panic: runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x1 addr=0xa0 pc=0x7a08f1] goroutine 24 [running]: github.com/google/syzkaller/prog.chooseCall.func1(0x9a7720, 0xc00365cd00, 0xc00366b2c0) /syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:198 +0x51 github.com/google/syzkaller/prog.foreachArgImpl(0x9a7720, 0xc00365cd00, 0xc00365c988, 0xc0036603f0, 0x3f, 0x0, 0xc0003add60) /syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:125 +0xbe github.com/google/syzkaller/prog.foreachArgImpl(0x9a7760, 0xc00365bb60, 0xc00365c988, 0xc0036603f0, 0x3f, 0x0, 0xc0003add60) /syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:154 +0x40b github.com/google/syzkaller/prog.foreachArgImpl(0x9a76a0, 0xc003660420, 0xc00365c988, 0xc0036603f0, 0x0, 0x885e00, 0xc0003add60) /syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:136 +0x1c8 github.com/google/syzkaller/prog.foreachArgImpl(0x9a76e0, 0xc0036603f0, 0xc00365c988, 0x0, 0x0, 0x0, 0xc0003add60) /syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:151 +0x3a6 github.com/google/syzkaller/prog.ForeachArg(0xc00365c980, 0xc0003add60) /syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:120 +0x9e github.com/google/syzkaller/prog.chooseCall(0xc0035eee80, 0xc003664680, 0xc003661500, 0xc0003addc0) /syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:197 +0x10d github.com/google/syzkaller/prog.(*mutator).mutateArg(0xc0003adec0, 0xa) /syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:161 +0x67 github.com/google/syzkaller/prog.(*Prog).Mutate(0xc0035eee80, 0x9a1f20, 0xc002b988d0, 0x1e, 0xc002be6000, 0xc002d68000, 0x1e72, 0x2400) /syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:44 +0x2da main.(*Proc).loop(0xc002be6080) /syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/proc.go:99 +0x434 created by main.main /syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:259 +0x114c OpenBSD/amd64 (ci-openbsd-multicore-6.c.syzkaller.internal) (tty00) login: uvm_fault(0xfffffd807f000a10, 0x1dfc, 0, 1) -> e kernel: page fault trap, code=0 Stopped at in_delmulti+0x8d: movl 0xc(%r14),%r15d ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic kernel page fault uvm_fault(0xfffffd807f000a10, 0x1dfc, 0, 1) -> e in_delmulti(1df0) at in_delmulti+0x8d sys/netinet/in.c:914 end trace frame: 0xffff80002279f7b0, count: 0 ddb{0}> trace in_delmulti(1df0) at in_delmulti+0x8d sys/netinet/in.c:914 in_purgeaddr(ffff800000a8e100) at in_purgeaddr+0x156 sys/netinet/in.c:760 in_ifdetach(ffff800000a1d800) at in_ifdetach+0x74 sys/netinet/in.c:969 if_detach(ffff800000a1d800) at if_detach+0x140 sys/net/if.c:1150 tun_clone_destroy(ffff800000a1d800) at tun_clone_destroy+0x1f2 sys/net/if_tun.c:329 tun_dev_close(5d01,7) at tun_dev_close+0x160 sys/net/if_tun.c:480 spec_close(ffff80002279f990) at spec_close+0x311 sys/kern/spec_vnops.c:555 VOP_CLOSE(fffffd806edc1348,7,fffffd807f7be900,ffff800020a7d868) at VOP_CLOSE+0xc0 sys/kern/vfs_vops.c:175 vn_closefile(fffffd80673c7dc0,ffff800020a7d868) at vn_closefile+0xd7 vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(fffffd80673c7dc0,ffff800020a7d868) at vn_closefile+0xd7 sys/kern/vfs_vnops.c:610 fdrop(fffffd80673c7dc0,ffff800020a7d868) at fdrop+0xc2 sys/kern/kern_descrip.c:1264 closef(fffffd80673c7dc0,ffff800020a7d868) at closef+0x11c sys/kern/kern_descrip.c:1248 fdfree(ffff800020a7d868) at fdfree+0x101 sys/kern/kern_descrip.c:1180 exit1(ffff800020a7d868,0,d,1) at exit1+0x344 sys/kern/kern_exit.c:196 postsig(ffff800020a7d868,d) at postsig+0x4e5 sigexit sys/kern/kern_sig.c:1476 [inline] postsig(ffff800020a7d868,d) at postsig+0x4e5 sys/kern/kern_sig.c:1408 userret(ffff800020a7d868) at userret+0x199 sys/kern/kern_sig.c:1860 syscall(ffff80002279fe10) at syscall+0x55f mi_syscall_return sys/sys/syscall_mi.h:129 [inline] syscall(ffff80002279fe10) at syscall+0x55f sys/arch/amd64/amd64/trap.c:592 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe8ed0, count: -17 ddb{0}> show registers rdi 0x2 rsi 0 rbp 0xffff80002279f760 rbx 0 rdx 0xffff800020a7d868 rcx 0 rax 0 r8 0xffffffff81070463 rt_ifa_purge+0x153 r9 0x5 r10 0x2f r11 0xf4dac687ab954629 r12 0 r13 0x3 r14 0x1df0 __ALIGN_SIZE+0xdf0 r15 0x1 rip 0xffffffff814b1dfd in_delmulti+0x8d cs 0x8 rflags 0x10246 __ALIGN_SIZE+0xf246 rsp 0xffff80002279f700 ss 0x10 in_delmulti+0x8d: movl 0xc(%r14),%r15d ddb{0}> show proc PROC (syz-executor.1) pid=513986 stat=onproc flags process=a proc=2000 pri=32, usrpri=74, nice=20 forw=0xffffffffffffffff, list=0xffff800020a7dad8,0xffff800020ac2778 process=0xffff800020a91a50 user=0xffff80002279a000, vmspace=0xfffffd807f000a10 estcpu=36, cpticks=2, pctcpu=0.19 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 53850 243440 0 0 3 0x14200 bored sosplice 75593 413183 66063 0 3 0x10008a pause ksh 66063 506460 69158 0 3 0x92 select sshd 35736 8348 1 0 3 0x100083 ttyin getty 69158 195522 1 0 3 0x80 select sshd 72777 262930 43418 74 3 0x100092 bpf pflogd 43418 249370 1 0 3 0x80 netio pflogd 30771 376262 70399 73 3 0x100090 kqread syslogd 70399 437641 1 0 3 0x100082 netio syslogd 69303 467418 0 0 2 0x14200 zerothread 10834 26287 0 0 3 0x14200 aiodoned aiodoned 3848 239859 0 0 3 0x14200 syncer update 13710 241906 0 0 3 0x14200 cleaner cleaner 25666 49387 0 0 7 0x14200 reaper 35812 301347 0 0 3 0x14200 pgdaemon pagedaemon 32148 201238 0 0 3 0x14200 bored crynlk 2419 477987 0 0 3 0x14200 bored crypto 25728 264503 0 0 3 0x40014200 acpi0 acpi0 70218 106448 0 0 3 0x40014200 idle1 6716 350173 0 0 3 0x14200 bored softnet 80820 459912 0 0 2 0x14200 systqmp 43469 2239 0 0 3 0x14200 bored systq 93250 282986 0 0 3 0x40014200 bored softclock 73287 90802 0 0 3 0x40014200 idle0 3265 266964 0 0 3 0x14200 bored smr 1 138586 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9501 6349K 7048K 78643K 11185 0 pcb 13 8K 8K 78643K 131 0 rtable 111 4K 5K 78643K 333 0 ifaddr 70 14K 15K 78643K 140 0 counters 43 33K 34K 78643K 67 0 ioctlops 0 0K 4K 78643K 1482 0 iov 0 0K 16K 78643K 43 0 mount 1 1K 1K 78643K 1 0 vnodes 1214 76K 77K 78643K 1389 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 6 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 1K 78643K 58 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 3 8K 25K 78643K 405 0 sigio 0 0K 0K 78643K 1 0 proc 57 51K 95K 78643K 469 0 subproc 14 0K 2K 78643K 34 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 45 0 in_multi 55 2K 3K 78643K 97 0 ether_multi 1 0K 0K 78643K 12 0 mrt 0 0K 0K 78643K 7 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 49 228K 228K 78643K 49 0 exec 0 0K 1K 78643K 255 0 pfkey data 0 0K 0K 78643K 2 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 7 26K 26K 78643K 7 0 UVM amap 93 20K 38K 78643K 2152 0 UVM aobj 63 4K 4K 78643K 67 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 66 0 NDP 11 0K 0K 78643K 28 0 temp 118 3016K 3080K 78643K 4554 0 kqueue 2 2K 16K 78643K 40 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 13 0 6 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 51 0 51 2 1 1 1 0 8 1 rtentry 112 69 0 25 2 0 2 2 0 8 0 unpcb 120 363 0 353 1 0 1 1 0 8 0 syncache 