panic: kernel diagnostic assertion "dupe == NULL" failed: file "/syzkaller/managers/main/kernel/sys/uvm/uvm_page.c", line 144 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *209670 50320 0 0 0x4000000 0 syz-executor.1 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff8242cc29) at panic+0x161 sys/kern/subr_prf.c:202 __assert(ffffffff8249d790,ffffffff82453283,90,ffffffff8240b983) at __assert+0x25 sys/kern/subr_prf.c:161 uvm_pagealloc_pg(fffffd8006448800,fffffd8072f2b890,466f32000,0) at uvm_pagealloc_pg+0x427 uvm_pageinsert sys/uvm/uvm_page.c:138 [inline] uvm_pagealloc_pg(fffffd8006448800,fffffd8072f2b890,466f32000,0) at uvm_pagealloc_pg+0x427 sys/uvm/uvm_page.c:710 uvm_pagealloc(fffffd8072f2b890,466f32000,0,3) at uvm_pagealloc+0x1e8 sys/uvm/uvm_page.c:918 pmap_get_ptp(fffffd8072f2b880,8cde651d000) at pmap_get_ptp+0x18d sys/arch/amd64/amd64/pmap.c:1183 pmap_enter(fffffd8072f2b880,8cde651d000,6d47a000,1,20) at pmap_enter+0x292 sys/arch/amd64/amd64/pmap.c:2697 uvm_fault_upper_lookup(ffff800027f554f0,ffff800027f55528,ffff800027f553f0,ffff800027f55470) at uvm_fault_upper_lookup+0x291 sys/uvm/uvm_fault.c:887 uvm_fault(fffffd806aea4230,8cde6520000,0,1) at uvm_fault+0x119 sys/uvm/uvm_fault.c:607 upageflttrap(ffff800027f55660,8cde6520028) at upageflttrap+0x79 sys/arch/amd64/amd64/trap.c:181 usertrap(ffff800027f55660) at usertrap+0x198 sys/arch/amd64/amd64/trap.c:403 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x8cd88810fe0, 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+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff8242cc29) at panic+0x161 sys/kern/subr_prf.c:202 __assert(ffffffff8249d790,ffffffff82453283,90,ffffffff8240b983) at __assert+0x25 sys/kern/subr_prf.c:161 uvm_pagealloc_pg(fffffd8006448800,fffffd8072f2b890,466f32000,0) at uvm_pagealloc_pg+0x427 uvm_pageinsert sys/uvm/uvm_page.c:138 [inline] uvm_pagealloc_pg(fffffd8006448800,fffffd8072f2b890,466f32000,0) at uvm_pagealloc_pg+0x427 sys/uvm/uvm_page.c:710 uvm_pagealloc(fffffd8072f2b890,466f32000,0,3) at uvm_pagealloc+0x1e8 sys/uvm/uvm_page.c:918 pmap_get_ptp(fffffd8072f2b880,8cde651d000) at pmap_get_ptp+0x18d sys/arch/amd64/amd64/pmap.c:1183 pmap_enter(fffffd8072f2b880,8cde651d000,6d47a000,1,20) at pmap_enter+0x292 sys/arch/amd64/amd64/pmap.c:2697 uvm_fault_upper_lookup(ffff800027f554f0,ffff800027f55528,ffff800027f553f0,ffff800027f55470) at uvm_fault_upper_lookup+0x291 sys/uvm/uvm_fault.c:887 uvm_fault(fffffd806aea4230,8cde6520000,0,1) at uvm_fault+0x119 sys/uvm/uvm_fault.c:607 upageflttrap(ffff800027f55660,8cde6520028) at upageflttrap+0x79 sys/arch/amd64/amd64/trap.c:181 