panic: kernel diagnostic assertion "sc->sc_dev == 0" failed: file "/syzkaller/managers/main/kernel/sys/net/if_tun.c", line 315 Stopped at db_enter+0x1c: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82927b8e) at panic+0x165 sys/kern/subr_prf.c:198 __assert(ffffffff828e10c6,ffffffff8287d56c,13b,ffffffff828c1eb7) at __assert+0x29 sys/kern/subr_prf.c:157 tun_clone_destroy(ffff800000dd9000) at tun_clone_destroy+0x234 sys/net/if_tun.c:315 if_clone_destroy(ffff80003781b960) at if_clone_destroy+0x132 sys/net/if.c:1384 tun_dev_close(45d48,1) at tun_dev_close+0x141 sys/net/if_tun.c:521 spec_close(ffff80003781ba30) at spec_close+0x2d4 sys/kern/spec_vnops.c:538 VOP_CLOSE(fffffd806c95d7d0,1,fffffd807f7d79c0,ffff80002a6a7298) at VOP_CLOSE+0xe2 sys/kern/vfs_vops.c:156 vn_closefile(fffffd8064654888,ffff80002a6a7298) at vn_closefile+0xd5 vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd8064654888,ffff80002a6a7298) at vn_closefile+0xd5 sys/kern/vfs_vnops.c:609 fdrop(fffffd8064654888,ffff80002a6a7298) at fdrop+0xd5 sys/kern/kern_descrip.c:1274 closef(fffffd8064654888,ffff80002a6a7298) at closef+0x11b sys/kern/kern_descrip.c:1258 fdfree(ffff80002a6a7298) at fdfree+0xe3 sys/kern/kern_descrip.c:1190 exit1(ffff80002a6a7298,0,0,1) at exit1+0x387 sys/kern/kern_exit.c:199 sys_exit(ffff80002a6a7298,ffff80003781bda0,ffff80003781bcf0) at sys_exit+0x1a sys/kern/kern_exit.c:89 end trace frame: 0xffff80003781bd90, count: 0 https://www.openbsd.org/ddb.html describes the minimum info required in bug reports. Insufficient info makes it difficult to find and fix bugs. ddb> ddb> set $lines = 0 ddb> set $maxwidth = 0 ddb> show panic *cpu0: kernel diagnostic assertion "sc->sc_dev == 0" failed: file "/syzkaller/managers/main/kernel/sys/net/if_tun.c", line 315 ddb> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82927b8e) at panic+0x165 sys/kern/subr_prf.c:198 __assert(ffffffff828e10c6,ffffffff8287d56c,13b,ffffffff828c1eb7) at __assert+0x29 sys/kern/subr_prf.c:157 tun_clone_destroy(ffff800000dd9000) at tun_clone_destroy+0x234 sys/net/if_tun.c:315 if_clone_destroy(ffff80003781b960) at if_clone_destroy+0x132 sys/net/if.c:1384 tun_dev_close(45d48,1) at tun_dev_close+0x141 sys/net/if_tun.c:521 spec_close(ffff80003781ba30) at spec_close+0x2d4 sys/kern/spec_vnops.c:538 VOP_CLOSE(fffffd806c95d7d0,1,fffffd807f7d79c0,ffff80002a6a7298) at VOP_CLOSE+0xe2 sys/kern/vfs_vops.c:156 vn_closefile(fffffd8064654888,ffff80002a6a7298) at vn_closefile+0xd5 vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd8064654888,ffff80002a6a7298) at vn_closefile+0xd5 sys/kern/vfs_vnops.c:609 fdrop(fffffd8064654888,ffff80002a6a7298) at fdrop+0xd5 sys/kern/kern_descrip.c:1274 closef(fffffd8064654888,ffff80002a6a7298) at closef+0x11b sys/kern/kern_descrip.c:1258 fdfree(ffff80002a6a7298) at fdfree+0xe3 sys/kern/kern_descrip.c:1190 exit1(ffff80002a6a7298,0,0,1) at exit1+0x387 sys/kern/kern_exit.c:199 sys_exit(ffff80002a6a7298,ffff80003781bda0,ffff80003781bcf0) at sys_exit+0x1a