panic: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/netinet/if_ether.c", line 776 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 480932 71160 0 0x2 0 1 syz-executor.2 *505205 84696 0 0x14000 0x40000200 0K softclock db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff827495dd) at panic+0x177 sys/kern/subr_prf.c:198 __assert(ffffffff827cae93,ffffffff827c4c5f,308,ffffffff827191e4) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd806b782160) at arptfree+0x12e sys/netinet/if_ether.c:776 arptimer(ffffffff82c382b0) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c382b0) at timeout_run+0xcc sys/kern/kern_timeout.c:641 softclock_thread(ffff800021179308) at softclock_thread+0x134 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{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic *cpu0: kernel diagnostic assertion "ifp != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/netinet/if_ether.c", line 776 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff827495dd) at panic+0x177 sys/kern/subr_prf.c:198 __assert(ffffffff827cae93,ffffffff827c4c5f,308,ffffffff827191e4) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd806b782160) at arptfree+0x12e sys/netinet/if_ether.c:776 arptimer(ffffffff82c382b0) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c382b0) at timeout_run+0xcc sys/kern/kern_timeout.c:641 softclock_thread(ffff800021179308) at softclock_thread+0x134 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff8000211856e0 rbx 0xffffffff82b8eb8f cpu_info_full_primary+0x2b8f rdx 0 rcx 0 rax 0xffff800021179308 r8 0x101010101010101 r9 0x8080808080808080 r10 0xc852c73d5ddaabdd r11 0xa3d078a5896330a2 r12 0xffffffff82b8e990 cpu_info_full_primary+0x2990 r13 0 r14 0 r15 0x1 rip 0xffffffff8229d9e8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000211856d0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (softclock) pid=505205 stat=onproc flags process=14000 proc=40000200 pri=0, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800021179878,0xffff800021178da8 process=0xffff8000ffffee10 user=0xffff800021180000, vmspace=0xffffffff82bfa0e8 estcpu=0, cpticks=1, pctcpu=0.1 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 58740 288064 71160 0 3 0x80 nanoslp syz-executor.2 58740 245985 71160 0 3 0x4000080 netio syz-executor.2 58740 321684 71160 0 3 0x4000080 fsleep syz-executor.2 43550 48105 6733 0 3 0x82 piperd syz-executor.1 77098 68446 6733 0 3 0x82 piperd syz-executor.7 78201 343867 6733 0 3 0x82 piperd syz-executor.4 75080 338710 6733 0 3 0x82 piperd syz-executor.6 38833 59718 1 0 3 0 vmmaplk syz-executor.0 38833 238653 1 0 3 0x4000000 vmmaplk syz-executor.0 71160 480932 6733 0 7 0x2 syz-executor.2 88400 491861 1 0 3 0x100083 ttyin getty 27619 273651 6733 0 3 0x82 piperd syz-executor.3 29594 476452 0 0 3 0x14280 nfsidl nfsio 28738 321949 0 0 3 0x14280 nfsidl nfsio 63536 141672 0 0 3 0x14280 nfsidl nfsio 9577 240138 0 0 3 0x14280 nfsidl nfsio 52298 361210 0 0 3 0x14280 nfsidl nfsio 332 47674 0 0 3 0x14280 nfsidl nfsio 97935 312837 0 0 3 0x14280 nfsidl nfsio 89191 341420 0 0 3 0x14280 nfsidl