usertrap(ffff800027f55660) at usertrap+0x198 sys/arch/amd64/amd64/trap.c:403 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x8cd88810fe0, count: -12 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800027f55010 rbx 0 rdx 0xffff800000b3e580 rcx 0 rax 0xffff8000ffff9268 r8 0x101010101010101 r9 0x8080808080808080 r10 0xb405c5471e2dcf33 r11 0x5abf123cc7597e56 r12 0 r13 0x466f32000 r14 0 r15 0x1 rip 0xffffffff817dbb78 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800027f55000 ss 0 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (syz-executor.1) pid=209670 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffff8d28,0xffffffff82898858 process=0xffff800021670fb8 user=0xffff800027f50000, vmspace=0xfffffd806aea4230 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 50320 379721 31487 0 2 0 syz-executor.1 *50320 209670 31487 0 7 0x4000000 syz-executor.1 53061 437804 23602 0 3 0x2 biowait syz-executor.0 151 522873 23602 0 3 0x2 getblk syz-executor.3 68632 348711 1 0 3 0x100083 ttyin getty 1207 485044 23602 0 3 0x2 biowait syz-executor.2 38266 220510 0 0 3 0x14200 bored sosplice 31487 171878 23602 0 3 0x82 nanoslp syz-executor.1 23602 520475 67135 0 3 0x82 thrsleep syz-fuzzer 23602 11064 67135 0 3 0x4000082 nanoslp syz-fuzzer 23602 208192 67135 0 3 0x4000082 thrsleep syz-fuzzer 23602 88715 67135 0 3 0x4000082 thrsleep syz-fuzzer 23602 289658 67135 0 3 0x4000082 thrsleep syz-fuzzer 23602 48634 67135 0 3 0x4000082 kqread syz-fuzzer 23602 203150 67135 0 3 0x4000082 thrsleep syz-fuzzer 67135 133630 90833 0 3 0x10008a sigsusp ksh 90833 45523 70656 0 3 0x9a poll sshd 70656 230352 1 0 3 0x88 poll sshd 42422 439942 61831 73 3 0x100090 kqread syslogd 61831 251044 1 0 3 0x100082 netio syslogd 62112 99961 1 0 3 0x100080 kqread resolvd 64108 91102 81762 77 3 0x100092 kqread dhcpleased 66831 458972 81762 77 3 0x100092 kqread dhcpleased 81762 330635 1 0 3 0x80 kqread dhcpleased 81966 232749 0 0 3 0x14200 bored smr 99688 102855 0 0 2 0x14200 zerothread 80973 280828 0 0 3 0x14200 aiodoned aiodoned 59447 79646 0 0 3 0x14200 syncer update 1954 296626 0 0 3 0x14200 cleaner cleaner 20053 90545 0 0 3 0x14200 reaper reaper 69631 216305 0 0 3 0x14200 pgdaemon pagedaemon 88753 164471 0 0 3 0x14200 bored viomb 14570 171136 0 0 3 0x40014200 acpi0 acpi0 81534 81044 0 0 3 0x14200 bored softnet 50654 98391 0 0 3 0x14200 bored systqmp 10850 509711 0 0 3 0x14200 bored systq 53587 216329 0 0 3 0x40014200 bored softclock 72217 452846 0 0 3 0x40014200 idle0 1 507537 0 0 3 0x82 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 10178 6399K 6946K 78643K 15085 0 pcb 13 16K 