sys/kern/kern_exit.c:89 syscall(ffff80003781bda0) at syscall+0x538 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f3bb5a2fe40, count: -16 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80003781b7f0 rbx 0xffffffff81860470 tapclose rdx 0 rcx 0 rax 0xffff80002a6a7298 r8 0 r9 0x8080808080808080 r10 0x83d651300abc3852 r11 0x48849d3e1e15ddaf r12 0 r13 0 r14 0 r15 0x1 rip 0xffffffff811a086c db_enter+0x1c cs 0x8 rflags 0x246 rsp 0xffff80003781b7e0 ss 0 db_enter+0x1c: addq $0x8,%rsp ddb> show proc PROC (syz-executor.1) tid=91961 pid=27494 tcnt=1 stat=onproc flags process=1008 proc=2000 runpri=8, usrpri=86, slppri=8, nice=20 wchan=0x0, wmesg=, ps_single=0xffff80002a6a7298 forw=0xffffffffffffffff, list=0xffff80002a6d5a98,0xffff80002a6a7000 process=0xffff800030f67260 user=0xffff800037816000, vmspace=0xfffffd80691c7888 estcpu=36, cpticks=4, pctcpu=0.0, user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 84237 491203 41049 0 2 0 syz-executor.2 84237 394597 41049 0 2 0x4000000 syz-executor.2 60659 345090 27039 0 2 0 syz-executor.5 60659 376866 27039 0 3 0x4000080 fsleep syz-executor.5 60659 275786 27039 0 3 0x4000080 fsleep syz-executor.5 40189 390556 62707 0 2 0x2 syz-executor.7 24887 359045 0 0 3 0x14280 nfsidl nfsio 3437 142510 0 0 3 0x14280 nfsidl nfsio 20771 223000 0 0 3 0x14280 nfsidl nfsio 29087 80227 0 0 3 0x14280 nfsidl nfsio 4912 355750 0 0 3 0x14280 nfsidl nfsio 28865 184909 0 0 3 0x14280 nfsidl nfsio 88980 79916 0 0 3 0x14280 nfsidl nfsio 67951 441338 0 0 3 0x14280 nfsidl nfsio 57196 268045 0 0 3 0x14280 nfsidl nfsio 99106 477720 0 0 3 0x14280 nfsidl nfsio 89568 6394 0 0 3 0x14280 nfsidl nfsio 27072 218669 0 0 3 0x14280 nfsidl nfsio 18826 482438 0 0 3 0x14280 nfsidl nfsio 23377 129379 0 0 3 0x14280 nfsidl nfsio 40536 381255 0 0 3 0x14280 nfsidl nfsio 56 116315 0 0 3 0x14280 nfsidl nfsio 93996 318813 0 0 3 0x14280 nfsidl nfsio 99101 174978 0 0 3 0x14280 nfsidl nfsio 79345 275543 0 0 3 0x14280 nfsidl nfsio 47704 118088 0 0 3 0x14280 nfsidl nfsio 79743 333940 62707 0 2 0x2 syz-executor.4 27039 275907 62707 0 3 0x82 nanoslp syz-executor.5 14474 150968 0 0 3 0x14200 bored sosplice 23786 516213 62707 0 2 0x2 syz-executor.6 41049 11051 62707 0 3 0x82 nanoslp syz-executor.2 23862 312982 62707 0 2 0x482 syz-executor.1 4156 7398 62707 0 2 0x482 syz-executor.3 72432 475547 62707 0 2 0x2 syz-executor.0 62707 354271 76505 0 3 0x1a000082 wait syz-fuzzer 62707 388668 76505 0 3 0x1e000082 nanoslp syz-fuzzer 62707 286914 76505 0 3 0x1e000082 wait syz-fuzzer 62707 232552 76505 0 3 0x1e000082 wait syz-fuzzer 62707 35238 76505 0 3 0x1e000082 thrsleep syz-fuzzer 62707 10939 76505 0 3 0x1e000082 wait syz-fuzzer 62707 311778 76505 0 3 0x1e000082 thrsleep syz-fuzzer 62707 170406 76505 0 3 0x1e000082 wait syz-fuzzer 62707 292261 76505 0 3 0x1e000082 kqread syz-fuzzer 62707 196019 76505 0 3 0x1e000082 thrsleep syz-fuzzer 62707 465695 76505 0 3 0x1e000082 thrsleep syz-fuzzer 62707 109148 76505 0 3 0x1e000082 wait syz-fuzzer 62707 490741 76505 0 3 