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(ffffffff82958f3a) at panic+0x16f sys/kern/subr_prf.c:229
__assert(ffffffff8290c161,ffffffff828b2ba7,eb,ffffffff82898157) at __assert+0x29 sys/kern/subr_prf.c:157
buf_unmap(fffffd806788e268) at buf_unmap+0x1a8 sys/kern/vfs_biomem.c:235
buf_map(fffffd807d1ec358) at buf_map+0x1e6 sys/kern/vfs_biomem.c:117
buf_get(fffffd805d4febe8,0,4000) at buf_get+0x45f sys/kern/vfs_bio.c:1175
getblk(fffffd805d4febe8,0,4000,0,ffffffffffffffff) at getblk+0xfd sys/kern/vfs_bio.c:1044
ffs2_balloc(fffffd807d295aa0,0,e,fffffd807f7d79c0,1,ffff80003739d958) at ffs2_balloc+0x688 sys/ufs/ffs/ffs_balloc.c:539
ffs_write(ffff80003739d9e0) at ffs_write+0x3c7 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(fffffd805d4febe8,ffff80003739dc00,1,fffffd807f7d79c0) at VOP_WRITE+0xc3 sys/kern/vfs_vops.c:245
vn_write(fffffd807b5966a8,ffff80003739dc00,0) at vn_write+0x15c sys/kern/vfs_vnops.c:408
dofilewritev(ffff80002a226f90,5,ffff80003739dc00,0,ffff80003739dcc0) at dofilewritev+0x1a9 sys/kern/sys_generic.c:375
sys_writev(ffff80002a226f90,ffff80003739dd70,ffff80003739dcc0) at sys_writev+0xab sys/kern/sys_generic.c:322
syscall(ffff80003739dd70) at syscall+0x8cf mi_syscall sys/sys/syscall_mi.h:180 [inline]
syscall(ffff80003739dd70) at syscall+0x8cf sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xa7b670d4670, count: 243
End of stack trace.