panic: kernel diagnostic assertion "dupe == NULL" failed: file "/syzkaller/managers/main/kernel/sys/uvm/uvm_page.c", line 144 Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *512195 93795 0 0x8000002 0 0 syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff830a6e94) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff8305f310,ffffffff82fac128,90,ffffffff83061b91) at __assert+0x29 uvm_pagealloc_pg(fffffd8007265800,fffffd807e36f388,382fbff000,0) at uvm_pagealloc_pg+0x521 sys/uvm/uvm_page.c:695 uvm_pagealloc(fffffd807e36f388,382fbff000,0,3) at uvm_pagealloc+0x23e sys/uvm/uvm_page.c:912 pmap_get_ptp(fffffd807e36f378,705f7fef5000) at pmap_get_ptp+0x1c6 pmap_enter(fffffd807e36f378,705f7fef5000,65c0f000,1,20) at pmap_enter+0x395 uvm_fault_upper_lookup(ffff80002a583d50,ffff80002a583d88,ffff80002a583c50,ffff80002a583cd0) at uvm_fault_upper_lookup+0x368 uvm_fault(fffffd807e305d88,705f7fef6000,0,1) at uvm_fault+0x149 sys/uvm/uvm_fault.c:605 upageflttrap(ffff80002a583ed0,705f7fef6c50) at upageflttrap+0xa0 sys/arch/amd64/amd64/trap.c:188 usertrap(ffff80002a583ed0) at usertrap+0x2bc sys/arch/amd64/amd64/trap.c:436 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x705f7fef6c70, count: 3 https://www.openbsd.org/ddb.html describes the minimum info required in bug reports. Insufficient info makes it difficult to find and fix bugs. ddb> ddb> set $lines = 0 ddb> set $maxwidth = 0 ddb> show panic *cpu0: kernel diagnostic assertion "dupe == NULL" failed: file "/syzkaller/managers/main/kernel/sys/uvm/uvm_page.c", line 144 ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff830a6e94) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff8305f310,ffffffff82fac128,90,ffffffff83061b91) at __assert+0x29 uvm_pagealloc_pg(fffffd8007265800,fffffd807e36f388,382fbff000,0) at uvm_pagealloc_pg+0x521 sys/uvm/uvm_page.c:695 uvm_pagealloc(fffffd807e36f388,382fbff000,0,3) at uvm_pagealloc+0x23e sys/uvm/uvm_page.c:912 pmap_get_ptp(fffffd807e36f378,705f7fef5000) at pmap_get_ptp+0x1c6 pmap_enter(fffffd807e36f378,705f7fef5000,65c0f000,1,20) at pmap_enter+0x395 uvm_fault_upper_lookup(ffff80002a583d50,ffff80002a583d88,ffff80002a583c50,ffff80002a583cd0) at uvm_fault_upper_lookup+0x368 uvm_fault(fffffd807e305d88,705f7fef6000,0,1) at uvm_fault+0x149 sys/uvm/uvm_fault.c:605 upageflttrap(ffff80002a583ed0,705f7fef6c50) at upageflttrap+0xa0 sys/arch/amd64/amd64/trap.c:188 usertrap(ffff80002a583ed0) at usertrap+0x2bc sys/arch/amd64/amd64/trap.c:436 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x705f7fef6c70, count: -12 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002a583870 rbx 0x382fbff000 rdx 0 rcx 0 rax 0xffff80002a491968 r8 0x101010101010101 r9 0x8080808080808080 r10 0x78f6d4b22cb8950d r11 0xe2efa205a0f3ff83 r12 0 r13 0x382fbff000 r14 0 r15 0x1 rip 0xffffffff81c86095 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a583860 ss 0 db_enter+0x25: addq $0x8,%rsp ddb> show proc PROC (syz-executor) tid=512195 pid=93795 tcnt=1 stat=onproc flags process=8000002 proc=0 runpri=32, usrpri=84, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80002a490528,0xffff80002a491c00 process=0xffff8000376ad560 user=0xffff80002a57e000, vmspace=0xfffffd807e305d88 estcpu=34, cpticks=1, pctcpu=0.0, user=0, sys=3, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 43705 