0x1e000082 wait syz-fuzzer 62707 103707 76505 0 3 0x1e000082 wait syz-fuzzer 76505 443072 86863 0 3 0x810008a sigsusp ksh 86863 50089 16884 0 3 0x1800009a kqread sshd 91939 524132 1 0 3 0x18100083 ttyin getty 16884 229922 1 0 3 0x18000088 kqread sshd 2417 55253 84745 73 3 0x19100090 kqread syslogd 84745 104757 1 0 3 0x18100082 netio syslogd 33712 461464 1 0 3 0x18100080 kqread resolvd 87334 268921 56119 77 3 0x18100092 kqread dhcpleased 34770 358451 56119 77 3 0x18100092 kqread dhcpleased 56119 181459 1 0 3 0x18000080 kqread dhcpleased 65335 259820 0 0 3 0x14200 bored smr 34866 203297 0 0 2 0x14200 zerothread 9928 488908 0 0 3 0x14200 aiodoned aiodoned 7952 214704 0 0 3 0x14200 syncer update 41963 418465 0 0 3 0x14200 cleaner cleaner 88829 103443 0 0 3 0x14200 reaper reaper 81577 173939 0 0 3 0x14200 pgdaemon pagedaemon 43188 280836 0 0 3 0x14200 bored viomb 40904 23013 0 0 3 0x40014200 acpi0 acpi0 1483 178643 0 0 3 0x14200 bored softnet3 58688 103075 0 0 3 0x14200 bored softnet2 10343 38081 0 0 3 0x14200 bored softnet1 66031 142046 0 0 3 0x14200 bored softnet0 9438 394455 0 0 3 0x14200 bored systqmp 5604 63373 0 0 3 0x14200 bored systq 48528 229898 0 0 3 0x40014200 tmoslp softclock 49690 189078 0 0 3 0x40014200 idle0 1 426113 0 0 3 0x8000082 wait 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 10193 6404K 6809K 166960K 14388 0 pcb 15 11K 12K 166960K 198 0 rtable 174 9K 10K 166960K 672 0 pf 29 8K 9K 166960K 113 0 ifaddr 34 9K 11K 166960K 105 0 ifgroup 50 2K 2K 166960K 172 0 sysctl 3 0K 0K 166960K 3 0 counters 30 17K 17K 166960K 68 0 ioctlops 0 0K 2K 166960K 142 0 iov 0 0K 14K 166960K 143 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1558 98K 98K 166960K 2577 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 9K 166960K 34 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 276 0 dirhash 12 2K 2K 166960K 21 0 ACPI 1697 195K 286K 166960K 12548 0 file desc 13 45K 73K 166960K 1853 0 sigio 0 0K 0K 166960K 99 0 proc 57 59K 75K 166960K 738 0 subproc 104 6K 6K 166960K 182 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 91 0 in_multi 66 4K 7K 166960K 183 0 ether_multi 1 0K 0K 166960K 4 0 mrt 0 0K 0K 166960K 6 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 211 943K 943K 166960K 211 0 exec 0 0K 1K 166960K 869 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 344 184K 185K 166960K 18963 0 UVM aobj 108 3K 3K 166960K 108 0 pinsyscall 22 44K 100K 166960K 1383 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 33 0 NDP 11 0K 1K 166960K 77 0 temp 74 6804K 6884K 166960K 12388 0 kqueue 12 18K 26K 166960K 178 0 SYN cache 2 16K 16K 166960K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 135 0 132 2 0 2 2 0 8 1 rtentry 112 195 0 118 4 0 4 4 0 8 0 unpcb 144 1296 0 1283 9 3 6 6 0 8 5 syncache 336 19 0 19 2 1 1 1 0 8 1 tcpqe 32 649 0 649 3 2 1 2 0 8 1 tcpcb 808 726 0 708 15 6 9 9 0 8 6 arp 88 36 0 24 1 0 1 1 0 8 0 ipq 40 1 0 1 1 0 1 1 0 8 1 ipqe 40 67 0 67 1 0 1 1 0 8 1 inpcb 360 1734 0 1713 21 10 11 15 0 8 8 nd6 