panic: runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x1 addr=0xa0 pc=0x7a0da1] goroutine 39 [running]: github.com/google/syzkaller/prog.chooseCall.func1(0x9a7880, 0xc0020761a0, 0xc0020e03c0) /syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:198 +0x51 github.com/google/syzkaller/prog.foreachArgImpl(0x9a7880, 0xc0020761a0, 0xc002065908, 0x0, 0x0, 0x0, 0xc0003a3d60) /syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:125 +0xbe github.com/google/syzkaller/prog.ForeachArg(0xc002065900, 0xc0003a3d60) /syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:120 +0x9e github.com/google/syzkaller/prog.chooseCall(0xc001f0e5c0, 0xc002076b20, 0xc002098d80, 0xc0003a3dc0) /syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:197 +0x10d github.com/google/syzkaller/prog.(*mutator).mutateArg(0xc0003a3ec0, 0xa) /syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:161 +0x67 github.com/google/syzkaller/prog.(*Prog).Mutate(0xc001f0e5c0, 0x9a2180, 0xc002ba5860, 0x1e, 0xc0031540c0, 0xc00282a000, 0x1e6b, 0x2400) /syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:44 +0x2da main.(*Proc).loop(0xc003154100) /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-7.c.syzkaller.internal) (tty00) login: kernel: protection 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 the kernel did not panic ddb{0}> trace in_delmulti(fffeffffffffffff) at in_delmulti+0x8d sys/netinet/in.c:914 in_purgeaddr(ffff800000b03600) at in_purgeaddr+0x156 sys/netinet/in.c:760 in_ifdetach(ffff8000009d0000) at in_ifdetach+0x74 sys/netinet/in.c:969 if_detach(ffff8000009d0000) at if_detach+0x140 sys/net/if.c:1150 tun_clone_destroy(ffff8000009d0000) at tun_clone_destroy+0x1f2 sys/net/if_tun.c:329 tun_dev_close(5d00,7) at tun_dev_close+0x160 sys/net/if_tun.c:480 spec_close(ffff800023d9b090) at spec_close+0x311 sys/kern/spec_vnops.c:555 VOP_CLOSE(fffffd806ed8a418,7,fffffd807f7bf8a0,ffff800020ac6c48) at VOP_CLOSE+0xc0 sys/kern/vfs_vops.c:174 vn_closefile(fffffd8066df94d8,ffff800020ac6c48) at vn_closefile+0xd7 vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(fffffd8066df94d8,ffff800020ac6c48) at vn_closefile+0xd7 sys/kern/vfs_vnops.c:614 fdrop(fffffd8066df94d8,ffff800020ac6c48) at fdrop+0xc2 sys/kern/kern_descrip.c:1276 closef(fffffd8066df94d8,ffff800020ac6c48) at closef+0x11c sys/kern/kern_descrip.c:1260 fdfree(ffff800020ac6c48) at fdfree+0x101 sys/kern/kern_descrip.c:1192 exit1(ffff800020ac6c48,0,d,1) at exit1+0x344 sys/kern/kern_exit.c:196 postsig(ffff800020ac6c48,d) at postsig+0x4e5 sigexit sys/kern/kern_sig.c:1444 [inline] postsig(ffff800020ac6c48,d) at postsig+0x4e5 sys/kern/kern_sig.c:1376 userret(ffff800020ac6c48) at userret+0x199 sys/kern/kern_sig.c:1828 syscall(ffff800023d9b510) at syscall+0x55f mi_syscall_return sys/sys/syscall_mi.h:129 [inline] syscall(ffff800023d9b510) at syscall+0x55f sys/arch/amd64/amd64/trap.c:592 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd4970, count: -17 ddb{0}> show registers rdi 0x2 rsi 0 rbp 0xffff800023d9ae60 rbx 0 rdx 0xffff800020ac6c48 rcx 0 rax 0 r8 0xffffffff81165f73 rt_ifa_purge+0x153 r9 0x5 r10 0x2f r11 0xfc0fd125133d7b0e r12 0 r13 0x3 r14 