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
 360252  39583      0           0          0    0  syz-executor
*457555  25559      0           0  0x4000000    1K syz-executor
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff8345283d) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348ecd5,ffffffff8349d59b,17b,ffffffff834a7855) at __assert+0x29 sys/kern/subr_prf.c:-1
bpfopen(11700,21,2000,ffff8000313b22b8) at bpfopen+0x2bd bpfilter_lookup sys/net/bpf.c:1832 [inline]
bpfopen(11700,21,2000,ffff8000313b22b8) at bpfopen+0x2bd sys/net/bpf.c:379
spec_open_clone(ffff80002f3a5098) at spec_open_clone+0x277 sys/kern/spec_vnops.c:722
spec_open(ffff80002f3a5098) at spec_open+0x319 sys/kern/spec_vnops.c:148
VOP_OPEN(fffffd8063f5f3a0,21,fffffd80097fd888,ffff8000313b22b8) at VOP_OPEN+0x8b sys/kern/vfs_vops.c:138
vn_open(ffff80002f3a52e8,21,0) at vn_open+0x7a5 sys/kern/vfs_vnops.c:183
doopenat(ffff8000313b22b8,ffffff9c,200000000000,20,0,0,b0977e50ad2f6f1b) at doopenat+0x35b sys/kern/vfs_syscalls.c:1155
sys_open(ffff8000313b22b8,ffff80002f3a55a0,ffff80002f3a54f0) at sys_open+0x59 sys/kern/vfs_syscalls.c:1063
syscall(ffff80002f3a55a0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002f3a55a0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x54794fc5af0, 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(ffffffff8345283d) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348ecd5,ffffffff8349d59b,17b,ffffffff834a7855) at __assert+0x29 sys/kern/subr_prf.c:-1
bpfopen(11700,21,2000,ffff8000313b22b8) at bpfopen+0x2bd bpfilter_lookup sys/net/bpf.c:1832 [inline]
bpfopen(11700,21,2000,ffff8000313b22b8) at bpfopen+0x2bd sys/net/bpf.c:379
spec_open_clone(ffff80002f3a5098) at spec_open_clone+0x277 sys/kern/spec_vnops.c:722
spec_open(ffff80002f3a5098) at spec_open+0x319 sys/kern/spec_vnops.c:148
VOP_OPEN(fffffd8063f5f3a0,21,fffffd80097fd888,ffff8000313b22b8) at VOP_OPEN+0x8b sys/kern/vfs_vops.c:138
vn_open(ffff80002f3a52e8,21,0) at vn_open+0x7a5 sys/kern/vfs_vnops.c:183
doopenat(ffff8000313b22b8,ffffff9c,200000000000,20,0,0,b0977e50ad2f6f1b) at doopenat+0x35b sys/kern/vfs_syscalls.c:1155
sys_open(ffff8000313b22b8,ffff80002f3a55a0,ffff80002f3a54f0) at sys_open+0x59 sys/kern/vfs_syscalls.c:1063
syscall(ffff80002f3a55a0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002f3a55a0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x54794fc5af0, count: -12
ddb{1}>