bisecting fixing commit since 811218eceeaa7618652e1b8d11caeff67ab42072 building syzkaller on 98682e5e2aefc9aad61354f4f3ac93be96002a2a testing commit 811218eceeaa7618652e1b8d11caeff67ab42072 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 81aaee3bd25e09fbb64dcb2cfe034b3757941a18bbc99d924d0f3fd3aef58e1a all runs: crashed: general protection fault in hsr_netdev_notify testing current HEAD 59456c9cc40c8f75b5a7efa0fe1f211d9c6fcaf1 testing commit 59456c9cc40c8f75b5a7efa0fe1f211d9c6fcaf1 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: ecb75913eac2cf0b74f3d773ab00e786a46b3ca04ff74f127acd69ceda2f4c24 all runs: crashed: general protection fault in hsr_netdev_notify revisions tested: 2, total time: 28m37.986592002s (build: 21m25.293312167s, test: 6m45.29161305s) the crash still happens on HEAD commit msg: Linux 4.19.204 crash: general protection fault in hsr_netdev_notify bond0 (unregistering): Releasing backup interface bond_slave_0 kasan: CONFIG_KASAN_INLINE enabled Bluetooth: hci0: command 0x040f tx timeout kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 46 Comm: kworker/u4:2 Not tainted 4.19.204-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:hsr_netdev_notify+0x2db/0xa40 net/hsr/hsr_main.c:64 Code: 42 80 3c 20 00 0f 85 83 05 00 00 48 8b 1b 4c 39 fb 75 c4 31 db 4c 8d 73 10 48 b8 00 00 00 00 00 fc ff df 4c 89 f6 48 c1 ee 03 <80> 3c 06 00 0f 85 e5 05 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b RSP: 0018:ffff8880b50f75b0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff8880970b3180 RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff8880a1e57f20 RBP: ffff8880b50f75e8 R08: 1ffff11016a1b9a8 R09: fffffbfff14f2418 R10: fffffbfff14f2418 R11: ffffffff8a7920c7 R12: dffffc0000000000 R13: ffff88809f1e1e80 R14: 0000000000000010 R15: ffff8880970b3190 FS: 0000000000000000(0000) GS:ffff8880ba200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f61f6867000 CR3: 00000000aafe5000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: notifier_call_chain+0x8a/0x160 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x11/0x20 kernel/notifier.c:401 call_netdevice_notifiers_info+0x28/0x60 net/core/dev.c:1744 call_netdevice_notifiers+0x67/0x90 net/core/dev.c:1762 __bond_release_one+0xead/0x1410 drivers/net/bonding/bond_main.c:1982 bond_slave_netdev_event drivers/net/bonding/bond_main.c:3154 [inline] bond_netdev_event+0x844/0x9b0 drivers/net/bonding/bond_main.c:3266 notifier_call_chain+0x8a/0x160 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x11/0x20 kernel/notifier.c:401 call_netdevice_notifiers_info+0x28/0x60 net/core/dev.c:1744 call_netdevice_notifiers net/core/dev.c:1762 [inline] rollback_registered_many+0x5ca/0xbe0 net/core/dev.c:8196 unregister_netdevice_many+0x3e/0x1f0 net/core/dev.c:9324 default_device_exit_batch+0x2e4/0x3d0 net/core/dev.c:9795 ops_exit_list.isra.0+0xd3/0x120 net/core/net_namespace.c:156 cleanup_net+0x368/0x850 net/core/net_namespace.c:553 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2153 worker_thread+0x85/0xb60 kernel/workqueue.c:2296 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Modules linked in: ---[ end trace bfd6f2080a0ed90a ]--- RIP: 0010:hsr_netdev_notify+0x2db/0xa40 net/hsr/hsr_main.c:64 Code: 42 80 3c 20 00 0f 85 83 05 00 00 48 8b 1b 4c 39 fb 75 c4 31 db 4c 8d 73 10 48 b8 00 00 00 00 00 fc ff df 4c 89 f6 48 c1 ee 03 <80> 3c 06 00 0f 85 e5 05 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b RSP: 0018:ffff8880b50f75b0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff8880970b3180 RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff8880a1e57f20 RBP: ffff8880b50f75e8 R08: 1ffff11016a1b9a8 R09: fffffbfff14f2418 R10: fffffbfff14f2418 R11: ffffffff8a7920c7 R12: dffffc0000000000 R13: ffff88809f1e1e80 R14: 0000000000000010 R15: ffff8880970b3190 FS: 0000000000000000(0000) GS:ffff8880ba200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f560b3a0ab4 CR3: 000000000986d000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) 5: 0f 85 83 05 00 00 jne 0x58e b: 48 8b 1b mov (%rbx),%rbx e: 4c 39 fb cmp %r15,%rbx 11: 75 c4 jne 0xffffffd7 13: 31 db xor %ebx,%ebx 15: 4c 8d 73 10 lea 0x10(%rbx),%r14 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 20: fc ff df 23: 4c 89 f6 mov %r14,%rsi 26: 48 c1 ee 03 shr $0x3,%rsi 2a: 80 3c 06 00 cmpb $0x0,(%rsi,%rax,1) <-- trapping instruction 2e: 0f 85 e5 05 00 00 jne 0x619 34: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 3b: fc ff df 3e: 4c rex.WR 3f: 8b .byte 0x8b