104 44 0 29 1 0 1 1 0 8 0 pkpcb 40 8 0 8 2 1 1 1 0 8 1 kcovpl 48 14 0 6 1 0 1 1 0 8 0 ppxss 1072 19 0 19 2 1 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 765 0 436 29 1 28 29 0 8 4 art_table 32 766 0 436 4 0 4 4 0 8 0 art_node 16 194 0 124 1 0 1 1 0 8 0 sysvmsgpl 40 30 0 17 1 0 1 1 0 8 0 semapl 112 274 0 264 1 0 1 1 0 8 0 shmpl 112 105 0 0 3 0 3 3 0 8 0 dirhash 1024 23 0 6 3 0 3 3 0 8 0 dino2pl 256 4024 0 2506 96 0 96 96 0 8 0 ffsino 240 4024 0 2506 90 0 90 90 0 8 0 nchpl 144 6588 0 4857 66 0 66 66 0 8 0 uvmvnodes 80 4858 0 0 100 0 100 100 0 8 0 vnodes 216 4858 0 0 270 0 270 270 0 8 0 namei 1024 22054 0 22050 3 1 2 2 0 8 1 vcpupl 2048 78 0 0 10 0 10 10 0 8 0 vmpool 664 78 0 0 7 0 7 7 0 8 0 kstatmem 264 98 0 76 2 0 2 2 0 8 0 scxspl 216 21328 0 21328 11 7 4 8 1 8 4 plimitpl 152 390 0 375 1 0 1 1 0 8 0 sigapl 424 2319 0 2257 8 0 8 8 0 8 0 futexpl 64 16982 0 16980 2 1 1 1 0 8 0 knotepl 120 20060 0 19978 15 5 10 11 0 8 4 kqueuepl 184 409 0 401 6 0 6 6 0 8 5 pipepl 288 498 0 469 7 0 7 7 0 8 4 fdescpl 432 2122 0 2097 4 0 4 4 0 8 0 filepl 120 13094 0 12854 20 5 15 15 0 8 7 lockfpl 104 372 0 370 2 1 1 2 0 8 0 lockfspl 48 98 0 96 1 0 1 1 0 8 0 sessionpl 144 29 0 13 1 0 1 1 0 8 0 pgrppl 48 106 0 90 1 0 1 1 0 8 0 ucredpl 104 2064 0 2054 1 0 1 1 0 8 0 zombiepl 144 2259 0 2257 1 0 1 1 0 8 0 processpl 1072 2319 0 2257 5 0 5 5 0 8 0 procpl 680 4937 0 4859 9 0 9 9 0 8 1 sosppl 168 8 0 6 2 1 1 1 0 8 0 sockpl 488 3173 0 3136 57 43 14 23 0 8 8 mcl64k 65536 76 0 76 2 1 1 1 0 8 1 mcl16k 16384 57 0 57 1 0 1 1 0 8 1 mcl12k 12288 93 0 93 2 1 1 1 0 8 1 mcl9k 9216 37 0 37 2 1 1 1 0 8 1 mcl8k 8192 222 0 222 2 1 1 1 0 8 1 mcl4k 4096 200 0 200 2 1 1 1 0 8 1 mcl2k2 2112 12 0 12 1 0 1 1 0 8 1 mcl2k 2048 70446 0 70385 65 50 15 37 0 8 5 mtagpl 96 157 0 64 3 0 3 3 0 8 0 mbufpl 256 130725 0 130523 76 52 24 61 0 8 6 bufpl 280 7463 0 1124 453 0 453 453 0 8 0 anonpl 24 358427 0 344809 114 6 108 108 0 188 23 amapchunkpl 152 60846 0 60048 40 3 37 37 0 158 1 amappl16 200 8898 0 8470 38 5 33 35 0 8 8 amappl15 192 34 0 33 1 0 1 1 0 8 0 amappl14 184 167 0 157 2 1 1 2 0 8 0 amappl13 176 18 0 16 1 0 1 1 0 8 0 amappl12 168 2844 0 2817 2 0 2 2 0 8 0 amappl11 160 55 0 45 1 0 1 1 0 8 0 amappl10 152 47 0 38 1 0 1 1 0 8 0 amappl9 144 298 0 296 1 0 1 1 0 8 0 amappl8 136 184 0 125 3 0 3 3 0 8 0 amappl7 128 56 0 46 1 0 1 1 0 8 0 amappl6 120 407 0 389 2 0 2 2 0 8 0 amappl5 112 222 0 210 1 0 1 1 0 8 0 amappl4 104 606 0 571 2 0 2 2 0 8 0 amappl3 96 11952 0 11880 3 0 3 3 0 8 0 amappl2 88 2602 0 2532 4 2 2 4 0 8 0 amappl1 80 15895 0 15404 22 10 12 22 0 8 0 amappl 88 18315 0 18103 6 0 6 6 0 92 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 1 0 0 1 0 1 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 72 107 0 0 2 0 2 2 0 8 0 uaddrrnd 24 2200 0 2097 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2200 0 2097 1 0 1 1 0 8 0 vmmpekpl 168 19342 0 19280 4 0 4 4 0 8 0 vmmpepl 168 147908 0 145703 182 61 121 156 0 357 12 vmsppl 352 2199 0 2097 10 0 10 10 0 8 0 rwobjpl 24 46472 