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 * 94107 1917 0 0 0 0 syz-executor.2 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8257048f) at panic+0x161 sys/kern/subr_prf.c:202 __assert(ffffffff825e3578,ffffffff825931f0,90,ffffffff82547011) at __assert+0x25 sys/kern/subr_prf.c:161 uvm_pagealloc_pg(fffffd80066f6b00,fffffd8077c8a030,d975000,0) at uvm_pagealloc_pg+0x427 uvm_pageinsert sys/uvm/uvm_page.c:138 [inline] uvm_pagealloc_pg(fffffd80066f6b00,fffffd8077c8a030,d975000,0) at uvm_pagealloc_pg+0x427 sys/uvm/uvm_page.c:709 uvm_pagealloc(fffffd8077c8a030,d975000,0,3) at uvm_pagealloc+0x1e8 sys/uvm/uvm_page.c:917 pmap_get_ptp(fffffd8077c8a020,1b2ea21000) at pmap_get_ptp+0x18d sys/arch/amd64/amd64/pmap.c:1183 pmap_enter(fffffd8077c8a020,1b2ea21000,68463000,3,20) at pmap_enter+0x2a0 uvm_fault_lower_lookup(ffff80002998ba30,ffff80002998ba68,ffff80002998b9b0) at uvm_fault_lower_lookup+0x263 sys/uvm/uvm_fault.c:1183 uvm_fault_lower(ffff80002998ba30,ffff80002998ba68,ffff80002998b9b0,0) at uvm_fault_lower+0x5f sys/uvm/uvm_fault.c:1218 uvm_fault(fffffd807f016770,1b2ea20000,0,2) at uvm_fault+0x21d upageflttrap(ffff80002998bba0,1b2ea20218) at upageflttrap+0x79 sys/arch/amd64/amd64/trap.c:181 usertrap(ffff80002998bba0) at usertrap+0x198 sys/arch/amd64/amd64/trap.c:403 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x7f7fffff5500, count: 2 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:437 panic(ffffffff8257048f) at panic+0x161 sys/kern/subr_prf.c:202 __assert(ffffffff825e3578,ffffffff825931f0,90,ffffffff82547011) at __assert+0x25 sys/kern/subr_prf.c:161 uvm_pagealloc_pg(fffffd80066f6b00,fffffd8077c8a030,d975000,0) at uvm_pagealloc_pg+0x427 uvm_pageinsert sys/uvm/uvm_page.c:138 [inline] uvm_pagealloc_pg(fffffd80066f6b00,fffffd8077c8a030,d975000,0) at uvm_pagealloc_pg+0x427 sys/uvm/uvm_page.c:709 uvm_pagealloc(fffffd8077c8a030,d975000,0,3) at uvm_pagealloc+0x1e8 sys/uvm/uvm_page.c:917 pmap_get_ptp(fffffd8077c8a020,1b2ea21000) at pmap_get_ptp+0x18d sys/arch/amd64/amd64/pmap.c:1183 pmap_enter(fffffd8077c8a020,1b2ea21000,68463000,3,20) at pmap_enter+0x2a0 uvm_fault_lower_lookup(ffff80002998ba30,ffff80002998ba68,ffff80002998b9b0) at uvm_fault_lower_lookup+0x263 sys/uvm/uvm_fault.c:1183 uvm_fault_lower(ffff80002998ba30,ffff80002998ba68,ffff80002998b9b0,0) at uvm_fault_lower+0x5f sys/uvm/uvm_fault.c:1218 uvm_fault(fffffd807f016770,1b2ea20000,0,2) at uvm_fault+0x21d upageflttrap(ffff80002998bba0,1b2ea20218) at upageflttrap+0x79 sys/arch/amd64/amd64/trap.c:181 usertrap(ffff80002998bba0) at usertrap+0x198 sys/arch/amd64/amd64/trap.c:403 