nfsio 25519 503723 0 0 3 0x14280 nfsidl nfsio 62815 10679 0 0 3 0x14280 nfsidl nfsio 3409 241192 0 0 3 0x14280 nfsidl nfsio 47182 30681 0 0 3 0x14280 nfsidl nfsio 56339 225702 0 0 3 0x14280 nfsidl nfsio 91068 158549 0 0 3 0x14280 nfsidl nfsio 85061 499618 0 0 3 0x14280 nfsidl nfsio 18228 378073 0 0 3 0x14280 nfsidl nfsio 33583 117268 0 0 3 0x14280 nfsidl nfsio 41461 452918 0 0 3 0x14280 nfsidl nfsio 97547 191306 0 0 3 0x14280 nfsidl nfsio 38132 415097 0 0 3 0x14280 nfsidl nfsio 84626 19491 0 0 3 0x14200 bored sosplice 6733 515924 48353 0 3 0x82 wait syz-fuzzer 6733 430392 48353 0 3 0x4000082 thrsleep syz-fuzzer 6733 509339 48353 0 3 0x4000082 kqread syz-fuzzer 6733 311833 48353 0 3 0x4000082 wait syz-fuzzer 6733 262750 48353 0 3 0x4000082 wait syz-fuzzer 6733 71868 48353 0 3 0x4000082 thrsleep syz-fuzzer 6733 438167 48353 0 3 0x4000082 thrsleep syz-fuzzer 6733 29362 48353 0 3 0x4000082 thrsleep syz-fuzzer 6733 361566 48353 0 3 0x4000082 thrsleep syz-fuzzer 6733 342372 48353 0 3 0x4000082 thrsleep syz-fuzzer 6733 42295 48353 0 3 0x4000082 wait syz-fuzzer 6733 517239 48353 0 3 0x4000082 thrsleep syz-fuzzer 6733 16745 48353 0 3 0x4000082 wait syz-fuzzer 6733 382324 48353 0 3 0x4000082 thrsleep syz-fuzzer 6733 385144 48353 0 3 0x4000082 wait syz-fuzzer 6733 377002 48353 0 3 0x4000082 thrsleep syz-fuzzer 48353 439947 49795 0 3 0x10008a sigsusp ksh 49795 171919 78919 0 3 0x9a kqread sshd 78919 36453 1 0 3 0x88 kqread sshd 28075 346579 73877 74 3 0x1100092 bpf pflogd 73877 437988 1 0 3 0x80 netio pflogd 49714 284566 33696 73 3 0x1100090 kqread syslogd 33696 356009 1 0 3 0x100082 netio syslogd 5119 104806 1 0 3 0x100080 kqread resolvd 65436 185542 17592 77 3 0x100092 kqread dhcpleased 86327 472024 17592 77 3 0x100092 kqread dhcpleased 17592 21030 1 0 3 0x80 kqread dhcpleased 32208 448392 0 0 3 0x14200 bored smr 97992 432462 0 0 3 0x14200 pgzero zerothread 4825 148889 0 0 3 0x14200 aiodoned aiodoned 52035 194579 0 0 3 0x14200 syncer update 21931 52324 0 0 3 0x14200 cleaner cleaner 55839 2826 0 0 3 0x14200 reaper reaper 71812 156402 0 0 3 0x14200 pgdaemon pagedaemon 84667 211004 0 0 3 0x14200 bored viomb 54209 228207 0 0 3 0x40014200 acpi0 acpi0 1946 159761 0 0 3 0x40014200 idle1 52371 510954 0 0 3 0x14200 bored softnet 76990 33970 0 0 3 0x14200 bored softnet 87971 397731 0 0 3 0x14200 bored softnet 37112 41925 0 0 3 0x14200 bored softnet 8195 516085 0 0 3 0x14200 bored systqmp 99252 319868 0 0 3 0x14200 bored systq *84696 505205 0 0 7 0x40014200 softclock 62871 376028 0 0 3 0x40014200 idle0 1 372265 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 10257 6513K 7161K 78643K 25504 0 pcb 13 16K 18K 78643K 1544 0 rtable 176 16K 19K 78643K 2057 0 ifaddr 80 26K 29K 78643K 803 0 sysctl 3 1K 1K 78643K 3 0 counters 54 35K 36K 78643K 488 0 ioctlops 0 0K 4K 78643K 2784 0 iov 0 0K 40K 78643K 5128 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1662 104K 104K 78643K 12294 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 102 0 VM map 2 1K 1K 78643K 2 0 sem 13 5K 8K 78643K 363 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 11 37K 89K 78643K 