0xfffeffffffffffff r15 0x1 rip 0xffffffff820cbd9d in_delmulti+0x8d cs 0x8 rflags 0x10246 __ALIGN_SIZE+0xf246 rsp 0xffff800023d9ae00 ss 0x10 in_delmulti+0x8d: movl 0xc(%r14),%r15d ddb{0}> show proc PROC (syz-executor.0) pid=162841 stat=onproc flags process=a proc=2000 pri=32, usrpri=77, nice=20 forw=0xffffffffffffffff, list=0xffff800020ac6018,0xffff800020ac6ec8 process=0xffff800020a92f20 user=0xffff800023d96000, vmspace=0xfffffd807f000a10 estcpu=36, cpticks=4, pctcpu=0.26 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 51369 9419 0 0 3 0x14200 bored sosplice 71259 113546 9662 0 2 0x100002 ksh 9662 161820 61680 0 3 0x92 select sshd 87824 322628 1 0 3 0x100083 ttyin getty 61680 290172 1 0 3 0x80 select sshd 4066 102975 41344 74 3 0x100092 bpf pflogd 41344 265069 1 0 3 0x80 netio pflogd 50400 53147 11157 73 3 0x100090 kqread syslogd 11157 213513 1 0 3 0x100082 netio syslogd 32871 224746 1 77 2 0x100090 dhclient 90201 107644 1 0 3 0x80 poll dhclient 88264 54640 0 0 3 0x14200 bored smr 83845 177244 0 0 3 0x14200 pgzero zerothread 85341 102326 0 0 3 0x14200 aiodoned aiodoned 49905 194695 0 0 3 0x14200 syncer update 36046 428349 0 0 3 0x14200 cleaner cleaner 73231 438225 0 0 3 0x14200 reaper reaper 29669 396283 0 0 3 0x14200 pgdaemon pagedaemon 33892 520271 0 0 3 0x14200 bored crynlk 55508 89456 0 0 3 0x14200 bored crypto 5877 241615 0 0 3 0x40014200 acpi0 acpi0 98244 460987 0 0 3 0x40014200 idle1 64116 376326 0 0 3 0x14200 bored softnet 79248 422560 0 0 2 0x14200 systqmp 46288 438481 0 0 3 0x14200 bored systq 70288 232641 0 0 3 0x40014200 bored softclock 37417 61180 0 0 3 0x40014200 idle0 1 278677 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 9543 6432K 7898K 78643K 12141 0 pcb 13 8K 8K 78643K 214 0 rtable 105 4K 4K 78643K 370 0 ifaddr 86 15K 17K 78643K 140 0 counters 43 33K 34K 78643K 53 0 ioctlops 0 0K 4K 78643K 1500 0 iov 0 0K 16K 78643K 97 0 mount 1 1K 1K 78643K 1 0 vnodes 1232 77K 77K 78643K 1742 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 1K 1K 78643K 45 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 3 8K 25K 78643K 359 0 sigio 0 0K 0K 78643K 13 0 proc 64 63K 95K 78643K 537 0 subproc 14 0K 2K 78643K 68 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 38 0 in_multi 82 4K 4K 78643K 137 0 ether_multi 1 0K 0K 78643K 11 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 97 440K 440K 78643K 97 0 exec 0 0K 1K 78643K 251 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 74 36K 39K 78643K 2216 0 UVM aobj 19 5K 5K 78643K 25 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 78 0 NDP 15 0K 0K 78643K 29 0 temp 144 3031K 3095K 78643K 6416 0 kqueue 2 2K 10K 78643K 23 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 11 0 7 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 49 0 47 1 0 1 1 0 8 0 rtentry 112 73 0 32 2 0 2 2 0 8 0 unpcb 120 337 0 327 3 1 2 2 0 8 1 syncache 264 11 0 11 3 2 1 1 0 8 1 tcpqe 32 316 0 316 2 2 0 2 0 8 0 tcpcb 544 230 0 226 2 0 2 2 0 8 1 inpcb 280 841 0 834 2 0 2 2 0 8 1 nd6 48 13 0 7 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 1 0 1 0 8 0 swfcl 56 2 0 0 1 0 1 1 0 8 0 pffrag 232 10 0 10 2 1 1 1 0 482 1 pffrnode 88 10 