bisecting fixing commit since 23ee3e4e5bd27bdbc0f1785eef7209ce872794c7 building syzkaller on 1f7cc1ca26f786658b146bf760d9698390e9bbfb testing commit 23ee3e4e5bd27bdbc0f1785eef7209ce872794c7 with gcc (GCC) 8.1.0 kernel signature: 1934ac818755f3d7ba9017b201a5af8760b85f8d47428001847a78476b2c40c8 run #0: crashed: BUG: unable to handle kernel NULL pointer dereference in rose_send_frame run #1: crashed: BUG: unable to handle kernel NULL pointer dereference in rose_send_frame run #2: crashed: BUG: unable to handle kernel NULL pointer dereference in rose_send_frame run #3: crashed: BUG: unable to handle kernel NULL pointer dereference in rose_send_frame run #4: crashed: BUG: unable to handle kernel NULL pointer dereference in rose_send_frame run #5: crashed: BUG: unable to handle kernel NULL pointer dereference in rose_send_frame run #6: crashed: BUG: unable to handle kernel NULL pointer dereference in rose_send_frame run #7: crashed: BUG: unable to handle kernel NULL pointer dereference in rose_send_frame run #8: crashed: BUG: unable to handle kernel NULL pointer dereference in rose_send_frame run #9: boot failed: can't ssh into the instance testing current HEAD c4d6fe7311762f2e03b3c27ad38df7c40c80cc93 testing commit c4d6fe7311762f2e03b3c27ad38df7c40c80cc93 with gcc (GCC) 8.1.0 kernel signature: 86edc65ecdccbd80763489d3a049bdcc54edf7fcc625a4c47a03178837518cc1 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in rose_send_frame revisions tested: 2, total time: 25m35.831955842s (build: 11m19.947368302s, test: 13m35.884411547s) the crash still happens on HEAD commit msg: Merge tag 'xarray-5.9' of git://git.infradead.org/users/willy/xarray crash: BUG: unable to handle kernel NULL pointer dereference in rose_send_frame BUG: kernel NULL pointer dereference, address: 0000000000000360 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 10ce66067 P4D 10ce66067 PUD 104303067 PMD 0 Oops: 0000 [#1] PREEMPT SMP CPU: 1 PID: 6978 Comm: syz-executor.3 Not tainted 5.9.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rose_send_frame+0x2c/0xc0 net/rose/rose_link.c:101 Code: 49 89 fc 48 c7 c7 e0 86 a4 86 55 53 48 89 f3 48 c7 c6 80 5d 99 83 e8 b3 39 00 00 4c 8b 4b 20 48 c7 c2 e0 86 a4 86 85 c0 75 07 <49> 8b 91 60 03 00 00 48 8b 6b 18 48 8d 4b 08 be 04 01 00 00 4c 89 RSP: 0018:ffffc90000d08d68 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff888134e2d400 RCX: 0000000000000000 RDX: ffffffff86a486e0 RSI: ffffffff83995d80 RDI: ffffffff86a486e0 RBP: 0000000000000032 R08: 00000000000000c0 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000009 R12: ffff88810cc17600 R13: 0000000000000078 R14: 0000000000000005 R15: ffffffff82bc8010 FS: 0000000000f31940(0000) GS:ffff88812c100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000360 CR3: 00000001078aa000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rose_transmit_clear_request+0x79/0xa0 net/rose/rose_link.c:255 rose_rx_call_request+0x172/0x630 net/rose/af_rose.c:998 rose_loopback_timer+0x81/0x150 net/rose/rose_loopback.c:100 call_timer_fn+0xa5/0x300 kernel/time/timer.c:1415 expire_timers kernel/time/timer.c:1460 [inline] __run_timers kernel/time/timer.c:1757 [inline] run_timer_softirq+0x20d/0x570 kernel/time/timer.c:1770 __do_softirq+0xe9/0x52f kernel/softirq.c:298 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x7c/0xa0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0xea/0x110 