bisecting fixing commit since 87335852c5d9ec629f80bb2257b9a9945962b719 building syzkaller on 2f1cec6277878744f2f5484a1833fb91903515f2 testing commit 87335852c5d9ec629f80bb2257b9a9945962b719 with gcc (GCC) 8.1.0 kernel signature: 41fb2f93fa602b6b3302677440605374974c6d73be93dbfb1bcbdd7a56267d70 all runs: crashed: general protection fault in ieee80211_subif_start_xmit testing current HEAD 3f2ecb86cb909da0b9157fd2952ad79924cbe5ae testing commit 3f2ecb86cb909da0b9157fd2952ad79924cbe5ae with gcc (GCC) 8.1.0 kernel signature: 774916fe4d22907af6c8a0df6ac5c3fa840cb05ed50aae453ee485c0e474ccc4 all runs: crashed: general protection fault in ieee80211_subif_start_xmit revisions tested: 2, total time: 25m33.40387575s (build: 16m58.572651042s, test: 7m48.57074657s) the crash still happens on HEAD commit msg: Linux 4.14.212 crash: general protection fault in ieee80211_subif_start_xmit wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50 ieee80211 phy15: mac80211_hwsim_configure_filter kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 0 PID: 16459 Comm: syz-executor.5 Not tainted 4.14.212-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8881e5974580 task.stack: ffff8881d8670000 RIP: 0010:ieee80211_multicast_to_unicast net/mac80211/tx.c:3680 [inline] RIP: 0010:ieee80211_subif_start_xmit+0x20a/0xf60 net/mac80211/tx.c:3764 RSP: 0018:ffff8881f64074e0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff8881d0988900 RDX: 000000000000003b RSI: ffff8881d0988900 RDI: 00000000000001d8 RBP: ffff8881f6407608 R08: 1ffff1103cb2e9c0 R09: ffffffff8aa997d8 R10: ffff8881f64075e0 R11: ffff8881e5974580 R12: 1ffff1103ec80ea8 R13: ffff8881df134ec2 R14: ffff8881d3acb8c0 R15: ffff8881d3acb998 FS: 00007f32e8921700(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f32dcc4c000 CR3: 00000001ee28d001 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __netdev_start_xmit include/linux/netdevice.h:4039 [inline] netdev_start_xmit include/linux/netdevice.h:4048 [inline] xmit_one net/core/dev.c:3005 [inline] dev_hard_start_xmit+0x15e/0x780 net/core/dev.c:3021 sch_direct_xmit+0x26f/0x520 net/sched/sch_generic.c:186 __dev_xmit_skb net/core/dev.c:3214 [inline] __dev_queue_xmit+0x18e6/0x25b0 net/core/dev.c:3489 dev_queue_xmit+0xb/0x10 net/core/dev.c:3554 neigh_hh_output include/net/neighbour.h:490 [inline] neigh_output include/net/neighbour.h:498 [inline] ip6_finish_output2+0xc2e/0x2070 net/ipv6/ip6_output.c:120 ip6_finish_output+0x56d/0xa50 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:239 [inline] ip6_output+0x1b3/0x610 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:470 [inline] NF_HOOK include/linux/netfilter.h:250 [inline] mld_sendpack+0x635/0xe10 net/ipv6/mcast.c:1660 mld_send_cr net/ipv6/mcast.c:1956 [inline] mld_ifc_timer_expire+0x361/0x720 net/ipv6/mcast.c:2455 call_timer_fn+0x142/0x570 kernel/time/timer.c:1280 expire_timers+0x299/0x440 kernel/time/timer.c:1319 __run_timers kernel/time/timer.c:1637 [inline] run_timer_softirq+0x1cd/0x540 kernel/time/timer.c:1650 __do_softirq+0x246/0x9b5 kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x15f/0x1a0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x145/0x5d0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x9a/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] RIP: 0010:console_trylock_spinning kernel/printk/printk.c:1685 [inline] RIP: 0010:vprintk_emit+0x42c/0x4e0 kernel/printk/printk.c:1922 RSP: 0018:ffff8881d8677088 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: 0000000000000282 RCX: 1ffff1103cb2e9cf RDX: 0000000000000000 RSI: ffff8881e5974e58 RDI: 0000000000000282 RBP: ffff8881d86770d8 R08: ffff8881e5974e78 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffffffff11e1098 R13: 1ffffffff11e109a R14: 0000000000000000 R15: 1ffffffff11e1099 dev_vprintk_emit+0x1ca/0x3b0 drivers/base/core.c:2989 dev_printk_emit+0x88/0xa0 drivers/base/core.c:3000 __dev_printk+0xd7/0x2e0 drivers/base/core.c:3012 dev_printk+0xab/0xd0 drivers/base/core.c:3029 mac80211_hwsim_configure_filter+0x79/0x120 drivers/net/wireless/mac80211_hwsim.c:1667 drv_configure_filter net/mac80211/driver-ops.h:205 [inline] ieee80211_configure_filter+0x429/0xe90 net/mac80211/main.c:76 ieee80211_do_stop+0xeac/0x1de0 net/mac80211/iface.c:1085 ieee80211_runtime_change_iftype net/mac80211/iface.c:1562 [inline] ieee80211_if_change_type+0x240/0x400 net/mac80211/iface.c:1596 ieee80211_change_iface+0x29/0x1e0 net/mac80211/cfg.c:156 rdev_change_virtual_intf net/wireless/rdev-ops.h:69 [inline] cfg80211_change_iface+0x200/0x1160 net/wireless/util.c:1048 nl80211_set_interface+0x443/0x840 net/wireless/nl80211.c:2929 genl_family_rcv_msg+0x57f/0xfe0 net/netlink/genetlink.c:600 genl_rcv_msg+0xa7/0x140 net/netlink/genetlink.c:625 netlink_rcv_skb+0x12f/0x3b0 net/netlink/af_netlink.c:2433 genl_rcv+0x23/0x40 net/netlink/genetlink.c:636 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x40b/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x657/0xc60 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:656 SYSC_sendto net/socket.c:1763 [inline] SyS_sendto+0x1e4/0x2c0 net/socket.c:1731 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x417937 RSP: 002b:00007f32e891fa90 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f32e891fbe0 RCX: 0000000000417937 RDX: 0000000000000024 RSI: 00007f32e891fc30 RDI: 0000000000000007 RBP: 0000000000000000 R08: 00007f32e891faa0 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f32e891fc30 R15: 0000000000000007 Code: 85 4c 0d 00 00 48 8b 85 30 ff ff ff 48 8b 98 70 14 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bb d8 01 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 06 0f 8e 34 0d 00 00 80 bb d8 01 00 00 00 RIP: ieee80211_multicast_to_unicast net/mac80211/tx.c:3680 [inline] RSP: ffff8881f64074e0 RIP: ieee80211_subif_start_xmit+0x20a/0xf60 net/mac80211/tx.c:3764 RSP: ffff8881f64074e0 ---[ end trace 346fe60d7cbee8b1 ]---