last executing test programs:

1.331326628s ago: executing program 0:
mknod(&(0x7f00000000c0)='./bus\x00', 0x2000, 0x4f4b)
__posix_rename(&(0x7f0000000000)='./bus/\x00', &(0x7f0000000040)='./bus/\x00')
mknod(&(0x7f0000000000)='./file0\x00', 0x2000, 0x0)
mkdir(&(0x7f0000000080)='./file0\x00', 0x0)
__mount50(&(0x7f0000000180)='kernfs\x00', &(0x7f0000000380)='./file0\x00', 0x0, 0x0, 0x0)
compat_40_mount(0x0, &(0x7f0000000040)='./file0\x00', 0x0, 0x0)
__clone(0x0, &(0x7f00000000c0))
open(&(0x7f00000000c0)='./file0\x00', 0x0, 0x0)
compat_50_wait4(0x0, &(0x7f0000000100), 0x4, 0x0)
modctl$MODCTL_LOAD(0x0, &(0x7f0000000140)={&(0x7f0000000040), 0x0, 0x0})
__posix_rename(&(0x7f00000001c0)='./bus\x00', &(0x7f0000000200)='./bus/\x00')
r0 = open$dir(&(0x7f0000000000)='./file0\x00', 0x2, 0x0)
writev(r0, &(0x7f0000000640)=[{&(0x7f00000007c0)="6cb834d3f8dbf80ec8a7e7f2dc2a6aee4de40a9667e753384ae32c9c8366c7084adc130a6a52cd049c2bab6b8200a09867ed00f42ce6d6069376a457c79b2fbc60038584e78622b173ede3f54e7838c2888b0000000000000000000000000000002f1596ac929c3aeeb6049f731d2d6b0ade5b8a94fde0c3016dd0eb504ce846b810677a2fa984d7d6c892cceef6a0924529fd6877700f00d933f1b57233d0afa1380f3459f49a3dd671459a13f87a7e2d7b2c68300228de9b9647f45c88cb24d679b0e1a9557055d2025255336251b5714216de5b5f7bea241b842e77b893c5d1572ff90ecac336", 0x16}, {&(0x7f0000000240)="7f8ce9cb41822760720b4f76a092cc1d61aad658a740c87efd4bc9c154cd510fba31a0963389e035d5e85cb7b22c58901d4ec37674da6d31e6a40d1334226093220a249a7fca9f3dd04758ddd218c3298032fb59901ac7253c7a6524fed2bea1ad6d774288bbfb2162a7d74f33d0f00de3c606365260073d82ca5ae80295c024a8b967ceb7d1c1c88fa0a350ddae1415cb34c8b32ebee37d4caabea24203257f03902163a591712be14d246d036723fba43305d901039529e5aa280234bf63e91ab4022e3a27973eb66ed23d3df8fb", 0xfffffda4}, {&(0x7f00000003c0)="bf63df8c1fea96ff2fc81067d7b74be5323e631c849910b37c3a5d986e9d203518bfd57bfb8f5b45674fb6e74e1c6cdd9ac343181b3152381681c057009fa2c16645bc199f2a385875ccb2c32e51236f3f932f69d2e0833eba4c58e23cf9e62aaa9a0792230868064298698bf7cd1f47dac4d9cc1f9c0c03048e13e922c5e2df1f0d57ea0c54ad69682dd85fc15bbf745865c70cc4d21ed77e68e8dacac5fd716ead0bfc61aa7d245defd2cb1905f3dc2637f8eaf4f2fa20d618625622ad47bf77d261851b227c9c23594268c0e7e2f5507cc537d62b4d7755da34f4", 0xdc}, {&(0x7f0000000100)="e274f12425af1d1da50be4e6546c95ba52612251db0b4c117320cbd9c955355a6fbbee14c89bd3908b47e5c60cf4ff1632dfe0", 0x33}, {&(0x7f00000004c0)="43e3e4211eba3b75017277b693578d9ae805c9e850e2448b4bc78a2465a3df116376ae7dd961e384d18333e6e49f562315c14c44b52934eb846620260204a2dbf7f850e6aefd891b4628cb4d6b3f9bebd2811ca5a84d4d0f56cfedbd213e5f5abf382466461dee727eefd0bac8a8cf1a97d4ce8c90462ab9a252cbaa618f7e4b7f60fce009bfa47d220695cdff", 0x8d}, {&(0x7f0000000580)="c21ee799d3363aea85f69d08a136eb323793d9db0f1c2b5b3753b6529b11661bda9607330b3ac2e945b76c59f69d00c2ec69d579f67206924119dd4fe1968c5d13a6b29b53acf2965462aa24fdac1f4612c5f5f53eb4d762505cc089b48258198d166c5b23619aedfeefc13e73bfd5912b7334db2594da22bf33dee60d9ea2e7daeda1876421dfbb799194", 0x8b}, {&(0x7f0000000340)="c8b97b362936ebb80640307ecd6326693909f70d9fb1b299c4cc9e858561200b3795d98493", 0x25}], 0x7)