10042 0 sigio 0 0K 0K 78643K 298 0 proc 71 91K 140K 78643K 1933 0 subproc 104 6K 7K 78643K 559 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 2640 0 in_multi 63 4K 7K 78643K 735 0 ether_multi 1 0K 0K 78643K 50 0 mrt 1 0K 0K 78643K 26 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 301 1341K 1341K 78643K 301 0 exec 0 0K 1K 78643K 1689 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 385 93K 115K 78643K 72039 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 363 0 NDP 15 0K 1K 78643K 272 0 temp 143 5774K 6799K 78643K 112853 0 kqueue 12 18K 32K 78643K 767 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 plcache 128 22 0 0 1 0 1 1 0 8 0 rtpcb 120 723 0 720 9 8 1 3 0 8 0 rtentry 112 687 0 620 5 2 3 4 0 8 0 unpcb 144 7542 0 7524 86 82 4 10 0 8 3 syncache 296 36 0 36 9 9 0 1 0 8 0 tcpqe 32 96 0 96 6 6 0 1 0 8 0 tcpcb 776 10172 0 10168 140 132 8 14 0 8 7 arp 120 97 0 84 1 0 1 1 0 8 0 inpcb 368 17005 0 16998 190 183 7 17 0 8 6 nd6 48 151 0 135 1 0 1 1 0 8 0 pkpcb 40 145 0 145 3 3 0 1 0 8 0 kcovpl 48 43 0 35 1 0 1 1 0 8 0 ppxss 1256 124 0 124 15 15 0 1 0 8 0 pppxif 1456 43 0 43 12 12 0 1 0 8 0 pfstscr 40 64 0 64 8 8 0 1 0 8 0 pffrag 232 32 0 32 3 3 0 1 0 482 0 pffrnode 88 31 0 31 3 3 0 1 0 8 0 pffrent 40 81 0 81 3 3 0 1 0 8 0 pfosfp 40 1428 0 1005 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfanchor 1280 768 9 256 50 7 43 43 0 8 0 pfqueue 264 4 0 4 2 2 0 1 0 8 0 pfstitem 24 396 0 346 1 0 1 1 0 8 0 pfstkey 128 511 0 461 3 1 2 2 0 8 0 pfstate 384 452 0 402 10 4 6 6 0 8 0 pfrule 1344 21 0 16 2 1 1 2 0 8 0 rttmr 136 11 0 11 4 4 0 1 0 8 0 art_heap8 4096 5 0 4 5 4 1 2 0 8 0 art_heap4 256 3084 0 2793 48 22 26 32 0 8 0 art_table 32 3089 0 2797 6 2 4 5 0 8 0 art_node 16 680 0 622 1 0 1 1 0 8 0 sysvmsgpl 40 63 0 52 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 357 0 346 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 14983 0 13516 93 0 93 93 0 8 0 ffsino 272 14983 0 13516 99 0 99 99 0 8 0 nchpl 144 28421 0 26789 63 0 63 63 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 108171 0 108171 8 7 1 2 0 8 1 percpumem 16 257 0 217 1 0 1 1 0 8 0 vmpool 696 95 0 95 8 7 1 1 0 8 1 kstatmem 264 342 0 312 10 7 3 3 0 8 0 scsiplug 72 9 0 9 3 3 0 1 0 8 0 scxspl 216 77677 0 77677 34 33 1 8 0 8 1 plimitpl 152 1160 0 1144 1 0 1 1 0 8 0 sigapl 424 10334 0 10272 9 1 8 8 0 8 0 futexpl 64 89490 0 89489 7 6 1 1 0 8 0 knotepl 120 647 0 0 14 0 14 14 0 8 0 kqueuepl 216 1973 0 1965 32 31 1 8 0 8 0 pipepl 320 2022 0 1999 61 58 3 8 0 8 0 fdescpl 496 10274 0 10250 6 1 5 5 0 8 1 filepl 152 81131 0 80834 127 114 13 23 0 8 0 lockfpl 104 3253 0 3251 8 6 2 2 0 8 1 lockfspl 48 779 0 777 1 0 1 1 0 8 0 sessionpl 144 60 0 43 1 0 1 1 0 8 0 pgrppl 48 178 0 161 1 0 1 1 0 8 0 ucredpl 104 10784 0 10771 1 0 1 1 0 8 0 zombiepl 144 10273 0 10272 4 3 1 1 0 8 0 processpl 1072 10334 0 10272 5 0 5 5 0 8 0 procpl 696 29511 0 29431 27 17 10 11 0 8 0 srpgc 96 46 0 46 14 14 0 1 0 8 0 sosppl 168 130 0 130 17 16 1 1 0 8 1 sockpl 488 25501 0 25473 478 466 12 37 0 8 8 mcl64k 65536 19 0 0 3 0 3 3 0 8 0 mcl16k 16384 23 0 0 3 1 2 3 0 8 0 mcl12k 12288 24 0 0 2 