bisecting fixing commit since 4fa640dc52302b5e62b01b05c755b055549633ae building syzkaller on d88894e6773ab63ac8b3f4b2edbae88290aaf0d6 testing commit 4fa640dc52302b5e62b01b05c755b055549633ae with gcc (GCC) 8.4.1 20210217 kernel signature: 01ec0811025845132e25eee53b8aad732d2001a20ac9fec49e0d1dea11407386 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 do_idle 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 run #10: crashed: BUG: soft lockup in do_idle run #11: crashed: BUG: soft lockup in newlstat run #12: crashed: BUG: workqueue lockup run #13: crashed: BUG: soft lockup in linkwatch_event run #14: crashed: BUG: soft lockup in mutex_spin_on_owner run #15: crashed: BUG: soft lockup in do_idle run #16: crashed: BUG: soft lockup in do_idle run #17: crashed: BUG: workqueue lockup run #18: crashed: BUG: workqueue lockup run #19: crashed: INFO: rcu detected stall in do_idle testing current HEAD 1678e493d530e7977cce34e59a86bb86f3c5631e testing commit 1678e493d530e7977cce34e59a86bb86f3c5631e with gcc (GCC) 10.2.1 20210217 kernel signature: ebc7bbdcfd23a6ff4a7a5aa17fc4d6c89c623dbef882a06164021917070f0849 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 do_idle run #3: crashed: BUG: soft lockup in wb_workfn 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 linkwatch_event run #7: crashed: BUG: soft lockup in ext4_end_io_rsv_work run #8: crashed: BUG: soft lockup in do_idle run #9: crashed: BUG: soft lockup in iterate_cleanup_work revisions tested: 2, total time: 24m3.433850052s (build: 11m50.993763223s, test: 11m26.219423355s) the crash still happens on HEAD commit msg: Merge tag 'lto-v5.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux crash: BUG: soft lockup in iterate_cleanup_work watchdog: BUG: soft lockup - CPU#0 stuck for 42s! [kworker/0:6:7327] Modules linked in: irq event stamp: 113358 hardirqs last enabled at (113357): [] __local_bh_enable_ip+0x11f/0x220 kernel/softirq.c:203 hardirqs last disabled at (113358): [] sysvec_apic_timer_interrupt+0xb/0xc0 arch/x86/kernel/apic/apic.c:1100 softirqs last enabled at (113356): [] get_next_corpse net/netfilter/nf_conntrack_core.c:2197 [inline] softirqs last enabled at (113356): [] nf_ct_iterate_cleanup+0x73/0x270 net/netfilter/nf_conntrack_core.c:2245 softirqs last disabled at (113354): [] get_next_corpse net/netfilter/nf_conntrack_core.c:2197 [inline] softirqs last disabled at (113354): [] nf_ct_iterate_cleanup+0xb5/0x270 net/netfilter/nf_conntrack_core.c:2245 CPU: 0 PID: 7327 Comm: kworker/0:6 Not tainted 5.12.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events iterate_cleanup_work RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline] RIP: 0010:__local_bh_enable_ip+0x14f/0x220 kernel/softirq.c:205 Code: 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 bd 00 00 00 48 83 3d 2a f6 f5 07 00 74 4f fb 66 0f 1f 44 00 00 <65> 8b 05 9a fe c0 7e 85 c0 74 78 5b 5d 41 5c c3 65 8b 05 46 06 c1 RSP: 0018:ffffc90004417bd0 EFLAGS: 00000282 RAX: 1ffffffff126dec0 RBX: 00000000fffffe01 RCX: 1ffffffff1801c02 RDX: dffffc0000000000 RSI: ffffffff87cb2740 RDI: ffffffff88129500 RBP: 0000000000000200 R08: 0000000000000001 R09: ffffffff8bfaacaf R10: fffffbfff17f5595 R11: 0000000000000000 R12: ffffffff85e8e0a3 R13: ffffc90004417c70 R14: 000000000000aae5 R15: ffff88810f260500 FS: 0000000000000000(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000055c000 CR3: 0000000102671004 CR4: 00000000001706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: local_bh_enable include/linux/bottom_half.h:32 [inline] get_next_corpse net/netfilter/nf_conntrack_core.c:2222 [inline] nf_ct_iterate_cleanup+0x90/0x270 net/netfilter/nf_conntrack_core.c:2245 nf_ct_iterate_cleanup_net net/netfilter/nf_conntrack_core.c:2330 [inline] nf_ct_iterate_cleanup_net+0xfe/0x150 net/netfilter/nf_conntrack_core.c:2315 iterate_cleanup_work+0x3f/0xf0 net/netfilter/nf_nat_masquerade.c:216 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2275 worker_thread+0x598/0xf80 kernel/workqueue.c:2421 kthread+0x36f/0x450 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294