223.994637ms ago: executing program 5:
mkdir(&(0x7f0000000080)='./file0\x00', 0x0)
compat_50___msgctl13$IPC_STAT(0x0, 0x2, &(0x7f0000001400)={{}, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, &(0x7f00000001c0)={&(0x7f0000000100)}})
compat_40_mount(&(0x7f0000000040)='ptyfs\x00', &(0x7f00000002c0)='./file0\x00', 0x0, &(0x7f0000000500))
lchown(&(0x7f0000000100)='./file0\x00', 0x0, 0xffffffffffffffff)
compat_40_mount(&(0x7f0000000000)='null\x00', &(0x7f0000000140)='./file0\x00', 0x0, &(0x7f00000001c0))
compat_50___msgctl13$IPC_STAT(0x0, 0x2, &(0x7f0000000280)={{}, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, &(0x7f00000001c0)={&(0x7f0000000100), 0xdffffffffefff7ff}}) (async)
renameat(0xffffffffffffffff, 0x0, 0xffffffffffffffff, 0x0)
socket(0x0, 0x0, 0x0) (async, rerun: 64)
shmctl$IPC_RMID(0x0, 0x0) (async, rerun: 64)
r0 = socket$unix(0x1, 0x5, 0x0)
bind$unix(r0, &(0x7f0000000200)=@file={0xd570d0466b6018f, './file0\x00'}, 0xa) (async, rerun: 32)
listen(r0, 0x0) (async, rerun: 32)
r1 = socket$unix(0x1, 0x5, 0x0)
connect$unix(r1, &(0x7f0000000000)=@file={0xd1653077bafa0114, './file0\x00'}, 0xa) (async)
r2 = socket$unix(0x1, 0x5, 0x0)
connect$unix(r2, &(0x7f0000000000)=@file={0xd1653077bafa0114, './file0\x00'}, 0xa) (async, rerun: 32)
lchown(&(0x7f0000000100)='./file0\x00', 0x0, 0xffffffffffffffff) (rerun: 32)
compat_40_mount(&(0x7f0000000380)='union\x00', &(0x7f0000000140)='./file0\x00', 0x0, &(0x7f00000001c0))

4.31235ms ago: executing program 2:
mkdir(&(0x7f0000000080)='./file0\x00', 0x0)
compat_40_mount(&(0x7f0000000040)='ptyfs\x00', &(0x7f00000002c0)='./file0\x00', 0x0, &(0x7f0000000500))
socket$inet(0x2, 0x3, 0x0)
modctl$MODCTL_LOAD(0x0, &(0x7f0000000080)={0x0, 0x0, 0x0, 0xc1})
socket(0x1d, 0x40000003, 0x0)
swapctl$SWAP_OFF(0x6, 0x0)
r0 = open(&(0x7f0000000080)='./file0\x00', 0x1, 0x80)
ioctl$FIOASYNC(r0, 0x4004667f, &(0x7f0000000000))
swapctl$SWAP_OFF(0x2, 0x0)
mknod(&(0x7f00000000c0)='./file0\x00', 0x0, 0xe03)
compat_50___msgctl13$IPC_STAT(0x0, 0x2, 0x0)
lchown(0x0, 0x0, 0xffffffffffffffff)
link(0x0, 0x0)
compat_20_fstatfs(0xffffffffffffffff, &(0x7f0000000580))
__stat50(&(0x7f0000000240)='./file0\x00', &(0x7f00000004c0))
mknod(&(0x7f00000000c0)='./bus\x00', 0x2000, 0x0)
r1 = open$dir(&(0x7f0000000000)='./bus\x00', 0x0, 0x0)
ioctl$FIOASYNC(r1, 0x4004667f, &(0x7f0000000040)=0x1ff)