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x7f7fffff5500, count: -13 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002998b4b0 rbx 0 rdx 0 rcx 0 rax 0xffff800029961cf0 r8 0x101010101010101 r9 0x8080808080808080 r10 0xbf72a3ad623c462b r11 0xb498905c3e476352 r12 0 r13 0xd975000 __kernel_phys_end+0xad75000 r14 0 r15 0x1 rip 0xffffffff821edcc8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002998b4a0 ss 0 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (syz-executor.2) pid=94107 stat=onproc flags process=0 proc=0 pri=32, usrpri=81, nice=20 forw=0xffffffffffffffff, list=0xffff8000215fca80,0xffff800021609270 process=0xffff800021687798 user=0xffff800029986000, vmspace=0xfffffd807f016770 estcpu=31, cpticks=5, pctcpu=0.2 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 51019 141698 23873 0 2 0x480 syz-executor.3 51019 23083 23873 0 3 0x4000080 fsleep syz-executor.3 * 1917 94107 85166 0 7 0 syz-executor.2 1917 171809 85166 0 3 0x4000080 fsleep syz-executor.2 1917 148859 85166 0 3 0x4000080 fsleep syz-executor.2 1917 471709 85166 0 3 0x4000080 fsleep syz-executor.2 71316 434276 18180 0 3 0x82 piperd syz-executor.1 12301 192442 18180 0 2 0x2 syz-executor.5 95849 435758 18180 0 2 0x2 syz-executor.6 23873 75672 18180 0 3 0x82 nanoslp syz-executor.3 71662 349977 18180 0 3 0x82 piperd syz-executor.7 92690 14110 0 0 3 0x14200 bored sosplice 36960 460898 18180 0 2 0x2 syz-executor.4 85166 252225 18180 0 3 0x82 nanoslp syz-executor.2 51502 208346 18180 0 2 0x2 syz-executor.0 18180 104496 36334 0 3 0x82 thrsleep syz-fuzzer 18180 194952 36334 0 3 0x4000082 thrsleep syz-fuzzer 18180 296278 36334 0 3 0x4000082 thrsleep syz-fuzzer 18180 110808 36334 0 3 0x4000082 kqread syz-fuzzer 18180 348445 36334 0 3 0x4000082 thrsleep syz-fuzzer 18180 178345 36334 0 3 0x4000082 thrsleep syz-fuzzer 18180 123758 36334 0 3 0x4000082 thrsleep syz-fuzzer 18180 267748 36334 0 3 0x4000082 thrsleep syz-fuzzer 18180 219024 36334 0 3 0x4000082 thrsleep syz-fuzzer 36334 388193 62216 0 3 0x10008a sigsusp ksh 62216 286295 99584 0 3 0x9a kqread sshd 88044 318302 1 0 3 0x100083 ttyin getty 99584 25878 1 0 3 0x88 kqread sshd 99228 459313 16867 73 3 0x1100090 kqread syslogd 16867 406693 1 0 3 0x100082 netio syslogd 93168 488700 1 0 3 0x100080 kqread resolvd 99037 501332 19098 77 3 0x100092 kqread dhcpleased 30069 447042 19098 77 3 0x100092 kqread dhcpleased 19098 313197 1 0 3 0x80 kqread dhcpleased 59681 45922 0 0 3 0x14200 bored smr 42110 12610 0 0 3 0x14200 pgzero zerothread 10248 147893 0 0 3 0x14200 aiodoned aiodoned 86872 64254 0 0 3 0x14200 syncer update 13921 83013 0 0 3 0x14200 cleaner cleaner 5067 