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 *219131 63066 0 0x14000 0x40000200 0 softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff825814d2) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff825f66a4,ffffffff8261512d,308,ffffffff82551571) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd8069f675c0) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff829bfca8) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff829bfca8) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000fffff500) 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(ffffffff825814d2) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff825f66a4,ffffffff8261512d,308,ffffffff82551571) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd8069f675c0) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff829bfca8) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff829bfca8) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000fffff500) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800021684990 rbx 0 rdx 0 rcx 0 rax 0xffff8000fffff500 r8 0x101010101010101 r9 0x8080808080808080 r10 0xa22e1c0975c5a6b2 r11 0xc372aa84e370409c r12 0 r13 0xfffffd806ebc3688 r14 0 r15 0x1 rip 0xffffffff824b4ec8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021684980 ss 0 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softclock) pid=219131 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff8000fffff7a0,0xffff8000fffff270 process=0xffff8000ffffc000 user=0xffff80002167f000, vmspace=0xffffffff829c3c38 estcpu=1, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 99995 404953 89316 0 2 0 syz-executor.6 23717 505522 23512 0 2 0 syz-executor.3 23717 296009 23512 0 3 0x4000080 fsleep syz-executor.3 23717 245080 23512 0 3 0x4000080 fsleep syz-executor.3 23717 127990 23512 0 3 0x4000080 fsleep syz-executor.3 98462 271157 28553 0 2 0 syz-executor.0 98462 236806 28553 0 3 0x4000080 fsleep syz-executor.0 44909 10109 98973 0 2 0 syz-executor.2 44909 436116 98973 0 3 0x4000080 fsleep syz-executor.2 29348 461462 62369 0 2 0 syz-executor.5 29348 397501 62369 0 2 0x4000000 syz-executor.5 59294 408284 48155 0 2 0 syz-executor.7 59294 52249 48155 0 2 0x4000000 syz-executor.7 59294 350759 48155 0 3 0x4000080 kqpoll syz-executor.7 59294 403967 48155 0 3 0x4000080 fsleep syz-executor.7 42885 494587 98421 0 2 0x482 syz-executor.4 62369 231089 98421 0 2 0x482 syz-executor.5 23512 298286 98421 0 2 0x482 syz-executor.3 98973 349675 98421 0 2 0x482 syz-executor.2 28553 513276 98421 0 2 0x482 syz-executor.0 89316 70221 98421 0 2 0x482 syz-executor.6 94719 432269 0 0 3 0x14200 acct acct 48155 464494 98421 0 2 0x482 syz-executor.7 97695 397977 1 0 3 0x100083 ttyin getty 52720 476695 0 0 3 0x14280 nfsidl nfsio 10953 85887 0 0 3 0x14280 nfsidl nfsio 93875 344331 0 0 3 0x14280 nfsidl nfsio 68101 406824 0 0 3 0x14280 nfsidl nfsio 63075 117190 0 0 3 0x14280 nfsidl nfsio 41610 187625 0 0 3 0x14280 nfsidl