panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/main/kernel/sys/netinet/if_ether.c", line 776 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *484256 80302 0 0x14000 0x40000200 0 softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82726273) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff827a1657,ffffffff827c2b12,308,ffffffff826f4233) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd806230c2c0) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82c09f58) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c09f58) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000fffff308) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: 8 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 "ifp != NULL" failed: file "/syzkaller/managers/main/kernel/sys/netinet/if_ether.c", line 776 ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82726273) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff827a1657,ffffffff827c2b12,308,ffffffff826f4233) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd806230c2c0) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82c09f58) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c09f58) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000fffff308) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800021604880 rbx 0 rdx 0 rcx 0 rax 0xffff8000fffff308 r8 0x101010101010101 r9 0x8080808080808080 r10 0xcf27904e881dfd2a r11 0xcc487261afe995ed r12 0 r13 0xfffffd806eb2a210 r14 0 r15 0x1 rip 0xffffffff815a5488 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021604870 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=484256 stat=onproc flags process=14000 proc=40000200 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000fffff5c0,0xffff8000ffffe838 process=0xffff8000ffffcbd0 user=0xffff8000215ff000, vmspace=0xffffffff82c95238 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 27488 244045 35633 0 2 0 syz-executor.0 27488 154462 35633 0 2 0x4000000 syz-executor.0 80776 81878 3320 0 2 0x2 syz-executor.6 35633 1548 3320 0 3 0x82 nanoslp syz-executor.0 38754 260680 0 0 3 0x14280 nfsidl nfsio 69041 331251 0 0 3 0x14280 nfsidl nfsio 46295 149936 0 0 3 0x14280 nfsidl nfsio 81899 138173 0 0 3 0x14280 nfsidl nfsio 92321 246872 0 0 3 0x14280 nfsidl nfsio 22259 23794 0 0 3 0x14280 nfsidl nfsio 89078 260125 0 0 3 0x14280 nfsidl nfsio 99371 9196 0 0 3 0x14280 nfsidl nfsio 14800 68689 0 0 3 0x14280 nfsidl nfsio 58821 374201 0 0 3 0x14280 nfsidl nfsio 24056 57283 0 0 3 0x14280 nfsidl nfsio 77720 193134 0 0 3 0x14280 nfsidl nfsio 20062 48529 0 0 3 0x14280 nfsidl nfsio 38275 108124 0 0 3 0x14280 nfsidl nfsio 55798 242348 0 0 3 0x14280 nfsidl nfsio 56689 475044 0 0 3 0x14280 nfsidl nfsio 87767 108939 0 0 3 0x14280 nfsidl nfsio 89687 139133 0 0 3 0x14280 nfsidl nfsio 61518 116406 0 0 3 0x14280 nfsidl nfsio 66993 83983 0 0 3 0x14280 nfsidl nfsio 71220 206851 1 0 3 0x100083 ttyin getty 89396 227187 0 0 3 0x14200 bored sosplice 3320 187871 63844 0 3 0x82 thrsleep syz-fuzzer 3320 259854 63844 0 3 0x4000082 nanoslp syz-fuzzer 3320 393479 63844 0 3 0x4000082 wait syz-fuzzer 3320 26225 63844 0 3 0x4000082 thrsleep syz-fuzzer 3320 344375 63844 0 3 0x4000082 thrsleep syz-fuzzer 3320 290811 63844 0 3 0x4000082 wait syz-fuzzer 3320 478485 63844 0 3 0x4000082 wait syz-fuzzer 3320 369734 63844 0 3 0x4000082 wait syz-fuzzer 3320 144992 63844 0 3 0x4000082 wait syz-fuzzer 3320 111821 63844 0 2 0x4000002 syz-fuzzer 3320 22260 63844 0 3 0x4000082 thrsleep syz-fuzzer 3320 512096 63844 0 3 0x4000082 thrsleep syz-fuzzer 3320 504548 63844 0 3 0x4000082 wait syz-fuzzer 3320 426528 63844 0 3 0x4000082 thrsleep