224563 30157 0 2 0x8000000 syz-executor 43705 425547 30157 0 2 0xc000000 syz-executor 26142 441994 56315 0 2 0x8000000 syz-executor 57196 15683 26891 60928 2 0x8000010 syz-executor 57196 276037 26891 60928 3 0xc000090 fsleep syz-executor 57196 467596 26891 60928 2 0xc000010 syz-executor 60874 17618 85325 0 2 0x8000000 syz-executor 60874 27884 85325 0 2 0xc000000 syz-executor 60874 67079 85325 0 3 0xc000080 fsleep syz-executor 40638 271913 93795 0 2 0x8000000 syz-executor 40638 264320 93795 0 2 0xc000080 syz-executor 40638 66700 93795 0 3 0xc000080 fsleep syz-executor 42891 249387 14493 0 2 0x8000010 syz-executor 42891 128943 14493 0 3 0xc000090 fsleep syz-executor 42891 218425 14493 0 3 0xc000090 fsleep syz-executor 42891 182612 14493 0 2 0xc000010 syz-executor 22566 42591 12495 0 3 0x8000080 nanoslp syz-executor 22566 520567 12495 0 3 0xc000080 fsleep syz-executor 22566 71130 12495 0 3 0xc000080 kqread syz-executor 30157 355290 322 0 3 0x8000082 nanoslp syz-executor 56315 246164 322 0 2 0x8000003 syz-executor *93795 512195 322 0 7 0x8000002 syz-executor 85325 131332 322 0 2 0x8000003 syz-executor 14493 89059 322 0 2 0x8000003 syz-executor 12495 20399 322 0 3 0x8000082 nanoslp syz-executor 95821 357453 322 0 3 0x8000082 wait syz-executor 26891 497480 322 0 2 0x8000003 syz-executor 72227 175212 1 0 3 0x18100083 ttyin getty 49967 43500 0 0 3 0x14200 bored sosplice 322 432403 26865 0 3 0x8000082 kqread syz-executor 26865 356602 59710 0 3 0x810008a sigsusp ksh 59710 380248 3434 0 3 0x18000098 kqread sshd-session 3434 358562 24915 0 3 0x18000092 kqread sshd-session 24915 305604 1 0 3 0x18000088 kqread sshd 22098 56315 69538 73 2 0x19100011 syslogd 69538 469239 1 0 3 0x18100082 sbwait syslogd 55527 203956 1 0 3 0x18100080 kqread resolvd 25374 503300 41553 77 3 0x18100092 kqread dhcpleased 81469 116800 41553 77 3 0x18100092 kqread dhcpleased 41553 91807 1 0 3 0x18000080 kqread dhcpleased 14996 133473 0 0 3 0x14200 bored smr 92685 126005 0 0 2 0x14200 zerothread 91007 324940 0 0 3 0x14200 aiodoned aiodoned 11190 369068 0 0 3 0x14200 syncer update 82459 178468 0 0 3 0x14200 cleaner cleaner 23882 124403 0 0 3 0x14200 reaper reaper 44275 149773 0 0 3 0x14200 pgdaemon pagedaemon 55006 253654 0 0 3 0x14200 bored viomb 1727 280191 0 0 3 0x40014200 acpi0 acpi0 23574 392473 0 0 3 0x14200 bored softnet3 35223 491881 0 0 3 0x14200 bored softnet2 65969 66946 0 0 3 0x14200 bored softnet1 31765 419463 0 0 3 0x14200 bored softnet0 55163 380291 0 0 3 0x14200 bored systqmp 74017 372712 0 0 3 0x14200 bored systq 48441 270151 0 0 3 0x40014200 tmoslp softclock 56211 294258 0 0 3 0x40014200 idle0 1 358883 0 0 3 0x8080082 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10216 10173K 11752K 166960K 14236 0 pcb 17 16K 18K 166960K 421 0 rtable 211 7K 7K 166960K 1654 0 pf 36 14K 17K 166960K 168 0 ifaddr 42 8K 8K 166960K 206 0 ifgroup 58 2K 2K 166960K 262 0 sysctl 3 1K 1K 166960K 3 0 counters 32 17K 18K 166960K 87 0 ioctlops 0 0K 4K 166960K 178 0 iov 0 0K 16K 166960K 80 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1500 94K 95K 166960K 2922 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 9K 166960K 22 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 292 0 dirhash 12 2K 3K 166960K 39 0 ACPI 1697 195K 286K 166960K 12548 0 file desc 18 65K 97K 166960K 