nfsio 91935 48932 0 0 3 0x14280 nfsidl nfsio 58308 431460 0 0 3 0x14280 nfsidl nfsio 68844 416727 0 0 3 0x14280 nfsidl nfsio 93227 210098 0 0 3 0x14280 nfsidl nfsio 57986 242272 0 0 3 0x14280 nfsidl nfsio 93356 311029 0 0 3 0x14280 nfsidl nfsio 96330 41654 0 0 3 0x14280 nfsidl nfsio 65647 6877 0 0 3 0x14280 nfsidl nfsio 71800 5560 0 0 3 0x14280 nfsidl nfsio 19286 388933 0 0 3 0x14280 nfsidl nfsio 7705 244703 0 0 3 0x14280 nfsidl nfsio 96936 434168 0 0 3 0x14280 nfsidl nfsio 41597 320762 0 0 3 0x14280 nfsidl nfsio 8607 501584 0 0 3 0x14280 nfsidl nfsio 86269 152048 0 0 3 0x14200 bored sosplice 98421 464842 22429 0 3 0x82 thrsleep syz-fuzzer 98421 184993 22429 0 3 0x4000082 thrsleep syz-fuzzer 98421 467338 22429 0 3 0x4000082 wait syz-fuzzer 98421 249494 22429 0 3 0x4000082 wait syz-fuzzer 98421 31099 22429 0 3 0x4000082 thrsleep syz-fuzzer 98421 512901 22429 0 3 0x4000082 thrsleep syz-fuzzer 98421 162190 22429 0 3 0x4000082 wait syz-fuzzer 98421 345114 22429 0 3 0x4000082 thrsleep syz-fuzzer 98421 115336 22429 0 3 0x4000082 kqread syz-fuzzer 98421 13076 22429 0 3 0x4000082 wait syz-fuzzer 98421 353888 22429 0 3 0x4000082 wait syz-fuzzer 98421 407037 22429 0 3 0x4000082 wait syz-fuzzer 98421 175870 22429 0 3 0x4000082 wait syz-fuzzer 98421 463822 22429 0 3 0x4000082 wait syz-fuzzer 22429 201666 67577 0 3 0x10008a sigsusp ksh 67577 133570 81266 0 3 0x9a kqread sshd 81266 141856 1 0 3 0x88 kqread sshd 18788 31317 22498 73 3 0x1100090 kqread syslogd 22498 481680 1 0 3 0x100082 netio syslogd 25793 59523 1 0 3 0x100080 kqread resolvd 74979 276092 97821 77 3 0x100092 kqread dhcpleased 73917 119490 97821 77 3 0x100092 kqread dhcpleased 97821 79982 1 0 3 0x80 kqread dhcpleased 55902 246648 0 0 2 0x14200 smr 34107 29897 0 0 2 0x14200 zerothread 19930 107067 0 0 3 0x14200 aiodoned aiodoned 27559 502641 0 0 3 0x14200 syncer update 228 104011 0 0 3 0x14200 cleaner cleaner 58772 501586 0 0 3 0x14200 reaper reaper 21864 445932 0 0 3 0x14200 pgdaemon pagedaemon 70762 181192 0 0 3 0x14200 bored viomb 68965 65748 0 0 3 0x40014200 acpi0 acpi0 97265 345372 0 0 3 0x14200 bored softnet 47325 61526 0 0 3 0x14200 bored softnet 27364 111778 0 0 3 0x14200 bored softnet 2989 43107 0 0 3 0x14200 bored softnet 90826 373911 0 0 2 0x14200 systqmp 28169 449071 0 0 3 0x14200 bored systq *63066 219131 0 0 7 0x40014200 softclock 42371 337682 0 0 3 0x40014200 idle0 1 229499 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 10221 6437K 7277K 78643K 32704 0 pcb 13 22K 26K 78643K 5422 0 rtable 170 15K 18K 78643K 4588 0 ifaddr 113 30K 34K 78643K 1819 0 sysctl 3 1K 1K 78643K 3 0 counters 25 17K 17K 78643K 732 0 ioctlops 0 0K 4K 78643K 3789 0 iov 0 0K 28K 78643K 3758 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1651 103K 104K 78643K 14558 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 170 0 VM map 2 0K 0K 78643K 2 0 sem 16 16K 32K 78643K 198 0 dirhash 9 1K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 