panic: kernel diagnostic assertion "len >= 0 && !M_READONLY(m)" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/uipc_mbuf.c", line 1384
Starting stack trace...
panic(ffffffff82577da7) at panic+0x16b sys/kern/subr_prf.c:233
__assert(ffffffff825ebc34,ffffffff8255f654,568,ffffffff8258dc04) at __assert+0x25 sys/kern/subr_prf.c:161
m_align(fffffd806276b000,ffffffbe) at m_align+0x1a0 sys/kern/uipc_mbuf.c:1385
bpf_movein(ffff800025c1b200,ffff800000d54200,ffff800025c1aee8,ffff800025c1ade8) at bpf_movein+0x25e sys/net/bpf.c:228

bpfwrite(61700,ffff800025c1b200,1) at bpfwrite+0x169 sys/net/bpf.c:644
spec_write(ffff800025c1afe0) at spec_write+0xd4 sys/kern/spec_vnops.c:309
VOP_WRITE(fffffd805ef0bc58,ffff800025c1b200,1,fffffd807f7d85a0) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245
vn_write(fffffd805c4653a0,ffff800025c1b200,0) at vn_write+0x157 sys/kern/vfs_vnops.c:414
dofilewritev(ffff8000294ee008,4,ffff800025c1b200,0,ffff800025c1b300) at dofilewritev+0x19c sys/kern/sys_generic.c:381
sys_writev(ffff8000294ee008,ffff800025c1b2a8,ffff800025c1b300) at sys_writev+0xa7 sys/kern/sys_generic.c:328
syscall(ffff800025c1b370) at syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline]
syscall(ffff800025c1b370) at syscall+0x489 sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xaa570a5f070, count: 245
End of stack trace.
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