panic: runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x1 addr=0x78 pc=0x789fc0] goroutine 24 [running]: github.com/google/syzkaller/prog.(*GroupArg).Size(0xc0045c2210, 0xc0045c2210) /syzkaller/gopath/src/github.com/google/syzkaller/prog/prog.go:189 +0x40 github.com/google/syzkaller/prog.foreachArgImpl(0x9a6320, 0xc0045c2210, 0xc0045bda48, 0xc0045c21e0, 0x0, 0x203000, 0xc0030ff808) /syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:143 +0x231 github.com/google/syzkaller/prog.foreachArgImpl(0x9a6360, 0xc0045c21e0, 0xc0045bda48, 0x0, 0x0, 0x9fc000, 0xc0030ff808) /syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:153 +0x3e8 github.com/google/syzkaller/prog.ForeachArg(0xc0045bda40, 0xc0030ff808) /syzkaller/gopath/src/github.com/google/syzkaller/prog/analysis.go:120 +0x9e github.com/google/syzkaller/prog.getCompatibleResources(0xc0045bd940, 0x8f3b6b, 0x7, 0xc00368f9e0, 0x0, 0x0, 0x0) /syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:870 +0xb9 github.com/google/syzkaller/prog.resourceCentric(0xcb2000, 0xc003485180, 0xc00368f9e0, 0x8f0501, 0xc0030ff9f0, 0x448dce, 0xc0030cb3b0) /syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:818 +0xf8 github.com/google/syzkaller/prog.(*ResourceType).generate(0xcb2000, 0xc00368f9e0, 0xc003485180, 0x10, 0x878360, 0xc00361fc50, 0xc00241a700, 0x10) /syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:650 +0x920 github.com/google/syzkaller/prog.(*randGen).generateArgImpl(0xc00368f9e0, 0xc003485180, 0x9acd60, 0xcb2000, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0) /syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:643 +0x506 github.com/google/syzkaller/prog.(*randGen).generateArg(...) /syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:592 github.com/google/syzkaller/prog.(*randGen).generateArgs(0xc00368f9e0, 0xc003485180, 0xc93fa0, 0x1, 0x1, 0xc0030ffd58, 0xb4eadf7b, 0x6dab24d72b9db773, 0xc0030ffd90, 0x78989e, ...) /syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:580 +0x107 github.com/google/syzkaller/prog.(*randGen).generateParticularCall(0xc00368f9e0, 0xc003485180, 0xcbf920, 0x136, 0xc003485180, 0xc0035d3ec0) /syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:524 +0xc6 github.com/google/syzkaller/prog.(*randGen).generateCall(0xc00368f9e0, 0xc003485180, 0xc00365e740, 0xc, 0xc00365e740, 0x0, 0xc003485180) /syzkaller/gopath/src/github.com/google/syzkaller/prog/rand.go:516 +0xb2 github.com/google/syzkaller/prog.(*mutator).insertCall(0xc0030ffec0, 0x14) /syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:137 +0xf2 github.com/google/syzkaller/prog.(*Prog).Mutate(0xc00365e740, 0x9a0c20, 0xc00253f620, 0x1e, 0xc0024f8040, 0xc002f08000, 0x1ea2, 0x2400) /syzkaller/gopath/src/github.com/google/syzkaller/prog/mutation.go:42 +0x29b main.(*Proc).loop(0xc0024f96c0) /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-main-0.c.syzkaller.internal) (tty00) login: kernel: protection fault trap, code=0 Stopped at in_delmulti+0x8d: movl 0xc(%r14),%r15d ddb> set $lines = 0 ddb> set $maxwidth = 0 ddb> show panic the kernel did not panic ddb> trace in_delmulti(fff7f7fffbffffff) at in_delmulti+0x8d sys/netinet/in.c:914 in_purgeaddr(ffff800000a0cd00) at in_purgeaddr+0x156 sys/netinet/in.c:760 in_ifdetach(ffff8000009f5000) at in_ifdetach+0x74 sys/netinet/in.c:969 if_detach(ffff8000009f5000) at if_detach+0x140 sys/net/if.c:1151 tun_clone_destroy(ffff8000009f5000) at tun_clone_destroy+0x172 sys/net/if_tun.c:312 spec_close(ffff800014956740) at spec_close+0x311 sys/kern/spec_vnops.c:555 VOP_CLOSE(fffffd8038439ea0,7,fffffd803f7c69c0,ffff8000ffff84f8) at