bisecting fixing commit since 4fa640dc52302b5e62b01b05c755b055549633ae building syzkaller on d88894e6773ab63ac8b3f4b2edbae88290aaf0d6 testing commit 4fa640dc52302b5e62b01b05c755b055549633ae compiler: gcc (GCC) 8.4.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: 01ec0811025845132e25eee53b8aad732d2001a20ac9fec49e0d1dea11407386 run #0: crashed: BUG: soft lockup in do_idle run #1: crashed: BUG: workqueue lockup 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 sys_fchmod run #6: crashed: BUG: soft lockup in do_idle run #7: crashed: BUG: workqueue lockup run #8: crashed: BUG: soft lockup in do_idle run #9: crashed: BUG: soft lockup in do_idle run #10: crashed: BUG: workqueue lockup run #11: crashed: BUG: soft lockup in do_idle run #12: crashed: BUG: soft lockup in do_idle run #13: crashed: BUG: soft lockup in do_idle run #14: crashed: BUG: soft lockup in do_idle run #15: crashed: BUG: soft lockup in do_idle run #16: crashed: BUG: soft lockup in do_idle run #17: crashed: BUG: soft lockup in rtnl_newlink run #18: crashed: BUG: soft lockup in do_idle run #19: crashed: BUG: soft lockup in do_idle testing current HEAD 4a3bb4200a5958d76cc26ebe4db4257efa56812b testing commit 4a3bb4200a5958d76cc26ebe4db4257efa56812b compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: 00d1380ef7a5ef54051f319fd1a451e63aca247d7b9212fff05c54e0d0701233 run #0: crashed: BUG: soft lockup in do_idle run #1: crashed: BUG: soft lockup in ext4_end_io_rsv_work run #2: crashed: BUG: soft lockup in do_idle run #3: crashed: BUG: soft lockup in mutex_spin_on_owner run #4: crashed: BUG: soft lockup in smp_call_function run #5: crashed: BUG: soft lockup in do_idle run #6: crashed: BUG: soft lockup in mutex_spin_on_owner run #7: crashed: BUG: soft lockup in rtnl_newlink run #8: crashed: BUG: soft lockup in newlstat run #9: crashed: BUG: soft lockup in rtnl_newlink revisions tested: 2, total time: 23m14.387698398s (build: 11m58.306624031s, test: 10m24.334487928s) the crash still happens on HEAD commit msg: Merge tag 'dma-mapping-5.15' of git://git.infradead.org/users/hch/dma-mapping crash: BUG: soft lockup in rtnl_newlink watchdog: BUG: soft lockup - CPU#0 stuck for 39s! [syz-executor.4:6107] Modules linked in: irq event stamp: 0 hardirqs last enabled at (0): [<0000000000000000>] 0x0 hardirqs last disabled at (0): [] copy_process+0x1a1e/0x6950 kernel/fork.c:2063 softirqs last enabled at (0): [] copy_process+0x1a5a/0x6950 kernel/fork.c:2067 softirqs last disabled at (0): [<0000000000000000>] 0x0 CPU: 0 PID: 6107 Comm: syz-executor.4 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:console_unlock+0x57d/0x920 kernel/printk/printk.c:2715 Code: 48 c7 c0 00 8d 57 89 48 c1 e8 03 80 3c 18 00 0f 85 9e 03 00 00 48 83 3d 80 4f 00 08 00 0f 84 b5 02 00 00 fb 66 0f 1f 44 00 00 <45> 85 e4 0f 85 d1 01 00 00 8b 54 24 30 85 d2 0f 84 d4 fb ff ff 31 RSP: 0018:ffffc90000a6ec58 EFLAGS: 00000286 RAX: 1ffffffff12af1a0 RBX: dffffc0000000000 RCX: 1ffffffff14d0521 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff81573d63 RBP: ffffc90000a6ecb0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 615f6e616d746162 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff89f12ae8 FS: 000000000195b400(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb7f3c37000 CR3: 0000000123fc7005 CR4: 00000000001706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vprintk_emit+0xeb/0x3c0 kernel/printk/printk.c:2244 _printk+0xad/0xde kernel/printk/printk.c:2265 batadv_check_known_mac_addr.cold+0x1f/0x28 net/batman-adv/hard-interface.c:513 batadv_hard_if_event+0x3d5/0x11c0 net/batman-adv/hard-interface.c:963 notifier_call_chain+0x94/0x170 kernel/notifier.c:83 call_netdevice_notifiers_extack net/core/dev.c:2008 [inline] call_netdevice_notifiers net/core/dev.c:2022 [inline] dev_set_mac_address+0x261/0x360 net/core/dev.c:9018 dev_set_mac_address_user+0x28/0x40 net/core/dev.c:9032 do_setlink+0x12f2/0x2d60 net/core/rtnetlink.c:2674 __rtnl_newlink+0xaf5/0x13e0 net/core/rtnetlink.c:3391 rtnl_newlink+0x5a/0x90 net/core/rtnetlink.c:3506 rtnetlink_rcv_msg+0x31d/0x8d0 net/core/rtnetlink.c:5572 netlink_rcv_skb+0x118/0x370 net/netlink/af_netlink.c:2504 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x42e/0x700 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x704/0xbf0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xab/0xe0 net/socket.c:724 __sys_sendto+0x1a4/0x270 net/socket.c:2036 __do_sys_sendto net/socket.c:2048 [inline] __se_sys_sendto net/socket.c:2044 [inline] __x64_sys_sendto+0xd8/0x1b0 net/socket.c:2044 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 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:00007ffdc8361b68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000a93700 RCX: 0000000000416ff6 RDX: 000000000000002c RSI: 0000000000a93750 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffdc8361b74 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000a93750 ---------------- Code disassembly (best guess): 0: 48 c7 c0 00 8d 57 89 mov $0xffffffff89578d00,%rax 7: 48 c1 e8 03 shr $0x3,%rax b: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) f: 0f 85 9e 03 00 00 jne 0x3b3 15: 48 83 3d 80 4f 00 08 cmpq $0x0,0x8004f80(%rip) # 0x8004f9d 1c: 00 1d: 0f 84 b5 02 00 00 je 0x2d8 23: fb sti 24: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) * 2a: 45 85 e4 test %r12d,%r12d <-- trapping instruction 2d: 0f 85 d1 01 00 00 jne 0x204 33: 8b 54 24 30 mov 0x30(%rsp),%edx 37: 85 d2 test %edx,%edx 39: 0f 84 d4 fb ff ff je 0xfffffc13 3f: 31 .byte 0x31