1511 0 sigio 0 0K 0K 166960K 24 0 proc 58 59K 124K 166960K 1495 0 subproc 104 6K 6K 166960K 525 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 141 0 in_multi 86 6K 7K 166960K 479 0 ether_multi 1 0K 0K 166960K 7 0 mrt 1 0K 0K 166960K 2 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 289 1288K 1288K 166960K 289 0 exec 0 0K 1K 166960K 937 0 pfkey data 0 0K 0K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 246 94K 110K 166960K 13865 0 UVM aobj 99 5K 5K 166960K 103 0 pinsyscall 39 78K 96K 166960K 3370 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 1K 166960K 51 0 NDP 13 0K 1K 166960K 148 0 temp 109 6808K 6948K 166960K 63626 0 kqueue 13 20K 30K 166960K 151 0 SYN cache 2 16K 16K 166960K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 453 0 450 4 2 2 3 0 8 1 rtentry 112 528 0 434 4 1 3 4 0 8 0 unpcb 144 1578 0 1561 12 8 4 6 0 8 3 syncache 336 5 0 5 2 1 1 1 0 8 1 tcpqe 32 1 0 1 1 1 0 1 0 8 0 tcpcb 808 585 0 580 14 12 2 8 0 8 1 arp 88 85 0 67 1 0 1 1 0 8 0 ipq 40 5 0 4 1 0 1 1 0 8 0 ipqe 40 50 0 49 1 0 1 1 0 8 0 inpcb 336 2223 0 2214 22 15 7 12 0 8 6 nd6 104 133 0 111 1 0 1 1 0 8 0 pkpcb 40 8 0 8 3 2 1 1 0 8 1 kcovpl 48 40 0 32 1 0 1 1 0 8 0 ppxss 1072 12 0 12 3 2 1 1 0 8 1 pfanchor 1288 3 0 3 1 1 0 1 0 8 0 pfrule 1344 2 0 2 1 1 0 1 0 8 0 art_heap8 4096 3 0 1 3 0 3 3 0 8 1 art_heap4 256 1968 0 1579 32 4 28 29 0 8 3 art_table 32 1971 0 1580 4 0 4 4 0 8 0 art_node 16 489 0 405 1 0 1 1 0 8 0 sysvmsgpl 40 10 0 9 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 290 0 280 1 0 1 1 0 8 0 shmpl 112 100 0 4 3 0 3 3 0 8 0 dirhash 1024 36 0 19 3 0 3 3 0 8 0 dino2pl 256 3532 0 1978 98 0 98 98 0 8 0 ffsino 240 3533 0 1978 92 0 92 92 0 8 0 nchpl 144 5151 0 3430 64 0 64 64 0 8 0 uvmvnodes 80 4816 0 0 99 0 99 99 0 8 0 vnodes 216 4816 0 0 268 0 268 268 0 8 0 namei 1024 24214 0 24212 3 2 1 2 0 8 0 vcpupl 3904 8 0 1 1 0 1 1 0 8 0 vmpool 664 11 0 4 1 0 1 1 0 8 0 kstatmem 264 136 0 110 4 1 3 3 0 8 0 scsiplug 72 1 0 1 1 1 0 1 0 8 0 scxspl 216 33691 0 33691 9 8 1 8 1 8 1 plimitpl 152 580 0 564 1 0 1 1 0 8 0 sigapl 424 1749 0 1702 8 2 6 8 0 8 0 futexpl 64 20023 0 20017 1 0 1 1 0 8 0 knotepl 120 35510 0 35463 23 14 9 10 0 8 7 kqueuepl 184 495 0 484 6 5 1 4 0 8 0 pipepl 288 299 0 271 3 0 3 3 0 8 0 fdescpl 432 1712 0 1682 5 1 4 5 0 8 0 filepl 120 13838 0 13584 26 11 15 17 0 8 6 lockfpl 104 1338 0 1335 6 5 1 6 0 8 0 lockfspl 48 294 0 291 1 0 1 1 0 8 0 sessionpl 144 54 0 46 1 0 1 1 0 8 0 pgrppl 48 105 0 89 1 0 1 1 0 8 0 ucredpl 104 1987 0 1974 1 0 1 1 0 8 0 zombiepl 144 1859 0 1858 1 0 1 1 0 8 0 processpl 1088 1749 0 1702 5 1 4 5 0 8 0 procpl 648 3260 0 3201 8 2 6 7 0 8 0 sosppl 168 3 0 3 2 2 0 1 0 8 0 sockpl 504 4311 0 4282 70 58 12 26 0 8 7 mcl64k 65536 14 0 14 3 2 1 1 0 8 1 mcl16k 16384 6 0 6 2 1 1 1 0 8 1 mcl12k 12288 2 0 2 2 1 1 1 0 8 1 mcl9k 9216 1 0 1 1 0 1 1 0 8 1 mcl8k 8192 37 0 37 1 0 1 1 0 8 1 mcl4k 4096 15 0 15 3 2 1 1 0 8 1 mcl2k2 2112 4 0 4 2 1 1 1 0 8 1 mcl2k 2048 8571 0 8479 25 11 14 25 0 8 2 mtagpl 96 126 0 126 2 1 1 2 0 8 1 mbufpl 256 21489 0 21256 34 14 20 25 0 8 4 bufpl 280 8702 0 2341 455 0 455 455 0 8 0 anonpl 24 315624 0 312235 101 26 75 75 0 187 47 amapchunkpl 152 45939 0 45413 48 16 32 34 0 158 9 amappl16 200 7298 0 7277 46 35 11 15 0 8 8 amappl15 192 14 0 14 1 1 0 1 0 8 0 amappl14 184 177 0 167 1 0 1 1 0 8 0 amappl13 