panic: kernel diagnostic assertion "bpfilter_lookup(unit) == NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/net/bpf.c", line 379
Stopped at      db_enter+0x25:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*293654   5000      0           0  0x4000000    1K syz-executor
 182418  21585      0         0x2          0    0  syz-executor
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff83449919) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348ca56,ffffffff8349793e,17b,ffffffff834a1152) at __assert+0x29 sys/kern/subr_prf.c:-1
bpfopen(11700,101,2000,ffff800030faf4e8) at bpfopen+0x2bd bpfilter_lookup sys/net/bpf.c:1832 [inline]
bpfopen(11700,101,2000,ffff800030faf4e8) at bpfopen+0x2bd sys/net/bpf.c:379
spec_open_clone(ffff80003c3e1f78) at spec_open_clone+0x277 sys/kern/spec_vnops.c:722
spec_open(ffff80003c3e1f78) at spec_open+0x319 sys/kern/spec_vnops.c:148
VOP_OPEN(fffffd806a1922a8,101,fffffd80097fd750,ffff800030faf4e8) at VOP_OPEN+0x8b sys/kern/vfs_vops.c:138
vn_open(ffff80003c3e21b8,101,0) at vn_open+0x6a0 sys/kern/vfs_vnops.c:177
doopenat(ffff800030faf4e8,ffffff9c,200000000000,100,0,0,ab09581fe11b0eb7) at doopenat+0x35b sys/kern/vfs_syscalls.c:1155
sys_open(ffff800030faf4e8,ffff80003c3e2470,ffff80003c3e23c0) at sys_open+0x59 sys/kern/vfs_syscalls.c:1063
syscall(ffff80003c3e2470) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c3e2470) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x2d14073d020, count: 3
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
*cpu1: kernel diagnostic assertion "bpfilter_lookup(unit) == NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/net/bpf.c", line 379
ddb{1}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff83449919) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348ca56,ffffffff8349793e,17b,ffffffff834a1152) at __assert+0x29 sys/kern/subr_prf.c:-1
bpfopen(11700,101,2000,ffff800030faf4e8) at bpfopen+0x2bd bpfilter_lookup sys/net/bpf.c:1832 [inline]
bpfopen(11700,101,2000,ffff800030faf4e8) at bpfopen+0x2bd sys/net/bpf.c:379
spec_open_clone(ffff80003c3e1f78) at spec_open_clone+0x277 sys/kern/spec_vnops.c:722
spec_open(ffff80003c3e1f78) at spec_open+0x319 sys/kern/spec_vnops.c:148
VOP_OPEN(fffffd806a1922a8,101,fffffd80097fd750,ffff800030faf4e8) at VOP_OPEN+0x8b sys/kern/vfs_vops.c:138
vn_open(ffff80003c3e21b8,101,0) at vn_open+0x6a0 sys/kern/vfs_vnops.c:177
doopenat(ffff800030faf4e8,ffffff9c,200000000000,100,0,0,ab09581fe11b0eb7) at doopenat+0x35b sys/kern/vfs_syscalls.c:1155
sys_open(ffff800030faf4e8,ffff80003c3e2470,ffff80003c3e23c0) at sys_open+0x59 sys/kern/vfs_syscalls.c:1063
syscall(ffff80003c3e2470) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c3e2470) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x2d14073d020, count: -12
ddb{1}> show registers
rdi                                0
rsi                              0x1
rbp               0xffff80003c3e1d50
rbx               0xffff8000299bee07
rdx                                0
rcx               0xffff800030faf4e8
rax               0xffff8000299bdff0
r8                 0x101010101010101
r9                0x8080808080808080
r10               0xe34327fd0db5d02f
r11               0xd971742069efa3a1
r12               0xffff8000299bec08
r13                                0
r14                                0
r15                              0x1
rip               0xffffffff81ab4185    db_enter+0x25
cs                               0x8
rflags                         0x246
rsp               0xffff80003c3e1d40
ss                                 0
db_enter+0x25:  addq    $0x8,%rsp
ddb{1}>