assert "rt->rt_ifa->ifa_ifp != NULL" failed: file "/syzkalplaenri/cm:a kneagrnerels /mduilagtincoorstei/ck earnseselr/ti

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: f6e3733c Introduce SC_DEBUG_SENSE() and simplify code by e..
git tree: openbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=11c0c013600000
kernel config: https://syzkaller.appspot.com/x/.config?x=26ca0a9c07f16a3a
dashboard link: https://syzkaller.appspot.com/bug?extid=9c8f4e3de2de0367c9d1

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+9c8f4e...@syzkaller.appspotmail.com

panic: kernel diagnostic assertion "rt->rt_ifa->ifa_ifp != NULL" failed:
file "/syzkalplaenri/cm:a kneagrnerels /mduilagtincoorstei/ck
earnseselr/tisoysn /n"!e_tk/eroruntele_.clo"c, k_lihneled ()" failed:
file "/syzkaller/managers/multicore/kernel/sys/kern/kern_fork.c", line 690
Stopped at db_enter+0x18: addq $0x8,%rsp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
426959 66647 0 0 0x4000000 0 syz-executor.0
*320235 95044 0 0 0x4000000 1 syz-executor.1
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic() at panic+0x15c sys/kern/subr_prf.c:207
__assert(ffffffff82247364,ffffffff82234246,2b2,ffffffff822153d4) at
__assert+0x2b sys/kern/subr_prf.c:154
proc_trampoline_mp() at proc_trampoline_mp+0x123
end trace frame: 0x0, count: 11
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{1}>
ddb{1}> set $lines = 0
ddb{1}> set $maxwidth = 0
ddb{1}> show panic
kernel diagnostic assertion "rt->rt_ifa->ifa_ifp != NULL" failed:
file "/syzkaller/managers/multicore/kernel/sys/net/route.c", line 848
ddb{1}> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic() at panic+0x15c sys/kern/subr_prf.c:207
__assert(ffffffff82247364,ffffffff82234246,2b2,ffffffff822153d4) at
__assert+0x2b sys/kern/subr_prf.c:154
proc_trampoline_mp() at proc_trampoline_mp+0x123
end trace frame: 0x0, count: -4
ddb{1}> show registers
rdi 0
rsi 0x1
rbp 0xffff80002156d340
rbx 0xffff80002156d3f0
rdx 0xffff800020ab0018
rcx 0
rax 0
r8 0xffffffff8207ddaf kprintf+0x16f
r9 0x1
r10 0x25
r11 0x657fe7b2bb2d737a
r12 0x3000000008
r13 0xffff80002156d350
r14 0x104
r15 0x1
rip 0xffffffff813dc988 db_enter+0x18
cs 0x8
rflags 0x246
rsp 0xffff80002156d330
ss 0
db_enter+0x18: addq $0x8,%rsp
ddb{1}> show proc
PROC (syz-executor.1) pid=320235 stat=onproc
flags process=0 proc=4000000<THREAD>
pri=57, usrpri=57, nice=20
forw=0xffffffffffffffff, list=0xffff800020ab0ee8,0xffff800020ab0c80
process=0xffff800020a8ae10 user=0xffff800021568000,
vmspace=0xfffffd807f00a000
estcpu=7, cpticks=1, pctcpu=0.0
user=0, sys=1, intr=0
ddb{1}> ps
PID TID PPID UID S FLAGS WAIT COMMAND
66647 323866 36554 0 2 0 syz-executor.0
66647 426959 36554 0 7 0x4000000 syz-executor.0
95044 184338 48088 0 2 0 syz-executor.1
95044 390391 48088 0 3 0x4000080 fsleep syz-executor.1