24016 0 0 3 0x14200 reaper reaper 38338 146736 0 0 3 0x14200 pgdaemon pagedaemon 52624 111544 0 0 3 0x14200 bored viomb 57943 228720 0 0 3 0x40014200 acpi0 acpi0 35368 334741 0 0 3 0x14200 bored softnet 62823 523415 0 0 3 0x14200 bored softnet 10132 285410 0 0 3 0x14200 bored softnet 92770 287541 0 0 3 0x14200 bored softnet 704 49563 0 0 3 0x14200 bored systqmp 53845 341893 0 0 3 0x14200 bored systq 51411 234629 0 0 3 0x40014200 bored softclock 5299 40433 0 0 3 0x40014200 idle0 1 34456 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 6491K 6927K 78643K 16286 0 pcb 13 11K 12K 78643K 290 0 rtable 165 13K 15K 78643K 680 0 ifaddr 76 15K 18K 78643K 217 0 counters 26 17K 17K 78643K 44 0 ioctlops 0 0K 4K 78643K 1038 0 iov 0 0K 32K 78643K 135 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 5 0 vnodes 1339 84K 84K 78643K 2480 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 10 0 VM map 2 0K 0K 78643K 2 0 sem 11 1K 1K 78643K 19 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 12 41K 85K 78643K 3876 0 sigio 0 0K 0K 78643K 44 0 proc 58 59K 83K 78643K 750 0 subproc 104 6K 6K 78643K 195 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 119 0 in_multi 69 4K 6K 78643K 225 0 ether_multi 1 0K 0K 78643K 19 0 mrt 1 0K 0K 78643K 30 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 61 281K 281K 78643K 61 0 exec 0 0K 2K 78643K 1085 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 262 309K 359K 78643K 20291 0 UVM aobj 14 2K 2K 78643K 14 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 116 0 NDP 11 0K 2K 78643K 60 0 temp 131 4740K 4816K 78643K 23273 0 kqueue 12 18K 24K 78643K 141 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 120 172 0 169 1 0 1 1 0 8 0 rtentry 112 201 0 133 4 1 3 4 0 8 0 unpcb 136 1623 0 1610 13 12 1 7 0 8 0 syncache 296 35 0 35 5 4 1 1 0 8 1 tcpqe 32 6 0 6 2 2 0 1 0 8 0 tcpcb 736 970 0 966 31 29 2 14 0 8 1 arp 88 32 0 20 1 0 1 1 0 8 0 inpcb 312 2063 0 2056 24 22 2 11 0 8 1 nd6 48 46 0 30 1 0 1 1 0 8 0 pkpcb 40 13 0 13 4 4 0 1 0 8 0 kcovpl 48 15 0 7 1 0 1 1 0 8 0 pfrktable 1344 1 0 1 1 1 0 1 0 8 0 pftag 88 8 0 7 2 1 1 1 0 8 0 pfqueue 264 3 0 3 1 1 0 1 0 8 0 pfstkey 112 8 0 8 1 1 0 1 0 8 0 pfstate 336 4 0 4 1 1 0 1 0 8 0 pfrule 1360 40 0 39 2 1 1 1 0 8 0 rttmr 64 7 0 7 2 2 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 855 0 524 32 9 23 29 0 8 0 art_table 32 856 0 524 4 0 4 4 0 8 0 art_node 16 200 0 139 1 0 1 1 0 8 0 sysvmsgpl 40 46 0 29 1 0 1 1 0 8 0 semupl 112 8 0 8 1 1 0 1 0 8 0 semapl 112 9 0 0 1 0 1 1 0 8 0 shmpl 112 11 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 5854 0 4423 90 0 90 90 0 8 0 ffsino 240 5854 