VOP_CLOSE+0xc0 sys/kern/vfs_vops.c:175 vn_closefile(fffffd802d5d7538,ffff8000ffff84f8) at vn_closefile+0xd3 vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(fffffd802d5d7538,ffff8000ffff84f8) at vn_closefile+0xd3 sys/kern/vfs_vnops.c:610 fdrop(fffffd802d5d7538,ffff8000ffff84f8) at fdrop+0xc2 sys/kern/kern_descrip.c:1273 closef(fffffd802d5d7538,ffff8000ffff84f8) at closef+0x118 sys/kern/kern_descrip.c:1257 fdfree(ffff8000ffff84f8) at fdfree+0x100 sys/kern/kern_descrip.c:1189 exit1(ffff8000ffff84f8,d,1) at exit1+0x32f sys/kern/kern_exit.c:196 postsig(ffff8000ffff84f8,d) at postsig+0x4a6 sigexit sys/kern/kern_sig.c:1499 [inline] postsig(ffff8000ffff84f8,d) at postsig+0x4a6 sys/kern/kern_sig.c:1431 userret(ffff8000ffff84f8) at userret+0x159 sys/kern/kern_sig.c:1889 syscall(ffff800014956bc0) at syscall+0x42e mi_syscall_return sys/sys/syscall_mi.h:115 [inline] syscall(ffff800014956bc0) at syscall+0x42e sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff3880, count: -16 ddb> show registers rdi 0x2 rsi 0 rbp 0xffff800014956570 rbx 0 rdx 0x3 rcx 0x1 rax 0 r8 0xffff800000a0cd00 r9 0x5 r10 0x54a25c260eaebd20 r11 0x90332b8d0f74036b r12 0 r13 0x3 r14 0xfff7f7fffbffffff r15 0x1 rip 0xffffffff81e8490d in_delmulti+0x8d cs 0x8 rflags 0x10246 __ALIGN_SIZE+0xf246 rsp 0xffff800014956510 ss 0x10 in_delmulti+0x8d: movl 0xc(%r14),%r15d ddb> show proc PROC (syz-executor.1) pid=348749 stat=onproc flags process=a proc=2000 pri=73, usrpri=73, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffff89e8,0xffff8000ffff3b50 process=0xffff8000148b2018 user=0xffff800014951000, vmspace=0xfffffd803f012000 estcpu=36, cpticks=0, pctcpu=0.2 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 79401 185759 0 0 3 0x14200 bored sosplice 79850 9488 2824 0 2 0x10008a ksh 2824 415822 95353 0 3 0x92 select sshd 53392 47235 1 0 3 0x100083 ttyin getty 95353 433021 1 0 3 0x80 select sshd 9778 232433 83551 73 3 0x100090 kqread syslogd 83551 93556 1 0 3 0x100082 netio syslogd 81226 36201 1 77 2 0x100090 dhclient 46343 389117 1 0 3 0x80 poll dhclient 60855 114529 0 0 2 0x14200 zerothread 87610 37955 0 0 3 0x14200 aiodoned aiodoned 84687 517417 0 0 3 0x14200 syncer update 31828 247891 0 0 3 0x14200 cleaner cleaner 82900 274334 0 0 3 0x14200 reaper reaper 34981 380366 0 0 3 0x14200 pgdaemon pagedaemon 40649 306826 0 0 3 0x14200 bored crynlk 13163 412610 0 0 3 0x14200 bored crypto 19570 311897 0 0 3 0x40014200 acpi0 acpi0 87315 414257 0 0 2 0x14200 softnet 14354 465748 0 0 2 0x14200 systqmp 34647 346181 0 0 3 0x14200 bored systq 10413 105185 0 0 3 0x40014200 bored softclock 9092 15556 0 0 3 0x40014200 idle0 93832 253516 0 0 3 0x14200 bored smr 1 523752 0 0 2 0x82 init 0 0 -1 0 3 0x10200 scheduler swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9496 6343K 6987K 78643K 11316 0 pcb 13 8K 9K 78643K 101 0 rtable 83 3K 4K 78643K 332 0 ifaddr 63 12K 14K 78643K 145 0 counters 19 16K 16K 78643K 19 0 ioctlops 0 0K 2K 78643K 49 0 iov 0 0K 24K 78643K 114 0 mount 1 1K 1K 78643K 1 0 vnodes 1219 77K 77K 78643K 1467 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 5 0 VM map 2 0K 0K 78643K 2 0 sem 12 1K 1K 78643K 72 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1794 195K 288K 78643K 12646 0 file desc 3 8K 25K 78643K 302 0 sigio 0 0K 0K 78643K 10 0 proc 49 38K 63K 78643K 391 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 12 0 in_multi 31 1K 2K 78643K 44 0 ether_multi 1 0K 0K 78643K 1 0 mrt 0 0K 0K 78643K 2 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 42 185K 185K 78643K 42 0 exec 0 0K 1K 78643K 207 