0 40090 39 0 39 39 0 8 0 pdppl 4096 4406 0 4272 257 119 138 142 0 8 4 pvpl 32 850667 0 831712 430 237 193 388 0 265 32 pmappl 216 2199 0 2097 6 0 6 6 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 673 0 235 14 0 14 14 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82927b8e) at panic+0x165 sys/kern/subr_prf.c:198 __assert(ffffffff828e10c6,ffffffff8287d56c,13b,ffffffff828c1eb7) at __assert+0x29 sys/kern/subr_prf.c:157 tun_clone_destroy(ffff800000dd9000) at tun_clone_destroy+0x234 sys/net/if_tun.c:315 if_clone_destroy(ffff80003781b960) at if_clone_destroy+0x132 sys/net/if.c:1384 tun_dev_close(45d48,1) at tun_dev_close+0x141 sys/net/if_tun.c:521 spec_close(ffff80003781ba30) at spec_close+0x2d4 sys/kern/spec_vnops.c:538 VOP_CLOSE(fffffd806c95d7d0,1,fffffd807f7d79c0,ffff80002a6a7298) at VOP_CLOSE+0xe2 sys/kern/vfs_vops.c:156 vn_closefile(fffffd8064654888,ffff80002a6a7298) at vn_closefile+0xd5 vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd8064654888,ffff80002a6a7298) at vn_closefile+0xd5 sys/kern/vfs_vnops.c:609 fdrop(fffffd8064654888,ffff80002a6a7298) at fdrop+0xd5 sys/kern/kern_descrip.c:1274 closef(fffffd8064654888,ffff80002a6a7298) at closef+0x11b sys/kern/kern_descrip.c:1258 fdfree(ffff80002a6a7298) at fdfree+0xe3 sys/kern/kern_descrip.c:1190 exit1(ffff80002a6a7298,0,0,1) at exit1+0x387 sys/kern/kern_exit.c:199 sys_exit(ffff80002a6a7298,ffff80003781bda0,ffff80003781bcf0) at sys_exit+0x1a sys/kern/kern_exit.c:89 syscall(ffff80003781bda0) at syscall+0x538 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f3bb5a2fe40, count: -16 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x1c sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82927b8e) at panic+0x165 sys/kern/subr_prf.c:198 __assert(ffffffff828e10c6,ffffffff8287d56c,13b,ffffffff828c1eb7) at __assert+0x29 sys/kern/subr_prf.c:157 tun_clone_destroy(ffff800000dd9000) at tun_clone_destroy+0x234 sys/net/if_tun.c:315 if_clone_destroy(ffff80003781b960) at if_clone_destroy+0x132 sys/net/if.c:1384 tun_dev_close(45d48,1) at tun_dev_close+0x141 sys/net/if_tun.c:521 spec_close(ffff80003781ba30) at spec_close+0x2d4 sys/kern/spec_vnops.c:538 VOP_CLOSE(fffffd806c95d7d0,1,fffffd807f7d79c0,ffff80002a6a7298) at VOP_CLOSE+0xe2 sys/kern/vfs_vops.c:156 vn_closefile(fffffd8064654888,ffff80002a6a7298) at vn_closefile+0xd5 vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd8064654888,ffff80002a6a7298) at vn_closefile+0xd5 sys/kern/vfs_vnops.c:609 fdrop(fffffd8064654888,ffff80002a6a7298) at fdrop+0xd5 sys/kern/kern_descrip.c:1274 closef(fffffd8064654888,ffff80002a6a7298) at closef+0x11b sys/kern/kern_descrip.c:1258 fdfree(ffff80002a6a7298) at fdfree+0xe3 sys/kern/kern_descrip.c:1190 exit1(ffff80002a6a7298,0,0,1) at exit1+0x387 sys/kern/kern_exit.c:199 sys_exit(ffff80002a6a7298,ffff80003781bda0,ffff80003781bcf0) at sys_exit+0x1a sys/kern/kern_exit.c:89 syscall(ffff80003781bda0) at syscall+0x538 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f3bb5a2fe40, count: -16