0 2 2 0 8 0 mcl9k 9216 17 0 0 2 0 2 2 0 8 0 mcl8k 8192 18 0 0 3 0 3 3 0 8 0 mcl4k 4096 27 0 0 4 1 3 3 0 8 0 mcl2k2 2112 13 0 0 1 0 1 1 0 8 0 mcl2k 2048 598 0 0 72 18 54 72 0 8 0 mtagpl 96 590 0 0 11 0 11 11 0 8 0 mbufpl 256 3840 0 0 231 0 231 231 0 8 0 bufpl 288 19179 0 12857 452 0 452 452 0 8 0 anonpl 24 2054594 0 2039006 182 28 154 154 0 186 0 amapchunkpl 152 201299 0 200516 61 21 40 52 0 158 0 amappl16 200 18456 0 17954 99 70 29 41 0 8 0 amappl15 192 61 0 59 1 0 1 1 0 8 0 amappl14 184 263 0 248 2 1 1 2 0 8 0 amappl13 176 16 0 14 1 0 1 1 0 8 0 amappl12 168 876 0 872 1 0 1 1 0 8 0 amappl11 160 50 0 36 1 0 1 1 0 8 0 amappl10 152 79 0 65 1 0 1 1 0 8 0 amappl9 144 1012 0 1012 15 15 0 1 0 8 0 amappl8 136 527 0 408 5 0 5 5 0 8 0 amappl7 128 253 0 226 2 0 2 2 0 8 0 amappl6 120 406 0 383 1 0 1 1 0 8 0 amappl5 112 435 0 423 1 0 1 1 0 8 0 amappl4 104 945 0 907 4 2 2 2 0 8 0 amappl3 96 30840 0 30791 2 0 2 2 0 8 0 amappl2 88 11155 0 11079 3 1 2 3 0 8 0 amappl1 80 236384 0 235591 28 8 20 23 0 8 0 amappl 88 70767 0 70564 9 1 8 8 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 10369 0 10345 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 10369 0 10345 1 0 1 1 0 8 0 vmmpekpl 168 85307 0 85245 5 1 4 4 0 8 0 vmmpepl 168 956670 0 953943 331 182 149 161 0 357 0 vmsppl 368 10368 0 10345 4 1 3 4 0 8 0 rwobjpl 56 256148 0 248264 132 17 115 117 0 8 0 pdppl 4096 20745 0 20690 559 488 71 81 0 8 16 pvpl 32 3961829 0 3940988 375 122 253 255 0 265 0 pmappl 248 10368 0 10345 3 1 2 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1795 0 742 31 0 31 31 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff827495dd) at panic+0x177 sys/kern/subr_prf.c:198 __assert(ffffffff827cae93,ffffffff827c4c5f,308,ffffffff827191e4) at __assert+0x25 sys/kern/subr_prf.c:157 arptfree(fffffd806b782160) at arptfree+0x12e sys/netinet/if_ether.c:776 arptimer(ffffffff82c382b0) at arptimer+0x88 sys/netinet/if_ether.c:135 timeout_run(ffffffff82c382b0) at timeout_run+0xcc sys/kern/kern_timeout.c:641 softclock_thread(ffff800021179308) at softclock_thread+0x134 sys/kern/kern_timeout.c:765 end trace frame: 0x0, count: -7 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffff800020d68ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 __mp_lock(ffffffff82dc73e0) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82dc73e0) at __mp_lock+0x122 sys/kern/kern_lock.c:147 syscall(ffff80002e3f9330) at syscall+0x53d mi_syscall sys/sys/syscall_mi.h:112 [inline] syscall(ffff80002e3f9330) at syscall+0x53d sys/arch/amd64/amd64/trap.c:626 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffffb7c0, count: 9 ddb{1}> trace x86_ipi_db(ffff800020d68ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 __mp_lock(ffffffff82dc73e0) at __mp_lock+0x122 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff82dc73e0) at __mp_lock+0x122 sys/kern/kern_lock.c:147 syscall(ffff80002e3f9330) at syscall+0x53d mi_syscall sys/sys/syscall_mi.h:112 [inline] syscall(ffff80002e3f9330) at syscall+0x53d sys/arch/amd64/amd64/trap.c:626 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffffb7c0, count: -6