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 process_srcu run #2: crashed: BUG: soft lockup in do_idle run #3: crashed: BUG: soft lockup in khugepaged run #4: crashed: BUG: soft lockup in do_idle run #5: crashed: BUG: soft lockup in wb_workfn 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 rtnl_newlink run #9: crashed: BUG: soft lockup in do_idle run #10: crashed: BUG: soft lockup in wb_workfn 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 do_idle run #15: crashed: BUG: soft lockup in batadv_nc_worker run #16: crashed: BUG: soft lockup in do_idle run #17: crashed: BUG: soft lockup in batadv_iv_send_outstanding_bat_ogm_packet run #18: crashed: BUG: soft lockup in do_idle run #19: crashed: BUG: soft lockup in do_idle testing current HEAD fe07bfda2fb9cdef8a4d4008a409bb02f35f1bd8 testing commit fe07bfda2fb9cdef8a4d4008a409bb02f35f1bd8 with gcc (GCC) 10.2.1 20210217 kernel signature: 7070a100273933a756d4689bc89833ac92cc13879e4bd6be02d2703515f4e84f run #0: crashed: BUG: soft lockup in do_idle run #1: crashed: BUG: soft lockup in newlstat run #2: crashed: BUG: soft lockup in rtnl_newlink run #3: crashed: BUG: soft lockup in ext4_end_io_rsv_work run #4: crashed: BUG: soft lockup in wb_workfn run #5: crashed: BUG: soft lockup in addrconf_dad_work run #6: crashed: BUG: workqueue lockup run #7: crashed: BUG: workqueue lockup run #8: crashed: BUG: soft lockup in do_idle run #9: crashed: BUG: soft lockup in rtnl_newlink revisions tested: 2, total time: 22m20.553159785s (build: 12m55.646808397s, test: 8m38.18964603s) the crash still happens on HEAD commit msg: Linux 5.12-rc1 crash: BUG: soft lockup in rtnl_newlink watchdog: BUG: soft lockup - CPU#0 stuck for 40s! [syz-executor.1:6108] Modules linked in: irq event stamp: 149466 hardirqs last enabled at (149465): [] console_unlock+0x7fc/0xa00 kernel/printk/printk.c:2584 hardirqs last disabled at (149466): [] sysvec_apic_timer_interrupt+0xb/0xc0 arch/x86/kernel/apic/apic.c:1100 softirqs last enabled at (149448): [] invoke_softirq kernel/softirq.c:221 [inline] softirqs last enabled at (149448): [] __irq_exit_rcu kernel/softirq.c:422 [inline] softirqs last enabled at (149448): [] irq_exit_rcu+0x237/0x280 kernel/softirq.c:434 softirqs last disabled at (149399): [] invoke_softirq kernel/softirq.c:221 [inline] softirqs last disabled at (149399): [] __irq_exit_rcu kernel/softirq.c:422 [inline] softirqs last disabled at (149399): [] irq_exit_rcu+0x237/0x280 kernel/softirq.c:434 CPU: 0 PID: 6108 Comm: syz-executor.1 Not tainted 5.12.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:659 [inline] RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:145 [inline] RIP: 0010:console_unlock+0x826/0xa00 kernel/printk/printk.c:2584 Code: 48 c7 c0 00 f9 36 89 48 c1 e8 03 80 3c 18 00 0f 85 62 01 00 00 48 83 3d 47 21 e1 07 00 0f 84 8d 00 00 00 fb 66 0f 1f 44 00 00 d8 fd ff ff 48 89 c1 48 c7 c2 a0 e6 cb 87 be 40 00 00 00 48 c7 RSP: 0018:ffffc90000ddec80 EFLAGS: 00000282 RAX: 1ffffffff126df20 RBX: dffffc0000000000 RCX: 1ffffffff17f4c62 RDX: 0000000000000000 RSI: ffffffff87cb2840 RDI: ffffffff88128040 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffffff8bfa5ba7 R10: fffffbfff17f4b74 R11: 615f6e616d746162 R12: ffffffff89ce2708 R13: 0000000000000000 R14: ffffffff89ce26d0 R15: 0000000000000200 FS: 000000000222c400(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557bd50227d8 CR3: 000000010f9e3003 CR4: 00000000001706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vprintk_emit+0x1d1/0x4c0 kernel/printk/printk.c:2098 printk+0xad/0xde kernel/printk/printk.c:2146 batadv_check_known_mac_addr.cold+0x1f/0x28 net/batman-adv/hard-interface.c:517 batadv_hard_if_event+0x3d5/0x1150 net/batman-adv/hard-interface.c:1026 notifier_call_chain+0x94/0x170 kernel/notifier.c:83 call_netdevice_notifiers_extack net/core/dev.c:2075 [inline] call_netdevice_notifiers net/core/dev.c:2089 [inline] dev_set_mac_address+0x261/0x360 net/core/dev.c:8918 dev_set_mac_address_user+0x28/0x40 net/core/dev.c:8932 do_setlink+0x1271/0x2f10 net/core/rtnetlink.c:2663 __rtnl_newlink+0xab2/0x1350 net/core/rtnetlink.c:3376 rtnl_newlink+0x5a/0x90 net/core/rtnetlink.c:3491 rtnetlink_rcv_msg+0x32f/0x860 net/core/rtnetlink.c:5553 netlink_rcv_skb+0x118/0x370 net/netlink/af_netlink.c:2502 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x42e/0x700 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x70e/0xbe0 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg+0xab/0xe0 net/socket.c:674 __sys_sendto+0x1a4/0x270 net/socket.c:1977 __do_sys_sendto net/socket.c:1989 [inline] __se_sys_sendto net/socket.c:1985 [inline] __x64_sys_sendto+0xd8/0x1b0 net/socket.c:1985 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x416ff6 Code: 48 c7 c0 ff ff ff ff eb b7 66 2e 0f 1f 84 00 00 00 00 00 90 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 11 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 72 c3 90 55 48 83 ec 30 44 89 4c 24 2c 4c 89 RSP: 002b:00007ffd56b28b88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000a93700 RCX: 0000000000416ff6 RDX: 000000000000002c RSI: 0000000000a93750 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffd56b28b94 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000a93750