0s ago: executing program 5:
mkdir(&(0x7f0000000200)='./file0\x00', 0x0)
r0 = socket$inet(0x2, 0x2, 0x0)
truncate(0x0, 0x0, 0x0)
compat_40_mount(0x0, 0x0, 0x0, 0x0)
mknod(&(0x7f0000000280)='./file0\x00', 0x0, 0x0)
open(0x0, 0x0, 0x0)
writev(0xffffffffffffffff, 0x0, 0x0)
compat_43_ocreat(0x0, 0x0)
semop(0x0, 0x0, 0x0)
madvise(&(0x7f0000000000/0x800000)=nil, 0x800000, 0x6)
mlock(&(0x7f0000ffc000/0x3000)=nil, 0x3000)
munmap(&(0x7f0000001000/0x3000)=nil, 0x3000)
r1 = shmget$private(0x0, 0x3000, 0x0, &(0x7f0000ffa000/0x3000)=nil)
shmat(r1, &(0x7f0000001000/0x3000)=nil, 0x0)
mincore(&(0x7f0000003000/0x3000)=nil, 0x3000, &(0x7f0000000c80)=""/231)
recvfrom$inet(r0, 0x0, 0x0, 0xc09, 0x0, 0x0)
compat_50___msgctl13$IPC_STAT(0x0, 0x2, &(0x7f0000000240)={{}, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, &(0x7f00000001c0)={&(0x7f0000000080)={0x0, 0xffffffff}, 0x0, 0x4000, 0x9}})
mknod(&(0x7f0000000100)='./bus\x00', 0x2000, 0x0)
compat_40_mount(&(0x7f0000000000)='null\x00', &(0x7f0000000140)='./file0\x00', 0x0, &(0x7f00000001c0))
compat_50_quotactl(&(0x7f0000000000)='./file0\x00', 0x10001, 0x0, &(0x7f0000000040))

kernel console output (not intermixed with test programs):