18K 78643K 4647 0 rtable 190 16K 19K 78643K 12404 0 ifaddr 77 18K 18K 78643K 5157 0 sysctl 2 0K 0K 78643K 2 0 counters 24 17K 17K 78643K 55 0 ioctlops 0 0K 4K 78643K 7000 0 iov 0 0K 16K 78643K 2423 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1428 90K 90K 78643K 3510 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 29 0 VM map 2 0K 0K 78643K 2 0 sem 12 0K 0K 78643K 1190 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12598 0 file desc 7 21K 41K 78643K 9918 0 sigio 0 0K 0K 78643K 318 0 proc 61 55K 71K 78643K 1153 0 subproc 52 3K 3K 78643K 351 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 290 0 in_multi 52 3K 3K 78643K 524 0 ether_multi 1 0K 0K 78643K 34 0 mrt 1 0K 0K 78643K 13 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 235 1049K 1049K 78643K 235 0 exec 0 0K 2K 78643K 2694 0 tdb 3 0K 0K 78643K 3 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 7 26K 26K 78643K 7 0 UVM amap 243 98K 130K 78643K 118004 0 UVM aobj 121 7K 7K 78643K 142 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 185 0 NDP 8 0K 1K 78643K 129 0 temp 97 4197K 4261K 78643K 48317 0 kqueue 10 14K 18K 78643K 133 0 SYN cache 2 16K 16K 78643K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 533 0 530 10 9 1 3 0 8 0 rtentry 112 388 0 328 2 0 2 2 0 8 0 unpcb 136 2216 0 2203 31 30 1 9 0 8 0 syncache 296 10 0 10 3 3 0 1 0 8 0 sackhl 24 2 0 2 2 2 0 1 0 8 0 tcpqe 32 87 0 87 1 1 0 1 0 8 0 tcpcb 736 10388 0 10381 221 214 7 37 0 8 6 arp 88 58 0 48 1 0 1 1 0 8 0 ipq 40 22 0 22 7 7 0 1 0 8 0 ipqe 40 354 0 354 7 7 0 1 0 8 0 inpcb 304 22973 0 22966 161 158 3 16 0 8 2 rttmr 72 6 0 6 2 2 0 1 0 8 0 ip6q 72 36 0 36 1 1 0 1 0 8 0 ip6af 40 71 0 71 1 1 0 1 0 8 0 nd6 48 119 0 106 1 0 1 1 0 8 0 pkpcb 40 4 0 4 1 1 0 1 0 8 0 kcovpl 48 27 0 23 1 0 1 1 0 8 0 ppxss 1152 3 0 2 1 0 1 1 0 8 0 pfstscr 40 4 0 3 1 0 1 1 0 8 0 pfrktable 1344 5612 0 5588 6 3 3 3 0 8 0 pftag 88 43 0 35 2 1 1 1 0 8 0 pfqueue 264 4 0 4 1 1 0 1 0 8 0 pfstitem 24 2 0 0 1 0 1 1 0 8 0 pfstkey 112 8 0 6 1 0 1 1 0 8 0 pfstate 320 4 0 3 1 0 1 1 0 8 0 pfrule 1360 2355 0 2216 14 2 12 12 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 1636 0 1392 27 9 18 19 0 8 0 art_table 32 1637 0 1392 3 0 3 3 0 8 0 art_node 16 384 0 334 1 0 1 1 0 8 0 sysvmsgpl 40 19 0 0 1 0 1 1 0 8 0 semapl 112 1188 0 1178 1 0 1 1 0 8 0 shmpl 112 139 0 21 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 14540 0 13126 89 0 89 89 0 8 0 ffsino 240 14540 0 13126 84 0 84 84 0 8 0 nchpl 144 31409 0 29819 61 0 61 61 0 8 0 uvmvnodes 80 5926 0 0 121 0 121 121 0 8 0 vnodes 224 5926 0 0 349 0 349 349 0 8 0 namei 1024 82819 0 82818 6 5 1 1 0 