0 4423 85 0 85 85 0 8 0 nchpl 144 10475 0 8836 63 0 63 63 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 30048 0 30048 5 4 1 2 0 8 1 vcpupl 1984 17 0 3 3 1 2 3 0 8 0 vmpool 528 21 0 7 3 1 2 2 0 8 0 kstatmem 264 58 0 36 2 0 2 2 0 8 0 scxspl 216 31218 0 31218 14 13 1 8 0 8 1 plimitpl 152 126 0 112 1 0 1 1 0 8 0 sigapl 424 4141 0 4101 7 1 6 6 0 8 0 futexpl 64 24739 0 24735 4 3 1 1 0 8 0 knotepl 120 41976 0 41896 22 18 4 15 0 8 0 kqueuepl 184 477 0 469 4 3 1 4 0 8 0 pipepl 304 295 0 267 3 0 3 3 0 8 0 fdescpl 432 4124 0 4101 5 1 4 4 0 8 0 filepl 120 15286 0 15042 30 20 10 15 0 8 2 lockfpl 104 439 0 434 1 0 1 1 0 8 0 lockfspl 48 138 0 134 1 0 1 1 0 8 0 sessionpl 144 30 0 14 1 0 1 1 0 8 0 pgrppl 48 30 0 14 1 0 1 1 0 8 0 ucredpl 96 1303 0 1292 1 0 1 1 0 8 0 zombiepl 144 4101 0 4101 4 3 1 1 0 8 1 processpl 1000 4141 0 4101 7 1 6 7 0 8 0 procpl 672 8407 0 8355 7 1 6 6 0 8 0 sosppl 168 43 0 43 5 5 0 1 0 8 0 sockpl 448 3872 0 3849 70 65 5 30 0 8 2 mcl64k 65536 68 0 68 6 6 0 1 0 8 0 mcl16k 16384 30 0 30 4 4 0 1 0 8 0 mcl12k 12288 35 0 35 4 4 0 1 0 8 0 mcl9k 9216 6 0 6 2 2 0 1 0 8 0 mcl8k 8192 45 0 45 8 7 1 1 0 8 1 mcl4k 4096 205 0 205 9 8 1 1 0 8 1 mcl2k2 2112 1 0 1 1 1 0 1 0 8 0 mcl2k 2048 30763 0 30699 49 38 11 17 0 8 0 mtagpl 96 952 0 324 17 1 16 16 0 8 0 mbufpl 256 84550 0 83679 85 28 57 62 0 8 1 bufpl 288 8983 0 2582 458 0 458 458 0 8 0 anonpl 24 746264 0 736751 162 73 89 100 0 188 0 amapchunkpl 152 58814 0 58369 45 25 20 38 0 158 0 amappl16 200 11738 0 11464 88 72 16 37 0 8 0 amappl15 192 1446 0 1442 1 0 1 1 0 8 0 amappl14 184 264 0 260 1 0 1 1 0 8 0 amappl13 176 586 0 585 1 0 1 1 0 8 0 amappl12 168 648 0 644 1 0 1 1 0 8 0 amappl11 160 95 0 79 1 0 1 1 0 8 0 amappl10 152 257 0 255 1 0 1 1 0 8 0 amappl9 144 748 0 741 1 0 1 1 0 8 0 amappl8 136 1349 0 1280 3 0 3 3 0 8 0 amappl7 128 796 0 784 1 0 1 1 0 8 0 amappl6 120 481 0 461 2 1 1 2 0 8 0 amappl5 112 3536 0 3519 1 0 1 1 0 8 0 amappl4 104 1220 0 1192 2 1 1 2 0 8 0 amappl3 96 11084 0 11047 4 2 2 2 0 8 0 amappl2 88 5099 0 5042 3 1 2 3 0 8 0 amappl1 80 93793 0 93240 22 8 14 19 0 8 0 amappl 88 19637 0 19494 4 0 4 4 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 13 0 0 1 0 1 1 0 8 0 uaddrrnd 24 4145 0 4108 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4145 0 4108 1 0 1 1 0 8 0 vmmpekpl 168 25795 0 25754 3 0 3 3 0 8 0 vmmpepl 168 384112 0 382222 131 26 105 110 0 357 3 vmsppl 272 4144 0 4108 5 2 3 4 0 8 0 rwobjpl 24 95195 0 88050 46 2 44 44 0 8 0 pdppl 4096 8296 0 8230 259 183 76 82 0 8 10 pvpl 32 1575526 0 1562113 270 130 140 240 0 265 0 pmappl 216 4144 0 4108 5 2 3 3 0 8 0 extentpl 40 58 0 38 1 0 1 1 0 8 