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 70 35K 43K 78643K 1623 0 UVM aobj 16 2K 2K 78643K 18 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 58 0 NDP 11 0K 0K 78643K 27 0 temp 130 3016K 3094K 78643K 5415 0 SYN cache 2 16K 16K 78643K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 7 0 5 1 0 1 1 0 8 0 rtpcb 80 64 0 62 1 0 1 1 0 8 0 rtentry 112 47 0 17 2 0 2 2 0 8 0 unpcb 120 267 0 259 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 259 0 259 1 1 0 1 0 8 0 tcpcb 544 95 0 91 1 0 1 1 0 8 0 ipq 40 5 0 5 1 0 1 1 0 8 1 ipqe 40 57 0 57 1 0 1 1 0 8 1 inpcb 280 832 0 825 5 1 4 4 0 8 3 rttmr 72 1 0 1 1 1 0 1 0 8 0 nd6 48 4 0 2 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 1 0 1 0 8 0 ppxss 1128 11 0 11 1 0 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 212 0 4 14 0 14 14 0 8 0 art_table 32 213 0 4 2 0 2 2 0 8 0 art_node 16 46 0 9 1 0 1 1 0 8 0 sysvmsgpl 40 76 0 39 1 0 1 1 0 8 0 semupl 112 5 0 5 1 1 0 1 0 8 0 semapl 112 66 0 56 1 0 1 1 0 8 0 shmpl 112 16 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1876 0 477 46 0 46 46 0 8 0 ffsino 240 1876 0 477 83 0 83 83 0 8 0 nchpl 144 2494 0 895 60 0 60 60 0 8 0 uvmvnodes 72 2090 0 0 38 0 38 38 0 8 0 vnodes 208 2090 0 0 110 0 110 110 0 8 0 namei 1024 6689 0 6689 1 0 1 1 0 8 1 vcpupl 1984 2 0 0 1 0 1 1 0 8 0 vmpool 528 6 0 4 1 0 1 1 0 8 0 scxspl 192 7355 0 7355 10 7 3 7 0 8 3 plimitpl 152 41 0 34 1 0 1 1 0 8 0 sigapl 432 473 0 462 2 0 2 2 0 8 0 futexpl 56 10349 0 10349 1 0 1 1 0 8 1 knotepl 112 100 0 95 1 0 1 1 0 8 0 kqueuepl 104 104 0 103 1 0 1 1 0 8 0 pipepl 128 392 0 381 2 0 2 2 0 8 1 fdescpl 424 474 0 462 2 0 2 2 0 8 0 filepl 120 3807 0 3744 6 1 5 5 0 8 2 lockfpl 104 146 0 145 1 0 1 1 0 8 0 lockfspl 48 43 0 42 1 0 1 1 0 8 0 sessionpl 112 17 0 7 1 0 1 1 0 8 0 pgrppl 48 20 0 10 1 0 1 1 0 8 0 ucredpl 96 329 0 322 1 0 1 1 0 8 0 zombiepl 144 464 0 461 1 0 1 1 0 8 0 processpl 864 489 0 461 4 0 4 4 0 8 0 procpl 632 887 0 859 5 1 4 5 0 8 0 sosppl 128 5 0 5 1 0 1 1 0 8 1 sockpl 384 1165 0 1148 7 1 6 6 0 8 4 mcl64k 65536 24 0 24 1 0 1 1 0 8 1 mcl16k 16384 8 0 8 1 0 1 1 0 8 1 mcl12k 12288 12 0 12 1 0 1 1 0 8 1 mcl9k 9216 9 0 9 1 0 1 1 0 8 1 mcl8k 8192 18 0 18 1 0 1 1 0 8 1 mcl4k 4096 35 0 35 2 1 1 1 0 8 1 mcl2k2 2112 3 0 3 2 1 1 1 0 8 1 mcl2k 2048 68118 0 68059 19 11 8 16 0 8 0 mtagpl 80 18 0 18 2 1 1 1 0 8 1 mbufpl 256 111832 0 111689 37 18 19 29 0 8 7 bufpl 280 8179 0 2109 435 0 435 435 0 8 0 anonpl 16 66398 0 65170 99 17 82 98 0 62 64 amapchunkpl 152 2513 0 2477 17 6 11 16 0 158 7 amappl16 192 2777 0 2761 58 1 57 58 0 8 51 amappl15 184 50 0 46 1 0 1 1 0 8 0 amappl14 176 30 0 29 1 0 1 1 0 8 0 amappl13 168 3 0 3 1 0 1 1 0 8 1 amappl12 160 5 0 5 1 1 0 1 0 8 0 amappl11 152 48 0 37 1 0 1 1 0 8 0 amappl10 144 10 0 10 1 0 1 1 0 8 1 amappl9 136 555 0 552 1 0 1 1 0 8 0 amappl8 128 121 0 117 1 0 1 1 0 8 0 amappl7 120 89 0 81 1 0 1 1 0 8 0 amappl6 112 68 0 64 1 0 1 1 0 8 0 amappl5 104 154 0 143 1 0 1 1 0 8 0 amappl4 96 690 0 665 1 0 1 1 0 8 0 amappl3 88 136 0 129 1 0 1 1 0 8 0 amappl2 80 2978 0 2920 3 1 2 3 0 8 0 amappl1 72 18103 0 17697 26 16 10 20 0 8 0 amappl 80 1142 0 1119 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 17 0 2 1 0 1 1 0 8 0 uaddrrnd 24 480 0 466 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 480 0 466 1 0 1 1 0 8 0 vmmpekpl 168 7286 0 7261 2 0 2 2 0 8 0 vmmpepl 168 63476 0 62563 138 23 115 130 0 357 64 vmsppl 272 479 0 466 3 1 2 2 0 8 1 pdppl 4096 966 0 934 7 1 6 6 0 8 1 pvpl 32 230103 0 227129 312 7 305 312 0 265 265 pmappl 200 479 0 466 1 0 1 1 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 176 0 34 5 0 5 5 0 8 0