login: panic: fifo_badop called
Stopped at      db_enter+0x18:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*212084  54159      0         0x2          0    0  syz-executor.1
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic() at panic+0x15c sys/kern/subr_prf.c:207
fifo_badop(ffff8000149ee128) at fifo_badop+0x14 sys/miscfs/fifofs/fifo_vnops.c:491
VOP_STRATEGY(fffffd803275ba00) at VOP_STRATEGY+0x99 sys/kern/vfs_vops.c:715
bwrite(fffffd803275ba00) at bwrite+0x203 sys/kern/vfs_bio.c:738
VOP_BWRITE(fffffd803275ba00) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:727
ufs_mkdir(ffff8000149ee3b8) at ufs_mkdir+0x6c0 sys/ufs/ufs/ufs_vnops.c:1250
VOP_MKDIR(fffffd803c56b598,ffff8000149ee510,ffff8000149ee560,ffff8000149ee440) at VOP_MKDIR+0x6a sys/kern/vfs_vops.c:449
domkdirat(ffff8000ffff9b30,ffffff9c,7f7ffffd26e0,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:2971
syscall(ffff8000149ee6e0) at syscall+0x508
Xsyscall(6,88,7f7ffffd26e0,88,0,7f7ffffd2704) at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffd2750, count: 4
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ddb> 
ddb> set $lines = 0
ddb> set $maxwidth = 0
ddb> show panic
fifo_badop called
ddb> trace
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic() at panic+0x15c sys/kern/subr_prf.c:207
fifo_badop(ffff8000149ee128) at fifo_badop+0x14 sys/miscfs/fifofs/fifo_vnops.c:491
VOP_STRATEGY(fffffd803275ba00) at VOP_STRATEGY+0x99 sys/kern/vfs_vops.c:715
bwrite(fffffd803275ba00) at bwrite+0x203 sys/kern/vfs_bio.c:738
VOP_BWRITE(fffffd803275ba00) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:727
ufs_mkdir(ffff8000149ee3b8) at ufs_mkdir+0x6c0 sys/ufs/ufs/ufs_vnops.c:1250
VOP_MKDIR(fffffd803c56b598,ffff8000149ee510,ffff8000149ee560,ffff8000149ee440) at VOP_MKDIR+0x6a sys/kern/vfs_vops.c:449
domkdirat(ffff8000ffff9b30,ffffff9c,7f7ffffd26e0,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:2971
syscall(ffff8000149ee6e0) at syscall+0x508
Xsyscall(6,88,7f7ffffd26e0,88,0,7f7ffffd2704) at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffd2750, count: -11
ddb>