0 10 2 1 1 1 0 8 1 pffrent 40 280 0 280 2 1 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 64 0 10 1 0 1 1 0 8 0 pfstkey 112 64 0 10 2 0 2 2 0 8 0 pfstate 328 64 0 9 5 0 5 5 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 256 310 0 112 13 0 13 13 0 8 0 art_table 32 312 0 112 2 0 2 2 0 8 0 art_node 16 72 0 30 1 0 1 1 0 8 0 sysvmsgpl 40 34 0 18 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 43 0 33 1 0 1 1 0 8 0 shmpl 112 23 0 6 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1883 0 477 46 0 46 46 0 8 0 ffsino 272 1883 0 477 95 0 95 95 0 8 0 nchpl 144 2551 0 954 61 0 61 61 0 8 0 uvmvnodes 72 2377 0 0 44 0 44 44 0 8 0 vnodes 208 2377 0 0 126 0 126 126 0 8 0 namei 1024 7869 0 7869 1 0 1 1 0 8 1 percpumem 16 37 0 5 1 0 1 1 0 8 0 vcpupl 1984 2 0 0 1 0 1 1 0 8 0 vmpool 560 4 0 2 2 1 1 1 0 8 0 scxspl 192 8094 0 8094 7 6 1 6 0 8 1 plimitpl 152 52 0 44 1 0 1 1 0 8 0 sigapl 424 569 0 539 4 0 4 4 0 8 0 futexpl 56 7423 0 7423 1 0 1 1 0 8 1 knotepl 112 102 0 97 1 0 1 1 0 8 0 kqueuepl 144 89 0 88 1 0 1 1 0 8 0 pipelkpl 48 156 0 148 1 0 1 1 0 8 0 pipepl 120 312 0 301 2 1 1 2 0 8 0 fdescpl 496 553 0 539 3 0 3 3 0 8 0 filepl 152 4435 0 4367 7 0 7 7 0 8 3 lockfpl 104 160 0 159 1 0 1 1 0 8 0 lockfspl 48 39 0 38 1 0 1 1 0 8 0 sessionpl 112 20 0 9 1 0 1 1 0 8 0 pgrppl 48 22 0 11 1 0 1 1 0 8 0 ucredpl 96 547 0 538 1 0 1 1 0 8 0 zombiepl 144 541 0 538 1 0 1 1 0 8 0 processpl 960 569 0 538 5 0 5 5 0 8 0 procpl 624 1341 0 1310 4 0 4 4 0 8 0 srpgc 64 2 0 2 1 0 1 1 0 8 1 sosppl 128 16 0 16 2 1 1 1 0 8 1 sockpl 400 1242 0 1223 7 0 7 7 0 8 4 mcl64k 65536 13 0 0 2 0 2 2 0 8 0 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 4 0 0 1 0 1 1 0 8 0 mcl9k 9216 3 0 0 1 0 1 1 0 8 0 mcl8k 8192 9 0 0 2 0 2 2 0 8 0 mcl4k 4096 9 0 0 2 0 2 2 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 230 0 0 28 0 28 28 0 8 0 mtagpl 80 61 0 0 2 0 2 2 0 8 0 mbufpl 256 318 0 0 19 0 19 19 0 8 0 bufpl 280 5025 0 175 347 0 347 347 0 8 0 anonpl 16 74192 0 72870 86 1 85 85 0 124 61 amapchunkpl 152 3349 0 3310 10 3 7 10 0 158 4 amappl16 192 2660 0 2644 61 13 48 60 0 8 37 amappl15 184 225 0 223 1 0 1 1 0 8 0 amappl14 176 16 0 15 2 1 1 1 0 8 0 amappl13 168 37 0 36 1 0 1 1 0 8 0 amappl12 160 136 0 136 2 1 1 1 0 8 1 amappl11 152 83 0 65 1 0 1 1 0 8 0 amappl10 144 19 0 17 1 0 1 1 0 8 0 amappl9 136 393 0 390 1 0 1 1 0 8 0 amappl8 128 374 0 371 2 0 2 2 0 8 1 amappl7 120 137 0 128 1 0 1 1 0 8 0 amappl6 112 28 0 28 2 1 1 1 0 8 1 amappl5 104 559 0 543 1 0 1 1 0 8 0 amappl4 96 553 0 522 2 1 1 2 0 8 0 amappl3 88 127 0 120 1 0 1 1 0 8 0 amappl2 80 3502 0 3443 3 1 2 3 0 8 0 amappl1 72 22369 0 21943 26 16 10 20 0 8 0 amappl 80 1628 0 1602 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 24 0 6 1 0 1 1 0 8 0 uaddrrnd 24 557 0 541 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 557 0 541 1 0 1 1 0 8 0 vmmpekpl 168 8354 0 8323 2 0 2 2 0 8 0 vmmpepl 168 76323 0 75358 146 17 129 129 0 357 75 vmsppl 368 556 0 541 2 0 2 2 0 8 0 pdppl 4096 1122 0 1084 6 0 6 6 0 8 0 pvpl 32 226666 0 223506 204 0 204 204 0 265 134 pmappl 232 556 0 541 3 1 2 2 0 8 1 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 193 0 3 6 0 6 6 0 8 0