0 phpool 112 1230 0 409 25 0 25 25 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:437 panic(ffffffff8257048f) at panic+0x161 sys/kern/subr_prf.c:202 __assert(ffffffff825e3578,ffffffff825931f0,90,ffffffff82547011) at __assert+0x25 sys/kern/subr_prf.c:161 uvm_pagealloc_pg(fffffd80066f6b00,fffffd8077c8a030,d975000,0) at uvm_pagealloc_pg+0x427 uvm_pageinsert sys/uvm/uvm_page.c:138 [inline] uvm_pagealloc_pg(fffffd80066f6b00,fffffd8077c8a030,d975000,0) at uvm_pagealloc_pg+0x427 sys/uvm/uvm_page.c:709 uvm_pagealloc(fffffd8077c8a030,d975000,0,3) at uvm_pagealloc+0x1e8 sys/uvm/uvm_page.c:917 pmap_get_ptp(fffffd8077c8a020,1b2ea21000) at pmap_get_ptp+0x18d sys/arch/amd64/amd64/pmap.c:1183 pmap_enter(fffffd8077c8a020,1b2ea21000,68463000,3,20) at pmap_enter+0x2a0 uvm_fault_lower_lookup(ffff80002998ba30,ffff80002998ba68,ffff80002998b9b0) at uvm_fault_lower_lookup+0x263 sys/uvm/uvm_fault.c:1183 uvm_fault_lower(ffff80002998ba30,ffff80002998ba68,ffff80002998b9b0,0) at uvm_fault_lower+0x5f sys/uvm/uvm_fault.c:1218 uvm_fault(fffffd807f016770,1b2ea20000,0,2) at uvm_fault+0x21d upageflttrap(ffff80002998bba0,1b2ea20218) at upageflttrap+0x79 sys/arch/amd64/amd64/trap.c:181 usertrap(ffff80002998bba0) at usertrap+0x198 sys/arch/amd64/amd64/trap.c:403 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x7f7fffff5500, count: -13 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8257048f) at panic+0x161 sys/kern/subr_prf.c:202 __assert(ffffffff825e3578,ffffffff825931f0,90,ffffffff82547011) at __assert+0x25 sys/kern/subr_prf.c:161 uvm_pagealloc_pg(fffffd80066f6b00,fffffd8077c8a030,d975000,0) at uvm_pagealloc_pg+0x427 uvm_pageinsert sys/uvm/uvm_page.c:138 [inline] uvm_pagealloc_pg(fffffd80066f6b00,fffffd8077c8a030,d975000,0) at uvm_pagealloc_pg+0x427 sys/uvm/uvm_page.c:709 uvm_pagealloc(fffffd8077c8a030,d975000,0,3) at uvm_pagealloc+0x1e8 sys/uvm/uvm_page.c:917 pmap_get_ptp(fffffd8077c8a020,1b2ea21000) at pmap_get_ptp+0x18d sys/arch/amd64/amd64/pmap.c:1183 pmap_enter(fffffd8077c8a020,1b2ea21000,68463000,3,20) at pmap_enter+0x2a0 uvm_fault_lower_lookup(ffff80002998ba30,ffff80002998ba68,ffff80002998b9b0) at uvm_fault_lower_lookup+0x263 sys/uvm/uvm_fault.c:1183 uvm_fault_lower(ffff80002998ba30,ffff80002998ba68,ffff80002998b9b0,0) at uvm_fault_lower+0x5f sys/uvm/uvm_fault.c:1218 uvm_fault(fffffd807f016770,1b2ea20000,0,2) at uvm_fault+0x21d upageflttrap(ffff80002998bba0,1b2ea20218) at upageflttrap+0x79 sys/arch/amd64/amd64/trap.c:181 usertrap(ffff80002998bba0) at usertrap+0x198 sys/arch/amd64/amd64/trap.c:403 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x7f7fffff5500, count: -13