panic: kernel diagnostic assertion "dupe == NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/uvm/uvm_page.c", line 140
Stopped at      db_enter+0x18:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
 443202   4100      0           0          0    0  syz-executor.0
*370201   4100      0           0  0x4000000    1K syz-executor.0
db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398
panic() at panic+0x15c sys/kern/subr_prf.c:207
__assert(ffffffff82209993,ffffffff821a5572,8c,ffffffff8219459c) at __assert+0x2b sys/kern/subr_prf.c:154
uvm_pagealloc(fffffd8061aee140,e7b000,0,3) at uvm_pagealloc+0x476 sys/uvm/uvm_page.c:140
pmap_get_ptp(fffffd8061aee0f8,39ee0b9b000) at pmap_get_ptp+0xe8 sys/arch/amd64/amd64/pmap.c:1103
pmap_enter(fffffd8061aee0f8,39ee0b9b000,72dcb000,5,20) at pmap_enter+0x2a8
uvm_fault(fffffd807f00a730,39ee0b9c000,0,4) at uvm_fault+0xad6 sys/uvm/uvm_fault.c:803
pageflttrap() at pageflttrap+0x20b sys/arch/amd64/amd64/trap.c:199
usertrap(ffff8000239b70b0) at usertrap+0x21a sys/arch/amd64/amd64/trap.c:369
recall_trap() at recall_trap+0x8
end of kernel
end trace frame: 0x3a1cf55dec0, count: 5
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