assert "amap->am_buckets[bucket] == NULL" failed in uvm_amap.c (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 15ef65f2835f make ttm_device_prepare_hibernation() return ..
git tree: openbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=178ec4da580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7058272de1526588
dashboard link: https://syzkaller.appspot.com/bug?extid=5c5c60145b9e15bf6f29

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/77675697292d/disk-15ef65f2.raw.xz
bsd.gdb: https://storage.googleapis.com/syzbot-assets/aceb614d1439/bsd-15ef65f2.gdb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5088c9860323/kernel-15ef65f2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5c5c60...@syzkaller.appspotmail.com

panic: kernel diagnostic assertion "amap->am_buckets[bucket] == NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/uvm/uvm_amap.c", line 138
Starting stack trace...
panic(ffffffff834487e9) at panic+0x1d0 sys/kern/subr_prf.c:229
__assert(ffffffff83488965,ffffffff8344cf51,8a,ffffffff834af47c) at __assert+0x29 sys/kern/subr_prf.c:-1
amap_chunk_get(fffffd806c5f19b8,38,1,2) at amap_chunk_get+0x2fd
amap_add(fffffd806ff67c58,38000,fffffd805e062980,0) at amap_add+0xb1 sys/uvm/uvm_amap.c:-1
uvm_fault_lower(ffff80002a1cc7b0,ffff80002a1cc7e8,ffff80002a1cc730) at uvm_fault_lower+0x98f sys/uvm/uvm_fault.c:1468
uvm_fault(fffffd800b063d58,ea706c32000,0,2) at uvm_fault+0x274 sys/uvm/uvm_fault.c:-1
upageflttrap(ffff80002a1cc950,ea706c32000) at upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192
usertrap(ffff80002a1cc950) at usertrap+0x430 sys/arch/amd64/amd64/trap.c:640
recall_trap() at recall_trap+0x8
end of kernel
end trace frame: 0x7ed934836950, count: 248
End of stack trace.


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