Warning: Permanently added '10.128.0.194' (ED25519) to the list of known hosts.
2024/05/31 21:18:10 fuzzer started
2024/05/31 21:18:10 dialing manager at 10.128.0.163:30038
2024/05/31 21:18:10 starting 6 executor processes
l¸4ÓøÛ[  54.8532167] cpu1[1244 syz-executor.0]: hogging kernel lock
[  54.8732302] ipi_msg_cpu_handler() at netbsd:ipi_msg_cpu_handler+0x16a
[  54.9132326] ipi_cpu_handler() at netbsd:ipi_cpu_handler+0x159
[  54.9432215] x86_ipi_handler() at netbsd:x86_ipi_handler+0x1a2
[  54.9732233] Xresume_lapic_ipi() at netbsd:Xresume_lapic_ipi+0x18
[  54.9832209] --- interrupt ---
[  55.0032251] panic: cpu0: softints stuck for 16 seconds
[  55.0032251] cpu0: Begin traceback...
[  55.0032251] __sanitizer_cov_trace_pc() at netbsd:__sanitizer_cov_trace_pc+0x88
[  55.0032251] vpanic() at netbsd:vpanic+0x2f0
[  55.0032251] ttwrite() at netbsd:ttwrite+0xad1
[  55.0032251] panic() at comwrite() at netbsd:panic+0x49
[  55.0032251] netbsd:comwrite+0x135
[  55.0032251] heartbeat() at cdev_write() at netbsd:heartbeat+0x7c3
[  55.0032251] netbsd:cdev_write+0x14c
[  55.0032251] hardclock() at cnwrite() at netbsd:hardclock+0x1d9
[  55.0032251] netbsd:cnwrite+0xcb
[  55.0032251] Xresume_lapic_ltimer() at cdev_write() at netbsd:Xresume_lapic_ltimer+0x1e
[  55.0032251] --- interrupt ---
[  55.0032251] netbsd:cdev_write+0x14c
[  55.0032251] ipi_wait() at spec_write() at netbsd:ipi_wait+0x10b
[  55.0032251] netbsd:spec_write+0x278
[  55.0032251] _kernel_lock() at VOP_WRITE() at netbsd:_kernel_lock+0x53b
[  55.0032251] netbsd:VOP_WRITE+0x2ab
[  55.0032251] intr_biglock_wrapper() at vn_write() at netbsd:intr_biglock_wrapper+0x23
[  55.0032251] netbsd:vn_write+0x309
[  55.0032251] Xhandle_ioapic_edge19() at netbsd:Xhandle_ioapic_edge19+0x75
[  55.0032251] --- interrupt ---
[  55.0032251] do_filewritev.part.0() at netbsd:do_filewritev.part.0+0x56d
[  55.0032251] __sanitizer_cov_trace_pc() at netbsd:__sanitizer_cov_trace_pc+0x16
[  55.0032251] sys_writev() at netbsd:sys_writev+0x5e
[  55.0032251] _kernel_lock() at netbsd:_kernel_lock+0x491
[  55.0032251] sys___syscall() at netbsd:sys___syscall+0x1e4
[  55.0032251] softint_dispatch() at netbsd:softint_dispatch+0xada
[  55.0032251] Skipping crash dump on recursive panic
[  55.0032251] panic: UBSan: Undefined Behavior in /syzkaller/managers/ci2-netbsd-kubsan/kernel/sys/arch/amd64/amd64/db_machdep.c:125:24, member access within misaligned address 0x98fe for type 'struct x86_64_frame' which requires 8 byte alignment

[  55.0032251] Faulted in mid-traceback; aborting...
[  55.0032251] syscall() at fatal breakpoint trap in supervisor mode
[  55.0032251] trap type 1 code 0 rip 0xffffffff80235475 cs 0x8 rflags 0x202 cr2 0x7e0ee12f6f68 ilevel 0x7 rsp 0xffffa4022fa37c30
[  55.0032251] curlwp 0xffffd7caacfc24c0 pid 0.6 lowest kstack 0xffffa4022fa342c0
Stopped in pid 0.6 (system) at  netbsd:breakpoint+0x5:  leave
?
breakpoint() at netbsd:breakpoint+0x5
db_panic() at netbsd:db_panic+0xec
vpanic() at netbsd:vpanic+0x2f0
Report() at netbsd:Report+0x3b
HandleTypeMismatch() at netbsd:HandleTypeMismatch+0xfc
db_nextframe() at netbsd:db_nextframe+0x790
db_stack_trace_print() at netbsd:db_stack_trace_print+0x281
db_panic() at netbsd:db_panic+0x9d
vpanic() at netbsd:vpanic+0x2f0
panic() at netbsd:panic+0x49
heartbeat() at netbsd:heartbeat+0x7c3
hardclock() at netbsd:hardclock+0x1d9
Xresume_lapic_ltimer() at netbsd:Xresume_lapic_ltimer+0x1e
--- interrupt ---
ipi_wait() at netbsd:ipi_wait+0x10b
_kernel_lock() at netbsd:_kernel_lock+0x53b
intr_biglock_wrapper() at netbsd:intr_biglock_wrapper+0x23
Xhandle_ioapic_edge19() at netbsd:Xhandle_ioapic_edge19+0x75
--- interrupt ---
__sanitizer_cov_trace_pc() at netbsd:__sanitizer_cov_trace_pc+0x16
_kernel_lock() at netbsd:_kernel_lock+0x491
softint_dispatch() at netbsd:softint_dispatch+0xada