*95044 320235 48088 0 7 0x4000000 syz-executor.1
48088 459466 83374 0 3 0x82 nanosleep syz-executor.1
82958 355882 0 0 3 0x14200 acct acct
36554 23985 83374 0 2 0x482 syz-executor.0
58598 191999 0 0 3 0x14200 bored sosplice
83374 206765 96973 0 3 0x82 kqread syz-fuzzer
83374 47569 96973 0 3 0x4000082 thrsleep syz-fuzzer
83374 181557 96973 0 3 0x4000082 thrsleep syz-fuzzer
83374 84244 96973 0 3 0x4000082 thrsleep syz-fuzzer
83374 27763 96973 0 3 0x4000082 thrsleep syz-fuzzer
83374 234628 96973 0 3 0x4000082 thrsleep syz-fuzzer
83374 239657 96973 0 3 0x4000082 thrsleep syz-fuzzer
83374 12784 96973 0 3 0x4000082 thrsleep syz-fuzzer
83374 229702 96973 0 3 0x4000082 thrsleep syz-fuzzer
83374 124423 96973 0 3 0x4000082 thrsleep syz-fuzzer
96973 179848 84832 0 3 0x10008a pause ksh
84832 57289 75237 0 3 0x92 select sshd
10204 271189 1 0 3 0x100083 ttyin getty
75237 485749 1 0 3 0x80 select sshd
89486 152128 69372 74 3 0x100092 bpf pflogd
69372 266006 1 0 3 0x80 netio pflogd
62076 174005 23405 73 3 0x100090 kqread syslogd
23405 387799 1 0 3 0x100082 netio syslogd
36148 514629 1 77 3 0x100090 poll dhclient
19463 514414 1 0 3 0x80 poll dhclient
7097 302844 0 0 2 0x14200 zerothread
19772 331499 0 0 3 0x14200 aiodoned aiodoned
86368 213270 0 0 3 0x14200 syncer update
60324 389405 0 0 3 0x14200 cleaner cleaner
73714 171946 0 0 3 0x14200 reaper reaper
72764 426024 0 0 3 0x14200 pgdaemon pagedaemon
44681 79611 0 0 3 0x14200 bored crynlk
83787 394108 0 0 3 0x14200 bored crypto
57919 19049 0 0 3 0x40014200 acpi0 acpi0
84425 345282 0 0 3 0x40014200 idle1
61148 307265 0 0 3 0x14200 bored softnet
58953 399498 0 0 3 0x14200 bored systqmp
51914 457961 0 0 3 0x14200 bored systq
70415 61476 0 0 2 0x40014200 softclock
67834 31375 0 0 3 0x40014200 idle0
72357 203667 0 0 3 0x14200 bored smr
1 154972 0 0 3 0x82 wait init
0 0 -1 0 3 0x10200 scheduler swapper
ddb{1}> show all locks
Process 66647 (syz-executor.0) thread 0xffff800020ab0c70 (426959)
exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82676880)
#0 witness_lock+0x52e sys/kern/subr_witness.c:1163
#1 rt_clone+0x5c sys/net/route.c:266
#2 rtalloc_mpath+0xba rt_match sys/net/route.c:244 [inline]
#2 rtalloc_mpath+0xba sys/net/route.c:359
#3 ip_output+0x4f2 sys/netinet/ip_output.c:204
#4 rip_output+0x252 sys/netinet/raw_ip.c:289
#5 rip_usrreq+0x46a sys/netinet/raw_ip.c:538
#6 sosend+0x645 sys/kern/uipc_socket.c:524
#7 sendit+0x52b sys/kern/uipc_syscalls.c:662
#8 sys_sendto+0x80 sys/kern/uipc_syscalls.c:527
#9 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline]
#9 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555
#10 Xsyscall+0x128
exclusive rwlock netlock r = 0 (0xffffffff824ee388)
#0 witness_lock+0x52e sys/kern/subr_witness.c:1163
#1 solock+0x5a sys/kern/uipc_socket2.c:282
#2 sosend+0x51b sys/kern/uipc_socket.c:512
