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
*505911   3723      0           0  0x4000000    0K syz-executor
 425107  13408      0  0x10000002          0    1  syz-executor
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff8344fb66) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348ca6c,ffffffff8349ec53,17b,ffffffff834a8e25) at __assert+0x29 sys/kern/subr_prf.c:-1
bpfopen(11700,bf,2000,ffff80003abd8d18) at bpfopen+0x2bd bpfilter_lookup sys/net/bpf.c:1832 [inline]
bpfopen(11700,bf,2000,ffff80003abd8d18) at bpfopen+0x2bd sys/net/bpf.c:379
spec_open_clone(ffff80003a3bd9a8) at spec_open_clone+0x277 sys/kern/spec_vnops.c:722
spec_open(ffff80003a3bd9a8) at spec_open+0x319 sys/kern/spec_vnops.c:148
VOP_OPEN(fffffd805f382cb0,bf,fffffd80097fd618,ffff80003abd8d18) at VOP_OPEN+0x8b sys/kern/vfs_vops.c:138
vn_open(ffff80003a3bdbf8,bf,0) at vn_open+0x7a5 sys/kern/vfs_vnops.c:183
doopenat(ffff80003abd8d18,ffffff9c,200000000100,be,0,0,f544708f1e74beaf) at doopenat+0x35b sys/kern/vfs_syscalls.c:1155
sys_openat(ffff80003abd8d18,ffff80003a3bdeb0,ffff80003a3bde00) at sys_openat+0x58 sys/kern/vfs_syscalls.c:1094
syscall(ffff80003a3bdeb0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003a3bdeb0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x6c57f48d370, count: 3
https://www.openbsd.org/ddb.html describes the minimum info required in bug
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ddb{0}> 
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
*cpu0: kernel diagnostic assertion "bpfilter_lookup(unit) == NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/net/bpf.c", line 379
ddb{0}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff8344fb66) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8348ca6c,ffffffff8349ec53,17b,ffffffff834a8e25) at __assert+0x29 sys/kern/subr_prf.c:-1
bpfopen(11700,bf,2000,ffff80003abd8d18) at bpfopen+0x2bd bpfilter_lookup sys/net/bpf.c:1832 [inline]
bpfopen(11700,bf,2000,ffff80003abd8d18) at bpfopen+0x2bd sys/net/bpf.c:379
spec_open_clone(ffff80003a3bd9a8) at spec_open_clone+0x277 sys/kern/spec_vnops.c:722
spec_open(ffff80003a3bd9a8) at spec_open+0x319 sys/kern/spec_vnops.c:148
VOP_OPEN(fffffd805f382cb0,bf,fffffd80097fd618,ffff80003abd8d18) at VOP_OPEN+0x8b sys/kern/vfs_vops.c:138
vn_open(ffff80003a3bdbf8,bf,0) at vn_open+0x7a5 sys/kern/vfs_vnops.c:183
doopenat(ffff80003abd8d18,ffffff9c,200000000100,be,0,0,f544708f1e74beaf) at doopenat+0x35b sys/kern/vfs_syscalls.c:1155
sys_openat(ffff80003abd8d18,ffff80003a3bdeb0,ffff80003a3bde00) at sys_openat+0x58 sys/kern/vfs_syscalls.c:1094
syscall(ffff80003a3bdeb0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003a3bdeb0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x6c57f48d370, count: -12
ddb{0}>