syz-fuzzer 63844 428746 57035 0 3 0x10008a sigsusp ksh 57035 400849 67095 0 3 0x9a kqread sshd 67095 481665 1 0 3 0x88 kqread sshd 47471 199629 60857 73 2 0x1100010 syslogd 60857 355216 1 0 3 0x100082 netio syslogd 27031 310510 1 0 3 0x100080 kqread resolvd 51787 263485 25113 77 3 0x100092 kqread dhcpleased 12012 227221 25113 77 3 0x100092 kqread dhcpleased 25113 150258 1 0 3 0x80 kqread dhcpleased 35441 300178 0 0 3 0x14200 bored smr 42060 93707 0 0 2 0x14200 zerothread 63327 327890 0 0 3 0x14200 aiodoned aiodoned 18726 383578 0 0 3 0x14200 syncer update 39069 237196 0 0 3 0x14200 cleaner cleaner 58514 461342 0 0 3 0x14200 reaper reaper 33632 443272 0 0 3 0x14200 pgdaemon pagedaemon 58298 14184 0 0 3 0x14200 bored viomb 56186 438620 0 0 3 0x40014200 acpi0 acpi0 7135 241800 0 0 3 0x14200 bored softnet 39247 513918 0 0 3 0x14200 bored softnet 51445 390056 0 0 3 0x14200 bored softnet 53477 518719 0 0 3 0x14200 bored softnet 69578 138652 0 0 3 0x14200 bored systqmp 65981 113107 0 0 3 0x14200 bored systq *80302 484256 0 0 7 0x40014200 softclock 38668 348214 0 0 3 0x40014200 idle0 1 50243 0 0 3 0x82 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 10209 6412K 6894K 78643K 19605 0 pcb 13 12K 14K 78643K 678 0 rtable 153 7K 10K 78643K 1800 0 ifaddr 61 19K 24K 78643K 534 0 sysctl 2 0K 0K 78643K 2 0 counters 24 16K 17K 78643K 253 0 ioctlops 0 0K 4K 78643K 785 0 iov 0 0K 40K 78643K 873 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1492 93K 94K 78643K 5476 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 18 0 VM map 2 1K 1K 78643K 2 0 sem 20 2K 2K 78643K 216 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 9 29K 77K 78643K 4292 0 sigio 0 0K 0K 78643K 99 0 proc 61 59K 83K 78643K 1414 0 subproc 78 4K 6K 78643K 445 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 204 0 in_multi 52 3K 6K 78643K 510 0 ether_multi 1 0K 0K 78643K 28 0 mrt 1 0K 0K 78643K 27 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 217 970K 970K 78643K 217 0 exec 0 0K 1K 78643K 1439 0 pfkey data 0 0K 0K 78643K 4 0 tdb 3 0K 0K 78643K 3 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 8 62K 64K 78643K 10 0 UVM amap 271 68K 101K 78643K 29014 0 UVM aobj 131 4K 4K 78643K 131 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 184 0 NDP 8 0K 1K 78643K 177 0 temp 104 5769K 6798K 78643K 66437 0 kqueue 12 18K 24K 78643K 411 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 rtpcb 120 451 0 448 7 6 1 3 0 8 0 rtentry 112 529 0 466 5 1 4 4 0 8 0 unpcb 144 3814 0 3801 35 34 1 6 0 8 0 syncache 296 43 0 43 7 7 0 1 0 8 0 tcpqe 32 124 0 124 5 5 0 1 0 8 0 tcpcb 776 1645 0 1641 45 44 1 8 0 8 0 arp 88 84 0 71 1 0 1 1 0 8 0 ipq 40 3 0 3 1 1 0 1 0 8 0 ipqe 40 6 0 6 1 1 0 1 0 8 0 inpcb 336 4436 0 4429 41 40 1 7 0 8 0 nd6 48 109 0 96 1 0 1 1 0 8 0 pkpcb 40 4 0 4 1 1 0 1 0 8 0 kcovpl 48 34 0 28 1 0 1 1 0 8 0 mppekey 1024 3 0 3 1 1 0 1 0 8 0 ppxss 1160 161 0 161 9 9 0 1 0 8 0 pppxif 1360 94 0 94 6 6 0 1 0 8 0 pfstscr 40 157 0 149 1 0 1 1 0 8 0 pfosfp 40 73 0 71 1 0 1 1 0 8 0 pfosfpen 112 73 0 68 1 0 1 1 0 8 0 pfanchor 1280 683 2 213 44 4 40 43 0 8 0 pfstitem 24 26 0 16 1 0 1 1 0 8 0 pfstkey 128 290 0 280 1 0 1 1 0 8 0 pfstate 352 145 0 140 1 0 1 1 0 8 0 rttmr 136 10 0 10 3 3 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 2224 0 1963 45 21 24 29 0 8 2 art_table 32 2225 0 1963 4 0 4 4 0 8 0 art_node 16 528 0 475 1 0 1 1 0 8 0 sysvmsgpl 40 52 0 12 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 207 0 189 1 0 1 1 0 8 0 shmpl 112 128 0 0 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 7378 0 5933 92 0 92 92 0 8 0 ffsino 240 7378 0 5933 86 0 86 86 0 8 0 nchpl 144 