264 8 0 8 2 2 0 1 0 8 0 tcpqe 32 393 0 393 1 1 0 1 0 8 0 tcpcb 544 570 0 567 4 2 2 2 0 8 1 inpcb 280 968 0 963 4 1 3 3 0 8 1 rttmr 72 2 0 2 1 1 0 1 0 8 0 nd6 48 5 0 2 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 1 0 1 0 8 0 ppxss 1128 3 0 3 2 2 0 1 0 8 0 pffrag 232 6 0 6 3 2 1 1 0 482 1 pffrnode 88 6 0 6 3 2 1 1 0 8 1 pffrent 40 265 0 265 3 2 1 1 0 8 1 pfosfp 40 846 0 423 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 48 0 9 1 0 1 1 0 8 0 pfstkey 112 48 0 9 2 0 2 2 0 8 0 pfstate 328 48 0 9 4 0 4 4 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 291 0 55 16 1 15 16 0 8 0 art_table 32 293 0 55 3 0 3 3 0 8 0 art_node 16 68 0 22 1 0 1 1 0 8 0 sysvmsgpl 40 27 0 15 1 0 1 1 0 8 0 semupl 112 4 0 4 1 1 0 1 0 8 0 semapl 112 52 0 42 1 0 1 1 0 8 0 shmpl 112 65 0 4 2 0 2 2 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1931 0 527 46 0 46 46 0 8 0 ffsino 272 1931 0 527 95 0 95 95 0 8 0 nchpl 144 2680 0 1065 61 0 61 61 0 8 0 uvmvnodes 72 2101 0 0 39 0 39 39 0 8 0 vnodes 208 2101 0 0 111 0 111 111 0 8 0 namei 1024 7345 0 7345 1 0 1 1 0 8 1 percpumem 16 44 0 12 1 0 1 1 0 8 0 vmpool 560 2 0 2 1 1 0 1 0 8 0 scsiplug 64 1 0 1 1 1 0 1 0 8 0 scxspl 192 7742 0 7742 8 7 1 7 0 8 1 plimitpl 152 37 0 30 1 0 1 1 0 8 0 sigapl 432 604 0 593 3 1 2 3 0 8 0 futexpl 56 6774 0 6774 1 0 1 1 0 8 1 knotepl 112 99 0 94 1 0 1 1 0 8 0 kqueuepl 104 122 0 121 1 0 1 1 0 8 0 pipelkpl 48 152 0 144 1 0 1 1 0 8 0 pipepl 120 304 0 293 1 0 1 1 0 8 0 fdescpl 496 605 0 593 3 0 3 3 0 8 0 filepl 152 3991 0 3934 6 1 5 6 0 8 1 lockfpl 104 109 0 109 1 1 0 1 0 8 0 lockfspl 48 38 0 38 1 1 0 1 0 8 0 sessionpl 112 18 0 9 1 0 1 1 0 8 0 pgrppl 48 24 0 15 1 0 1 1 0 8 0 ucredpl 96 243 0 235 1 0 1 1 0 8 0 zombiepl 144 595 0 592 1 0 1 1 0 8 0 processpl 960 621 0 592 5 0 5 5 0 8 0 procpl 624 1360 0 1331 4 0 4 4 0 8 0 sockpl 400 1395 0 1382 7 2 5 5 0 8 2 mcl64k 65536 8 0 0 1 0 1 1 0 8 0 mcl16k 16384 4 0 0 1 0 1 1 0 8 0 mcl12k 12288 5 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 5 0 0 1 0 1 1 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 189 0 0 23 0 23 23 0 8 0 mtagpl 80 37 0 0 1 0 1 1 0 8 0 mbufpl 256 710 0 0 43 0 43 43 0 8 0 bufpl 280 4629 0 192 317 0 317 317 0 8 0 anonpl 16 67412 0 58906 86 11 75 85 0 125 6 amapchunkpl 152 2999 0 2929 10 3 7 9 0 158 0 amappl16 192 2881 0 2438 60 11 49 58 0 8 8 amappl15 184 58 0 55 1 0 1 1 0 8 0 amappl14 176 26 0 25 1 0 1 1 0 8 0 amappl13 168 2 0 2 1 0 1 1 0 8 1 amappl12 160 15 0 13 1 0 1 1 0 8 0 amappl11 152 55 0 47 1 0 1 1 0 8 0 amappl10 144 200 0 195 1 0 1 1 0 8 0 amappl9 136 603 0 600 1 0 1 1 0 8 0 amappl8 128 127 0 105 1 0 1 1 0 8 0 amappl7 120 259 0 249 1 0 1 1 0 8 0 amappl6 112 68 0 59 1 0 1 1 0 8 0 amappl5 104 145 0 133 1 0 1 1 0 8 0 amappl4 96 810 0 779 1 0 1 1 0 8 0 amappl3 88 135 0 127 1 0 1 1 0 8 0 amappl2 80 3496 0 3438 3 1 2 3 0 8 0 amappl1 72 21920 0 21516 25 15 10 20 0 8 0 amappl 80 1614 0 1587 2 0 2 2 0 84 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma128 128 253 0 253 1 1 0 1 0 8 0 dma64 64 6 0 6 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 18 0 17 1 0 1 1 0 8 0 aobjpl 64 66 0 4 1 0 1 1 0 8 0 uaddrrnd 24 607 0 595 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 607 0 595 1 0 1 1 0 8 0 vmmpekpl 168 8229 0 8192 3 0 3 3 0 8 0 vmmpepl 168 78221 0 76840 120 23 97 115 0 357 8 vmsppl 368 606 0 594 2 0 2 2 0 8 0 pdppl 4096 1221 0 1188 6 1 5 6 0 8 0 pvpl 32 213260 0 210313 200 10 190 200 0 265 143 pmappl 232 606 0 594 2 1 1 2 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 214 0 9 6 0 6 6 0 8 0