16 57K 77K 78643K 16549 0 sigio 1 0K 0K 78643K 495 0 proc 61 59K 83K 78643K 3833 0 subproc 104 6K 6K 78643K 1352 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 1K 78643K 22315 0 in_multi 56 3K 6K 78643K 3060 0 ether_multi 1 0K 0K 78643K 481 0 mrt 1 0K 0K 78643K 46 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 259 1155K 1155K 78643K 259 0 exec 0 0K 1K 78643K 6938 0 pfkey data 0 0K 0K 78643K 3 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 331 90K 106K 78643K 108293 0 UVM aobj 131 4K 4K 78643K 134 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 663 0 NDP 12 0K 1K 78643K 630 0 temp 128 4686K 70222K 78643K 226983 0 kqueue 12 18K 28K 78643K 1729 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 1519 0 1516 17 16 1 3 0 8 0 rtentry 112 1462 0 1397 4 1 3 4 0 8 0 unpcb 144 16348 0 16331 166 164 2 10 0 8 1 syncache 296 111 0 111 28 28 0 1 0 8 0 tcpqe 32 210 32814 210 13 13 0 1 0 8 0 tcpcb 776 4956 0 4949 191 186 5 11 0 8 4 arp 88 218 0 205 1 0 1 1 0 8 0 ipq 40 54 0 54 10 10 0 1 0 8 0 ipqe 40 169 0 169 10 10 0 1 0 8 0 inpcb 336 35914 0 35903 386 382 4 23 0 8 2 nd6 48 349 0 334 1 0 1 1 0 8 0 pkpcb 40 27 0 27 7 7 0 1 0 8 0 kcovpl 48 104 0 96 1 0 1 1 0 8 0 mppekey 1024 42 0 42 3 3 0 1 0 8 0 ppxss 1160 453 0 453 38 38 0 1 0 8 0 pppxif 1352 143 0 143 23 23 0 1 0 8 0 pfstscr 40 205 0 178 1 0 1 1 0 8 0 pfosfp 40 4 0 2 1 0 1 1 0 8 0 pfosfpen 112 4 0 2 1 0 1 1 0 8 0 pfanchor 1280 850 184 338 49 6 43 43 0 8 0 pfqueue 264 4 0 4 1 1 0 1 0 8 0 pfstitem 24 266 0 182 1 0 1 1 0 8 0 pfstkey 128 511 0 457 5 3 2 2 0 8 0 pfstate 352 259 0 214 9 4 5 5 0 8 0 rttmr 136 5 0 5 2 2 0 1 0 8 0 art_heap8 4096 5 0 4 5 4 1 2 0 8 0 art_heap4 256 6913 0 6646 79 57 22 30 0 8 0 art_table 32 6918 0 6650 5 1 4 4 0 8 0 art_node 16 1455 0 1401 1 0 1 1 0 8 0 sysvmsgpl 40 12 0 8 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 179 0 165 1 0 1 1 0 8 0 shmpl 112 131 0 3 4 0 4 4 0 8 0 dirhash 1024 17 0 10 3 1 2 3 0 8 0 dino2pl 256 24763 0 23267 94 0 94 94 0 8 0 ffsino 240 24763 0 23267 89 0 89 89 0 8 0 nchpl 144 46984 0 45354 63 1 62 63 0 8 0 rtmask 32 18 0 18 6 6 0 1 0 8 0 uvmvnodes 80 6821 0 0 140 0 140 140 0 8 0 vnodes 216 6821 0 0 379 0 379 379 0 8 0 namei 1024 186584 0 186584 15 14 1 2 0 8 1 vmpool 664 65 0 65 9 9 0 1 0 8 0 kstatmem 264 776 0 752 4 1 3 3 0 8 0 scsiplug 72 21 0 21 7 7 0 1 0 8 0 scxspl 216 141349 0 141349 42 41 1 8 0 8 1 plimitpl 152 3268 0 3253 1 0 1 1 0 8 0 sigapl 424 16765 0 16699 10 2 8 8 0 8 0 futexpl 64 186255 0 186249 7 6 1 1 0 8 0 knotepl 120 318332 0 318254 141 134 7 15 0 8 2 kqueuepl 184 3785 0 3776 45 44 1 4 0 8 0 pipepl 288 9284 0 9257 150 147 3 12 0 8 0 fdescpl 432 16624 0 16597 4 0 4 4 0 8 0 filepl 120 160528 0 160257 263 253 10 20 0 8 1 lockfpl 104 5140 0 5138 15 14 1 3 0 8 0 lockfspl 48 1291 0 1289 2 1 1 2 0 8 0 sessionpl 144 120 0 104 1 0 1 1 0 8 0 pgrppl 48 272 0 256 1 0 1 1 0 8 0 ucredpl 104 19694 0 19681 1 0 1 1 0 8 0 zombiepl 