panic: kernel diagnostic assertion "bp->b_data != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/vfs_biomem.c", line 235
Starting stack trace...
panic(ffffffff833ab8e6) at panic+0x1d0 sys/kern/subr_prf.c:229
__assert(ffffffff833ee3f5,ffffffff8334f916,eb,ffffffff833c7c62) at __assert+0x29 sys/kern/subr_prf.c:-1
buf_unmap(fffffd8073b3cc48) at buf_unmap+0x20a
buf_map(fffffd805f75fd50) at buf_map+0x261 sys/kern/vfs_biomem.c:117
buf_get(fffffd806b7b8538,1cf,4000) at buf_get+0x602 sys/kern/vfs_bio.c:1163
getblk(fffffd806b7b8538,1cf,4000,0,ffffffffffffffff) at getblk+0x146 sys/kern/vfs_bio.c:-1
ffs2_balloc(fffffd806c87d730,73c000,4000,fffffd80097fd410,2,ffff80003c4ef588) at ffs2_balloc+0x179c sys/ufs/ffs/ffs_balloc.c:-1
ffs_write(ffff80003c4ef610) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(fffffd806b7b8538,ffff80003c4ef7c8,7,fffffd80097fd410) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245
vn_write(fffffd806ca8e540,ffff80003c4ef7c8,0) at vn_write+0x1d3 sys/kern/vfs_vnops.c:408
dofilewritev(ffff80003c4ba038,3,ffff80003c4ef7c8,0,ffff80003c4ef880) at dofilewritev+0x242 sys/kern/sys_generic.c:380
sys_write(ffff80003c4ba038,ffff80003c4ef930,ffff80003c4ef880) at sys_write+0xa2 sys/kern/sys_generic.c:300
syscall(ffff80003c4ef930) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c4ef930) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x35bad6e3680, count: 243
End of stack trace.