirq.c:434 softirqs last disabled at (194939): [] invoke_softirq kernel/softirq.c:221 [inline] softirqs last disabled at (194939): [] __irq_exit_rcu kernel/softirq.c:422 [inline] softirqs last disabled at (194939): [] irq_exit_rcu+0x237/0x280 kernel/softirq.c:434 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:52 Code: e8 97 7b 32 fa e9 e4 fe ff ff 48 89 df e8 8a 7b 32 fa eb 9c cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 64 65 56 00 fb f4 90 e9 07 00 00 00 0f 00 2d 54 65 56 00 f4 c3 cc cc 55 53 e8 f9 RSP: 0018:ffffffff89207d70 EFLAGS: 00000282 RAX: 1ffffffff126dec1 RBX: ffff888103d0a065 RCX: 1ffffffff1486841 RDX: dffffc0000000000 RSI: ffffffff87cb26c0 RDI: ffffffff88129cc0 RBP: ffffffff8929a4c0 R08: 0000000000000001 R09: 0000000000000001 R10: fffffbfff1253498 R11: 0000000000000001 R12: 0000000000000001 R13: ffffffff89a7af00 R14: ffff888103d0a064 R15: ffff88810899e004 FS: 0000000000000000(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c8533383d8 CR3: 00000001045bf002 CR4: 00000000001706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:150 [inline] acpi_safe_halt drivers/acpi/processor_idle.c:110 [inline] acpi_idle_do_entry+0x189/0x290 drivers/acpi/processor_idle.c:516 acpi_idle_enter+0x2d4/0x4a0 drivers/acpi/processor_idle.c:647 cpuidle_enter_state+0x145/0x990 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x45/0xa0 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x48e/0x730 kernel/sched/idle.c:300 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:397 start_kernel+0x34a/0x368 init/main.c:1064 secondary_startup_64_no_verify+0xb0/0xbb