144 16701 0 16699 5 4 1 1 0 8 0 processpl 1008 16765 0 16699 13 4 9 9 0 8 0 procpl 672 43392 0 43304 33 25 8 9 0 8 0 sosppl 168 170 0 169 27 26 1 1 0 8 0 sockpl 456 53888 0 53855 1173 1164 9 38 0 8 4 mcl64k 65536 648 0 648 41 40 1 1 0 8 1 mcl16k 16384 255 0 255 41 41 0 1 0 8 0 mcl12k 12288 720 0 720 39 38 1 1 0 8 1 mcl9k 9216 191 0 191 42 42 0 1 0 8 0 mcl8k 8192 2246 0 2246 34 34 0 1 0 8 0 mcl4k 4096 2225 0 2225 26 25 1 1 0 8 1 mcl2k2 2112 112 0 112 49 49 0 1 0 8 0 mcl2k 2048 112364 0 112272 73 60 13 32 0 8 0 mtagpl 96 1602 0 1492 23 18 5 7 0 8 0 mbufpl 256 540421 0 540023 1030 990 40 94 0 8 6 bufpl 288 34204 0 27377 488 0 488 488 0 8 0 anonpl 24 3258343 0 3237245 361 233 128 178 0 188 0 amapchunkpl 152 324671 0 323942 178 148 30 57 0 158 0 amappl16 200 31463 0 30623 187 142 45 45 0 8 0 amappl15 192 8 0 6 1 0 1 1 0 8 0 amappl14 184 526 0 514 2 1 1 2 0 8 0 amappl13 176 7 0 6 1 0 1 1 0 8 0 amappl12 168 1561 0 1558 1 0 1 1 0 8 0 amappl11 160 43 0 33 1 0 1 1 0 8 0 amappl10 152 192 0 183 1 0 1 1 0 8 0 amappl9 144 1009 0 1007 1 0 1 1 0 8 0 amappl8 136 609 0 534 3 0 3 3 0 8 0 amappl7 128 390 0 365 2 0 2 2 0 8 0 amappl6 120 688 0 679 1 0 1 1 0 8 0 amappl5 112 766 0 760 1 0 1 1 0 8 0 amappl4 104 1629 0 1598 2 1 1 2 0 8 0 amappl3 96 47567 0 47513 2 0 2 2 0 8 0 amappl2 88 18167 0 18095 3 1 2 3 0 8 0 amappl1 80 373857 0 373148 23 6 17 22 0 8 0 amappl 88 106641 0 106459 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 72 133 0 3 3 0 3 3 0 8 0 uaddrrnd 24 16689 0 16662 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 16689 0 16662 1 0 1 1 0 8 0 vmmpekpl 168 150923 0 150871 3 0 3 3 0 8 0 vmmpepl 168 1542818 0 1539848 503 364 139 157 0 357 2 vmsppl 272 16688 0 16662 5 3 2 3 0 8 0 rwobjpl 24 398274 0 389368 60 6 54 54 0 8 0 pdppl 4096 33384 0 33324 1107 1043 64 70 0 8 4 pvpl 32 6436248 0 6409508 682 464 218 315 0 265 1 pmappl 216 16688 0 16662 2 0 2 2 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 3672 0 2846 25 0 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(ffffffff825814d2) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff825f66a4,ffffffff8261512d,308,ffffffff82551571) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd8069f675c0) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff829bfca8) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff829bfca8) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000fffff500) 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(ffffffff825814d2) at panic+0x161 sys/kern/subr_prf.c:198 __assert(ffffffff825f66a4,ffffffff8261512d,308,ffffffff82551571) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd8069f675c0) at arptfree+0x12d sys/netinet/if_ether.c:776 arptimer(ffffffff829bfca8) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff829bfca8) at timeout_run+0x8b sys/kern/kern_timeout.c:641 softclock_thread(ffff8000fffff500) at softclock_thread+0xf4 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7