176 10 0 10 1 1 0 1 0 8 0 amappl12 168 2836 0 2806 3 1 2 3 0 8 0 amappl11 160 48 0 38 1 0 1 1 0 8 0 amappl10 152 13 0 12 1 0 1 1 0 8 0 amappl9 144 152 0 152 1 1 0 1 0 8 0 amappl8 136 60 0 59 1 0 1 1 0 8 0 amappl7 128 164 0 154 1 0 1 1 0 8 0 amappl6 120 485 0 483 1 0 1 1 0 8 0 amappl5 112 265 0 256 1 0 1 1 0 8 0 amappl4 104 405 0 390 1 0 1 1 0 8 0 amappl3 96 8997 0 8875 5 1 4 4 0 8 0 amappl2 88 1056 0 1000 2 0 2 2 0 8 0 amappl1 80 13610 0 13076 14 2 12 13 0 8 0 amappl 88 13199 0 13014 5 0 5 5 0 92 0 dma32768 32768 1 0 1 1 0 1 1 0 8 1 dma16384 16384 1 0 1 1 1 0 1 0 8 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 1 0 0 1 0 1 1 0 8 0 dma256 256 7 0 7 1 1 0 1 0 8 0 dma128 128 253 0 253 1 1 0 1 0 8 0 dma64 64 7 0 7 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 18 0 17 1 0 1 1 0 8 0 aobjpl 72 102 0 4 2 0 2 2 0 8 0 uaddrrnd 24 1723 0 1686 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1723 0 1686 1 0 1 1 0 8 0 vmmpekpl 168 14792 0 14750 3 0 3 3 0 8 0 vmmpepl 168 112108 0 110300 113 22 91 91 0 357 11 vmsppl 344 1722 0 1686 4 0 4 4 0 8 0 rwobjpl 24 39086 0 33296 36 0 36 36 0 8 0 pdppl 4096 3452 0 3379 159 85 74 82 0 8 1 pvpl 32 872637 0 862390 397 137 260 260 0 265 175 pmappl 216 1722 0 1686 4 1 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 579 0 211 12 0 12 12 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff830a6e94) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff8305f310,ffffffff82fac128,90,ffffffff83061b91) at __assert+0x29 uvm_pagealloc_pg(fffffd8007265800,fffffd807e36f388,382fbff000,0) at uvm_pagealloc_pg+0x521 sys/uvm/uvm_page.c:695 uvm_pagealloc(fffffd807e36f388,382fbff000,0,3) at uvm_pagealloc+0x23e sys/uvm/uvm_page.c:912 pmap_get_ptp(fffffd807e36f378,705f7fef5000) at pmap_get_ptp+0x1c6 pmap_enter(fffffd807e36f378,705f7fef5000,65c0f000,1,20) at pmap_enter+0x395 uvm_fault_upper_lookup(ffff80002a583d50,ffff80002a583d88,ffff80002a583c50,ffff80002a583cd0) at uvm_fault_upper_lookup+0x368 uvm_fault(fffffd807e305d88,705f7fef6000,0,1) at uvm_fault+0x149 sys/uvm/uvm_fault.c:605 upageflttrap(ffff80002a583ed0,705f7fef6c50) at upageflttrap+0xa0 sys/arch/amd64/amd64/trap.c:188 usertrap(ffff80002a583ed0) at usertrap+0x2bc sys/arch/amd64/amd64/trap.c:436 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x705f7fef6c70, count: -12 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff830a6e94) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff8305f310,ffffffff82fac128,90,ffffffff83061b91) at __assert+0x29 uvm_pagealloc_pg(fffffd8007265800,fffffd807e36f388,382fbff000,0) at uvm_pagealloc_pg+0x521 sys/uvm/uvm_page.c:695 uvm_pagealloc(fffffd807e36f388,382fbff000,0,3) at uvm_pagealloc+0x23e sys/uvm/uvm_page.c:912 pmap_get_ptp(fffffd807e36f378,705f7fef5000) at pmap_get_ptp+0x1c6 pmap_enter(fffffd807e36f378,705f7fef5000,65c0f000,1,20) at pmap_enter+0x395 uvm_fault_upper_lookup(ffff80002a583d50,ffff80002a583d88,ffff80002a583c50,ffff80002a583cd0) at uvm_fault_upper_lookup+0x368 uvm_fault(fffffd807e305d88,705f7fef6000,0,1) at uvm_fault+0x149 sys/uvm/uvm_fault.c:605 upageflttrap(ffff80002a583ed0,705f7fef6c50) at upageflttrap+0xa0 sys/arch/amd64/amd64/trap.c:188 usertrap(ffff80002a583ed0) at usertrap+0x2bc sys/arch/amd64/amd64/trap.c:436 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x705f7fef6c70, count: -12