#3 sendit+0x52b sys/kern/uipc_syscalls.c:662
#4 sys_sendto+0x80 sys/kern/uipc_syscalls.c:527
#5 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline]
#5 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555
#6 Xsyscall+0x128
ddb{1}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim
devbuf 9575 6568K 7981K 78643K 16955 0 0
pcb 13 8K 8K 78643K 203 0 0
rtable 117 5K 6K 78643K 908 0 0
ifaddr 81 17K 18K 78643K 286 0 0
counters 39 33K 33K 78643K 39 0 0
ioctlops 0 0K 4K 78643K 1501 0 0
iov 0 0K 32K 78643K 191 0 0
mount 1 1K 1K 78643K 1 0 0
vnodes 1226 77K 77K 78643K 2951 0 0
UFS quota 1 32K 32K 78643K 1 0 0
UFS mount 5 36K 36K 78643K 5 0 0
shm 2 1K 5K 78643K 15 0 0
VM map 2 1K 1K 78643K 8 0 0
sem 12 0K 0K 78643K 368 0 0
dirhash 12 2K 2K 78643K 12 0 0
ACPI 1808 196K 290K 78643K 12765 0 0
file desc 6 17K 25K 78643K 1060 0 0
sigio 0 0K 0K 78643K 8 0 0
proc 62 63K 95K 78643K 704 0 0
subproc 32 2K 2K 78643K 119 0 0
NFS srvsock 1 0K 0K 78643K 1 0 0
NFS daemon 1 16K 16K 78643K 1 0 0
ip_moptions 0 0K 0K 78643K 555 0 0
in_multi 30 2K 2K 78643K 120 0 0
ether_multi 1 0K 0K 78643K 7 0 0
mrt 0 0K 0K 78643K 5 0 0
ISOFS mount 1 32K 32K 78643K 1 0 0
MSDOSFS mount 1 16K 16K 78643K 1 0 0
ttys 66 291K 291K 78643K 66 0 0
exec 0 0K 1K 78643K 397 0 0
pagedep 1 8K 8K 78643K 1 0 0
inodedep 1 32K 32K 78643K 1 0 0
newblk 1 0K 0K 78643K 1 0 0
VM swap 7 26K 26K 78643K 7 0 0
UVM amap 115 22K 24K 78643K 4523 0 0
UVM aobj 33 4K 4K 78643K 35 0 0
memdesc 1 4K 4K 78643K 1 0 0
crypto data 1 1K 1K 78643K 1 0 0
ip6_options 0 0K 0K 78643K 262 0 0
NDP 20 0K 0K 78643K 85 0 0
temp 216 3560K 3634K 78643K 58022 0 0
kqueue 0 0K 0K 78643K 6 0 0
SYN cache 2 16K 16K 78643K 2 0 0
ddb{1}> show all pools
Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg
Idle
arp 64 29 0 23 1 0 1 1 0
8 0
plcache 128 20 0 0 1 0 1 1 0
8 0
rtpcb 80 84 0 81 1 0 1 1 0
8 0
rtentry 112 168 0 121 2 0 2 2 0
8 0
unpcb 120 480 0 469 1 0 1 1 0
8 0
syncache 264 8 0 8 3 3 0 1 0
8 0
tcpqe 32 6444 0 6444 2 2 0 1 0
8 0
tcpcb 544 867 0 861 3 2 1 2 0
8 0
inpcb 280 1599 0 1589 4 2 2 2 0
8 1
rttmr 72 2 0 2 2 1 1 1 0
8 1
nd6 48 33 0 28 1 0 1 1 0
8 0
pkpcb 40 8 0 8 3 3 0 1 0
8 0
ppxss 1128 34 0 34 3 2 1 1 0
8 1
pffrag 232 13 0 13 5 5 0 1 0
482 0
pffrnode 88 13 0 13 5 5 0 1 0
8 0
pffrent 40 203 0 203 5 5 0 1 0
8 0
pfosfp 40 846 0 423 5 0 5 5 0
8 0
pfosfpen 112 1428 0 714 21 0 21 21 0
8 0
pfstitem 24 96 0 52 1 0 1 1 0
8 0
pfstkey 112 96 0 52 2 0 2 2 0
8 0
pfstate 328 96 0 52 6 0 6 6 0
8 0
pfrule 1360 21 0 16 2 1 1 2 0
8 0
art_heap8 4096 1 0 0 1 0 1 1 0
8 0
art_heap4 256 928 0 663 28 1 27 27 0
8 6
art_table 32 929 0 663 4 0 4 4 0
8 0
art_node 16 164 0 120 1 0 1 1 0
8 0
sysvmsgpl 40 40 0 30 1 0 1 1 0
8 0
semupl 112 2 0 2 1 1 0 1 0
8 0
semapl 112 366 0 356 1 0 1 1 0
8 0
shmpl 112 33 0 2 1 0 1 1 0
8 0
dirhash 1024 17 0 0 3 0 3 3 0
8 0