14532 0 12904 63 1 62 63 0 8 0 rtmask 32 1 0 1 1 1 0 1 0 8 0 uvmvnodes 80 5926 0 0 121 0 121 121 0 8 0 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 59668 0 59668 8 7 1 3 0 8 1 vmpool 664 16 0 16 5 5 0 1 0 8 0 kstatmem 264 214 0 198 2 0 2 2 0 8 0 scsiplug 72 3 0 3 1 1 0 1 0 8 0 scxspl 216 37277 0 37277 16 15 1 8 0 8 1 plimitpl 152 704 0 690 1 0 1 1 0 8 0 sigapl 424 4579 0 4518 9 1 8 8 0 8 0 futexpl 64 48017 0 48017 2 1 1 1 0 8 1 knotepl 120 51368 0 51308 30 25 5 11 0 8 0 kqueuepl 184 816 0 808 11 10 1 4 0 8 0 pipepl 288 1217 0 1199 22 19 3 7 0 8 0 fdescpl 432 4521 0 4501 4 0 4 4 0 8 0 filepl 120 40359 0 40173 47 39 8 16 0 8 0 lockfpl 104 1351 0 1349 4 3 1 2 0 8 0 lockfspl 48 521 0 519 1 0 1 1 0 8 0 sessionpl 144 52 0 38 1 0 1 1 0 8 0 pgrppl 48 354 0 340 1 0 1 1 0 8 0 ucredpl 104 4898 0 4888 1 0 1 1 0 8 0 zombiepl 144 4526 0 4518 1 0 1 1 0 8 0 processpl 1008 4579 0 4518 12 3 9 9 0 8 0 procpl 696 10992 0 10917 16 7 9 10 0 8 0 sosppl 168 32 0 32 7 7 0 1 0 8 0 sockpl 456 8709 0 8686 207 203 4 28 0 8 1 mcl64k 65536 167 0 167 4 4 0 1 0 8 0 mcl16k 16384 83 0 83 9 9 0 1 0 8 0 mcl12k 12288 183 0 183 5 5 0 1 0 8 0 mcl9k 9216 49 0 49 10 10 0 1 0 8 0 mcl8k 8192 294 0 294 5 5 0 1 0 8 0 mcl4k 4096 576 0 576 4 4 0 1 0 8 0 mcl2k2 2112 26 0 26 9 9 0 1 0 8 0 mcl2k 2048 85184 0 85116 34 24 10 30 0 8 0 mtagpl 96 880 0 880 16 5 11 12 0 8 11 mbufpl 256 180499 0 180312 393 358 35 103 0 8 7 bufpl 288 12008 0 5614 458 0 458 458 0 8 0 anonpl 24 928747 0 913895 218 88 130 136 0 188 16 amapchunkpl 152 92330 0 91744 83 46 37 44 0 158 6 amappl16 200 10742 0 10182 85 52 33 44 0 8 1 amappl15 192 47 0 46 1 0 1 1 0 8 0 amappl14 184 250 0 239 2 1 1 2 0 8 0 amappl13 176 5 0 5 1 1 0 1 0 8 0 amappl12 168 729 0 723 1 0 1 1 0 8 0 amappl11 160 48 0 37 1 0 1 1 0 8 0 amappl10 152 59 0 52 1 0 1 1 0 8 0 amappl9 144 983 0 982 1 0 1 1 0 8 0 amappl8 136 276 0 208 3 0 3 3 0 8 0 amappl7 128 211 0 185 2 0 2 2 0 8 0 amappl6 120 291 0 280 2 1 1 2 0 8 0 amappl5 112 303 0 297 1 0 1 1 0 8 0 amappl4 104 793 0 766 2 1 1 2 0 8 0 amappl3 96 12337 0 12300 2 0 2 2 0 8 0 amappl2 88 5182 0 5117 3 1 2 3 0 8 0 amappl1 80 102729 0 102131 29 13 16 26 0 8 0 amappl 88 28139 0 27996 5 0 5 5 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 72 130 0 0 3 0 3 3 0 8 0 uaddrrnd 24 4537 0 4517 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4537 0 4517 1 0 1 1 0 8 0 vmmpekpl 168 39793 0 39738 3 0 3 3 0 8 0 vmmpepl 168 428411 0 426196 213 83 130 151 0 357 4 vmsppl 344 4536 0 4517 3 0 3 3 0 8 0 rwobjpl 24 116040 0 108438 53 4 49 49 0 8 0 pdppl 4096 9080 0 9034 336 285 51 70 0 8 5 pvpl 32 1864680 0 1845029 483 230 253 360 0 265 57 pmappl 216 4536 0 4517 2 0 2 2 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1551 0 785 26 1 25 25 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82726273) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff827a1657,ffffffff827c2b12,308,ffffffff826f4233) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd806230c2c0) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82c09f58) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c09f58) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000fffff308) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82726273) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff827a1657,ffffffff827c2b12,308,ffffffff826f4233) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd806230c2c0) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff82c09f58) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c09f58) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000fffff308) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7