bisecting fixing commit since d183c8e2647a7d45202c14a33631f6c09020f8ac building syzkaller on dd56146d2611f7de0fbb7d8db6c016d3dcdc6371 testing commit d183c8e2647a7d45202c14a33631f6c09020f8ac with gcc (GCC) 8.1.0 kernel signature: d7d7b629495c39f1b1ce1b649f7b787cb1d1e26b630dbfc308b7fff168528f82 run #0: crashed: general protection fault in prepare_to_wait run #1: crashed: general protection fault in prepare_to_wait run #2: crashed: general protection fault in prepare_to_wait run #3: crashed: general protection fault in prepare_to_wait run #4: crashed: general protection fault in prepare_to_wait run #5: crashed: general protection fault in prepare_to_wait run #6: crashed: general protection fault in prepare_to_wait run #7: OK run #8: OK run #9: OK testing current HEAD 6dd0e32665e591e9debe3edaf73c2f8135bf047e testing commit 6dd0e32665e591e9debe3edaf73c2f8135bf047e with gcc (GCC) 8.1.0 kernel signature: 18f5cf13ed8dbd5d2d7d3bee7f279d66257b02e5f2734ff661dc4e9ba103b626 run #0: crashed: general protection fault in prepare_to_wait run #1: crashed: general protection fault in prepare_to_wait run #2: crashed: general protection fault in prepare_to_wait run #3: crashed: general protection fault in prepare_to_wait run #4: crashed: general protection fault in prepare_to_wait run #5: crashed: general protection fault in prepare_to_wait run #6: crashed: general protection fault in prepare_to_wait run #7: crashed: general protection fault in prepare_to_wait run #8: OK run #9: OK revisions tested: 2, total time: 40m30.35935826s (build: 18m30.015550991s, test: 20m42.525964264s) the crash still happens on HEAD commit msg: Linux 4.19.115 crash: general protection fault in prepare_to_wait batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! IPv6: ADDRCONF(NETDEV_UP): batadv_slave_0: link is not ready kasan: CONFIG_KASAN_INLINE enabled batman_adv: batadv0: Interface activated: batadv_slave_0 kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 7793 Comm: syz-executor.4 Not tainted 4.19.115-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x1e0/0x4980 kernel/locking/lockdep.c:3290 Code: 28 00 00 00 0f 85 2a 30 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f 85 28 32 00 00 49 81 7d 00 60 95 5c 89 0f 84 4a ff RSP: 0018:ffff88808b8a7900 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffffffff88520740 RBP: ffff88808b8a7af0 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000018 R14: ffff8880871c8700 R15: 0000000000000000 FS: 00007f93d5dac700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6861b6edb8 CR3: 000000008c690000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x173/0x3d0 kernel/locking/lockdep.c:3903 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 prepare_to_wait+0x90/0x310 kernel/sched/wait.c:230 nr_accept+0x1b0/0x690 net/netrom/af_netrom.c:796 __sys_accept4+0x32b/0x6b0 net/socket.c:1589 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! __do_sys_accept net/socket.c:1630 [inline] __se_sys_accept net/socket.c:1627 [inline] __x64_sys_accept+0x70/0xb0 net/socket.c:1627 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b349 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f93d5dabc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002b batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 RAX: ffffffffffffffda RBX: 00007f93d5dac6d4 RCX: 000000000045b349 RDX: 0000000020000100 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000000 R14: 00000000004c1558 R15: 000000000075c07c Modules linked in: ---[ end trace 66c6fa24ffe15f20 ]--- RIP: 0010:__lock_acquire+0x1e0/0x4980 kernel/locking/lockdep.c:3290 Code: 28 00 00 00 0f 85 2a 30 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f 85 28 32 00 00 49 81 7d 00 60 95 5c 89 0f 84 4a ff RSP: 0018:ffff88808b8a7900 EFLAGS: 00010006 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffffffff88520740 RBP: ffff88808b8a7af0 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000018 R14: ffff8880871c8700 R15: 0000000000000000 FS: 00007f93d5dac700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6861b6edb8 CR3: 000000008c690000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400