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x57/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:653 [inline] RIP: 0010:console_unlock+0x4d7/0x620 kernel/printk/printk.c:2507 Code: 40 5a 2f 84 e8 5a 09 ff ff e8 75 1c 00 00 4d 85 e4 0f 85 ba 00 00 00 48 83 3d dc de 08 03 00 0f 84 27 01 00 00 48 89 df 57 9d <0f> 1f 44 00 00 8b 44 24 0c 85 c0 0f 84 c4 fb ff ff 31 d2 be ce 09 RSP: 0018:ffffc90000e6f4b0 EFLAGS: 00000286 RAX: 000000000001d775 RBX: 0000000000000286 RCX: 0000000000000006 RDX: 0000000000000000 RSI: ffffffff83f27983 RDI: 0000000000000286 RBP: ffffffff84743ec8 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000001 R11: 615f6e616d746162 R12: 0000000000000200 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 vprintk_emit+0x156/0x380 kernel/printk/printk.c:2028 printk+0x53/0x6a kernel/printk/printk.c:2076 batadv_check_known_mac_addr.cold.25+0x8/0x19 net/batman-adv/hard-interface.c:516 batadv_hard_if_event+0xff/0x7a0 net/batman-adv/hard-interface.c:1047 notifier_call_chain+0x2f/0x90 kernel/notifier.c:83 call_netdevice_notifiers_extack net/core/dev.c:2046 [inline] call_netdevice_notifiers net/core/dev.c:2060 [inline] dev_set_mac_address+0xd9/0x110 net/core/dev.c:8680 do_setlink+0x1e4/0x10b0 net/core/rtnetlink.c:2661 __rtnl_newlink+0x538/0x8a0 net/core/rtnetlink.c:3374 rtnl_newlink+0x3e/0x60 net/core/rtnetlink.c:3500 rtnetlink_rcv_msg+0x173/0x480 net/core/rtnetlink.c:5563 netlink_rcv_skb+0x49/0xf0 net/netlink/af_netlink.c:2494 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x19a/0x270 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x248/0x480 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0x2b/0x40 net/socket.c:671 __sys_sendto+0xec/0x160 net/socket.c:1992 __do_sys_sendto net/socket.c:2004 [inline] __se_sys_sendto net/socket.c:2000 [inline] __x64_sys_sendto+0x1f/0x30 net/socket.c:2000 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x416043 Code: ff 0f 83 b0 19 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 4d 39 89 00 00 75 17 49 89 ca b8 2c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 81 19 00 00 c3 48 83 ec 08 e8 87 fa ff ff RSP: 002b:00007fff707a52a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000ca3700 RCX: 0000000000416043 RDX: 000000000000002c RSI: 0000000000ca3750 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007fff707a52b0 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000ca3750 R15: 0000000000000003 Modules linked in: CR2: 0000000000000360 ---[ end trace d9983fb9d71db5c8 ]--- RIP: 0010:rose_send_frame+0x2c/0xc0 net/rose/rose_link.c:101 Code: 49 89 fc 48 c7 c7 e0 86 a4 86 55 53 48 89 f3 48 c7 c6 80 5d 99 83 e8 b3 39 00 00 4c 8b 4b 20 48 c7 c2 e0 86 a4 86 85 c0 75 07 <49> 8b 91 60 03 00 00 48 8b 6b 18 48 8d 4b 08 be 04 01 00 00 4c 89 RSP: 0018:ffffc90000d08d68 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff888134e2d400 RCX: 0000000000000000 RDX: ffffffff86a486e0 RSI: ffffffff83995d80 RDI: ffffffff86a486e0 RBP: 0000000000000032 R08: 00000000000000c0 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000009 R12: ffff88810cc17600 R13: 0000000000000078 R14: 0000000000000005 R15: ffffffff82bc8010 FS: 0000000000f31940(0000) GS:ffff88812c100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000360 CR3: 00000001078aa000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400