8 0 vcpupl 1984 7 0 2 1 0 1 1 0 8 0 vmpool 528 18 0 13 2 1 1 1 0 8 0 pfiaddrpl 120 7877 0 7813 6 3 3 3 0 8 1 scxspl 216 79931 0 79929 10 9 1 8 0 8 0 plimitpl 152 250 0 240 1 0 1 1 0 8 0 sigapl 424 10073 0 10041 5 1 4 5 0 8 0 futexpl 64 124811 0 124811 8 7 1 1 0 8 1 knotepl 112 1501 0 1451 2 0 2 2 0 8 0 kqueuepl 184 613 0 607 11 10 1 5 0 8 0 pipepl 304 1234 0 1218 27 25 2 7 0 8 0 fdescpl 432 10059 0 10041 4 1 3 3 0 8 0 filepl 120 65195 0 65049 76 70 6 12 0 8 1 lockfpl 104 1548 0 1546 5 4 1 2 0 8 0 lockfspl 48 334 0 332 1 0 1 1 0 8 0 sessionpl 144 44 0 32 1 0 1 1 0 8 0 pgrppl 48 44 0 32 1 0 1 1 0 8 0 ucredpl 96 3633 0 3623 1 0 1 1 0 8 0 zombiepl 144 10041 0 10041 2 1 1 1 0 8 1 processpl 1000 10073 0 10041 5 0 5 5 0 8 0 procpl 672 22593 0 22554 24 19 5 6 0 8 1 sosppl 168 12 0 12 4 4 0 1 0 8 0 sockpl 448 25726 0 25703 330 323 7 30 0 8 4 mcl64k 65536 2034 0 2034 10 9 1 1 0 8 1 mcl16k 16384 55 0 55 10 10 0 1 0 8 0 mcl12k 12288 130 0 130 18 18 0 1 0 8 0 mcl9k 9216 47 0 47 17 17 0 1 0 8 0 mcl8k 8192 325 0 325 17 17 0 1 0 8 0 mcl4k 4096 872 0 872 17 16 1 1 0 8 1 mcl2k2 2112 87 0 87 13 13 0 1 0 8 0 mcl2k 2048 104569 0 104523 29 22 7 13 0 8 0 mtagpl 96 401 0 397 7 6 1 6 0 8 0 mbufpl 256 250210 0 250013 99 83 16 46 0 8 0 bufpl 288 15173 0 8756 459 0 459 459 0 8 0 anonpl 24 2611709 0 2594041 212 93 119 140 0 188 0 amapchunkpl 152 295740 0 295147 71 44 27 38 0 158 0 amappl16 200 23753 0 23073 85 47 38 49 0 8 0 amappl15 192 80 0 80 3 3 0 1 0 8 0 amappl14 184 1394 0 1391 1 0 1 1 0 8 0 amappl13 176 3788 0 3784 1 0 1 1 0 8 0 amappl12 168 2088 0 2082 1 0 1 1 0 8 0 amappl11 160 319 0 308 1 0 1 1 0 8 0 amappl10 152 331 0 323 1 0 1 1 0 8 0 amappl9 144 2370 0 2367 1 0 1 1 0 8 0 amappl8 136 834 0 786 2 0 2 2 0 8 0 amappl7 128 237 0 228 1 0 1 1 0 8 0 amappl6 120 2177 0 2163 1 0 1 1 0 8 0 amappl5 112 6099 0 6085 1 0 1 1 0 8 0 amappl4 104 1732 0 1711 1 0 1 1 0 8 0 amappl3 96 6084 0 6065 1 0 1 1 0 8 0 amappl2 88 6363 0 6322 2 0 2 2 0 8 0 amappl1 80 172670 0 172236 19 8 11 12 0 8 0 amappl 88 117262 0 117105 5 0 5 5 0 92 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 6 0 6 1 1 0 1 0 8 0 dma128 128 253 0 253 1 1 0 1 0 8 0 dma64 64 6 0 6 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 72 141 0 21 3 0 3 3 0 8 0 uaddrrnd 24 10077 0 10054 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 10077 0 10054 1 0 1 1 0 8 0 vmmpekpl 168 59364 0 59334 2 0 2 2 0 8 0 vmmpepl 168 895426 0 893474 217 120 97 121 0 357 3 vmsppl 272 10076 0 10054 3 1 2 2 0 8 0 rwobjpl 24 203883 0 196396 48 2 46 47 0 8 0 pdppl 4096 20160 0 20113 121 68 53 55 0 8 6 pvpl 32 4490962 0 4469768 352 166 186 242 