dino1pl 128 3014 0 1607 46 0 46 46 0
8 0
ffsino 272 3014 0 1607 95 0 95 95 0
8 0
nchpl 144 4926 0 3311 61 0 61 61 0
8 0
uvmvnodes 72 4526 0 0 83 0 83 83 0
8 0
vnodes 208 4526 0 0 239 0 239 239 0
8 0
namei 1024 16253 0 16253 2 1 1 1 0
8 1
percpumem 16 30 0 0 1 0 1 1 0
8 0
vmpool 552 6 0 6 3 3 0 1 0
8 0
scsiplug 64 1 0 1 1 1 0 1 0
8 0
scxspl 192 14222 0 14222 14 13 1 7 0
8 1
plimitpl 152 99 0 91 1 0 1 1 0
8 0
sigapl 432 1245 0 1229 3 1 2 3 0
8 0
futexpl 56 25125 0 25124 1 0 1 1 0
8 0
knotepl 112 299 0 280 1 0 1 1 0
8 0
kqueuepl 104 310 0 307 1 0 1 1 0
8 0
pipepl 112 836 0 813 4 3 1 2 0
8 0
fdescpl 488 1246 0 1229 3 0 3 3 0
8 0
filepl 152 10700 0 10591 13 8 5 7 0
8 0
lockfpl 104 379 0 378 1 0 1 1 0
8 0
lockfspl 48 136 0 135 1 0 1 1 0
8 0
sessionpl 112 23 0 12 1 0 1 1 0
8 0
pgrppl 48 38 0 27 1 0 1 1 0
8 0
ucredpl 96 1206 0 1197 1 0 1 1 0
8 0
zombiepl 144 1231 0 1231 3 2 1 1 0
8 1
processpl 896 1265 0 1231 4 0 4 4 0
8 0
procpl 632 3493 0 3447 6 1 5 5 0
8 1
srpgc 64 7 0 7 3 2 1 1 0
8 1
sosppl 128 23 0 23 4 4 0 1 0
8 0
sockpl 384 2185 0 2161 10 6 4 5 0
8 1
mcl64k 65536 19 0 0 3 1 2 3 0
8 0
mcl16k 16384 7 0 0 1 0 1 1 0
8 0
mcl12k 12288 8 0 0 1 0 1 1 0
8 0
mcl9k 9216 8 0 0 1 0 1 1 0
8 0
mcl8k 8192 5 0 0 1 0 1 1 0
8 0
mcl4k 4096 13 0 0 2 0 2 2 0
8 0
mcl2k2 2112 4 0 0 1 0 1 1 0
8 0
mcl2k 2048 167 0 0 19 0 19 19 0
8 0
mtagpl 80 420 0 0 9 0 9 9 0
8 0
mbufpl 256 1011 0 0 62 1 61 61 0
8 0
bufpl 256 9090 0 2042 441 0 441 441 0
8 0
anonpl 16 133088 0 120405 90 19 71 87 0
124 0
amapchunkpl 152 7922 0 7803 15 7 8 12 0
158 0
amappl16 192 5573 0 4605 70 21 49 61 0
8 0
amappl15 184 683 0 679 1 0 1 1 0
8 0
amappl14 176 56 0 55 2 1 1 1 0
8 0
amappl13 168 222 0 221 1 0 1 1 0
8 0
amappl12 160 7 0 5 2 1 1 1 0
8 0
amappl11 152 285 0 267 1 0 1 1 0
8 0
amappl10 144 52 0 48 1 0 1 1 0
8 0
amappl9 136 846 0 840 1 0 1 1 0
8 0
amappl8 128 388 0 360 1 0 1 1 0
8 0
amappl7 120 97 0 90 1 0 1 1 0
8 0
amappl6 112 299 0 282 1 0 1 1 0
8 0
amappl5 104 180 0 165 1 0 1 1 0
8 0
amappl4 96 1581 0 1552 1 0 1 1 0
8 0
amappl3 88 146 0 141 1 0 1 1 0
8 0
amappl2 80 9281 0 9196 3 1 2 3 0
8 0
amappl1 72 37425 0 36961 27 16 11 20 0
8 0
amappl 80 3831 0 3788 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 17 0 17 1 1 0 1 0
8 0
aobjpl 64 34 0 2 1 0 1 1 0
8 0
uaddrrnd 24 1252 0 1229 1 0 1 1 0
8 0
uaddrbest 32 2 0 0 1 0 1 1 0
8 0
uaddr 24 1252 0 1229 1 0 1 1 0
8 0
vmmpekpl 168 13643 0 13612 2 0 2 2 0
8 0
vmmpepl 168 161336 0 159116 206 77 129 134 0 357
32
vmsppl 368 1245 0 1229 2 0 2 2 0
8 0
pdppl 4096 2511 0 2470 7 1 6 6 0
8 0
pvpl 32 404690 0 388688 229 59 170 203 0
265 5
pmappl 232 1251 0 1235 4 3 1 2 0
8 0
extentpl 40 41 0 26 1 0 1 1 0
8 0
phpool 112 674 0 10 19 0 19 19 0
8 0


---
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[Anton Lindqvist]

#syz dup: assert "rt->rt_ifa->ifa_ifp != NULL" failed in route.c