0 265 0 pmappl 216 10076 0 10054 3 1 2 2 0 8 0 extentpl 40 57 0 38 1 0 1 1 0 8 0 phpool 112 1543 0 781 24 1 23 23 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff8242cc29) at panic+0x161 sys/kern/subr_prf.c:202 __assert(ffffffff8249d790,ffffffff82453283,90,ffffffff8240b983) at __assert+0x25 sys/kern/subr_prf.c:161 uvm_pagealloc_pg(fffffd8006448800,fffffd8072f2b890,466f32000,0) at uvm_pagealloc_pg+0x427 uvm_pageinsert sys/uvm/uvm_page.c:138 [inline] uvm_pagealloc_pg(fffffd8006448800,fffffd8072f2b890,466f32000,0) at uvm_pagealloc_pg+0x427 sys/uvm/uvm_page.c:710 uvm_pagealloc(fffffd8072f2b890,466f32000,0,3) at uvm_pagealloc+0x1e8 sys/uvm/uvm_page.c:918 pmap_get_ptp(fffffd8072f2b880,8cde651d000) at pmap_get_ptp+0x18d sys/arch/amd64/amd64/pmap.c:1183 pmap_enter(fffffd8072f2b880,8cde651d000,6d47a000,1,20) at pmap_enter+0x292 sys/arch/amd64/amd64/pmap.c:2697 uvm_fault_upper_lookup(ffff800027f554f0,ffff800027f55528,ffff800027f553f0,ffff800027f55470) at uvm_fault_upper_lookup+0x291 sys/uvm/uvm_fault.c:887 uvm_fault(fffffd806aea4230,8cde6520000,0,1) at uvm_fault+0x119 sys/uvm/uvm_fault.c:607 upageflttrap(ffff800027f55660,8cde6520028) at upageflttrap+0x79 sys/arch/amd64/amd64/trap.c:181 usertrap(ffff800027f55660) at usertrap+0x198 sys/arch/amd64/amd64/trap.c:403 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x8cd88810fe0, count: -12 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff8242cc29) at panic+0x161 sys/kern/subr_prf.c:202 __assert(ffffffff8249d790,ffffffff82453283,90,ffffffff8240b983) at __assert+0x25 sys/kern/subr_prf.c:161 uvm_pagealloc_pg(fffffd8006448800,fffffd8072f2b890,466f32000,0) at uvm_pagealloc_pg+0x427 uvm_pageinsert sys/uvm/uvm_page.c:138 [inline] uvm_pagealloc_pg(fffffd8006448800,fffffd8072f2b890,466f32000,0) at uvm_pagealloc_pg+0x427 sys/uvm/uvm_page.c:710 uvm_pagealloc(fffffd8072f2b890,466f32000,0,3) at uvm_pagealloc+0x1e8 sys/uvm/uvm_page.c:918 pmap_get_ptp(fffffd8072f2b880,8cde651d000) at pmap_get_ptp+0x18d sys/arch/amd64/amd64/pmap.c:1183 pmap_enter(fffffd8072f2b880,8cde651d000,6d47a000,1,20) at pmap_enter+0x292 sys/arch/amd64/amd64/pmap.c:2697 uvm_fault_upper_lookup(ffff800027f554f0,ffff800027f55528,ffff800027f553f0,ffff800027f55470) at uvm_fault_upper_lookup+0x291 sys/uvm/uvm_fault.c:887 uvm_fault(fffffd806aea4230,8cde6520000,0,1) at uvm_fault+0x119 sys/uvm/uvm_fault.c:607 upageflttrap(ffff800027f55660,8cde6520028) at upageflttrap+0x79 sys/arch/amd64/amd64/trap.c:181 usertrap(ffff800027f55660) at usertrap+0x198 sys/arch/amd64/amd64/trap.c:403 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x8cd88810fe0, count: -12