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 *437263 24749 0 0x2 0 0K syz-executor.1 159600 47539 0 0x2 0x4000000 1 syz-fuzzer 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(fffffd807a9423d8,1d8f5d000,0,3) at uvm_pagealloc+0x476 sys/uvm/uvm_page.c:140 pmap_get_ptp(fffffd807a9423a8,3b1eba07000) at pmap_get_ptp+0xe8 sys/arch/amd64/amd64/pmap.c:1103 pmap_enter(fffffd807a9423a8,3b1eba07000,66e56000,3,20) at pmap_enter+0x2a8 uvm_fault(fffffd807f00a450,3b1eba06000,0,2) at uvm_fault+0x77b sys/uvm/uvm_fault.c:691 pageflttrap() at pageflttrap+0x20b sys/arch/amd64/amd64/trap.c:199 usertrap(ffff800023981ac0) at usertrap+0x21a sys/arch/amd64/amd64/trap.c:369 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x7f7ffffc7cd0, count: 5 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{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic kernel diagnostic assertion "dupe == NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/uvm/uvm_page.c", line 140 ddb{0}> trace 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(fffffd807a9423d8,1d8f5d000,0,3) at uvm_pagealloc+0x476 sys/uvm/uvm_page.c:140 pmap_get_ptp(fffffd807a9423a8,3b1eba07000) at pmap_get_ptp+0xe8 sys/arch/amd64/amd64/pmap.c:1103 pmap_enter(fffffd807a9423a8,3b1eba07000,66e56000,3,20) at pmap_enter+0x2a8 uvm_fault(fffffd807f00a450,3b1eba06000,0,2) at uvm_fault+0x77b sys/uvm/uvm_fault.c:691 pageflttrap() at pageflttrap+0x20b sys/arch/amd64/amd64/trap.c:199 usertrap(ffff800023981ac0) at usertrap+0x21a sys/arch/amd64/amd64/trap.c:369 recall_trap() at recall_trap+0x8 end of kernel end trace frame: 0x7f7ffffc7cd0, count: -10 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff8000239814b0 rbx 0xffff800023981560 rdx 0xffff800020ab0790 rcx 0 rax 0 r8 0xffffffff815a9a5f kprintf+0x16f r9 0x1 r10 0x25 r11 0x821f90affc856ed6 r12 0x3000000008 r13 0xffff8000239814c0 r14 0x100 r15 0x1 rip 0xffffffff8169f578 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000239814a0 ss 0 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=437263 stat=onproc flags process=2 proc=0 pri=81, usrpri=81, nice=20 forw=0xffffffffffffffff, list=0xffff800020abf8c8,0xffff800020abeef8 process=0xffff800020a8b510 user=0xffff80002397c000, vmspace=0xfffffd807f00a450 estcpu=36, cpticks=1, pctcpu=0.9 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 34650 440509 40234 0 2 0 syz-executor.0 34650 322844 40234 0 3 0x4000080 piperd syz-executor.0 *24749 437263 47539 0 7 0x2 syz-executor.1 40234 106276 47539 0 3 0x82 nanosleep syz-executor.0 9892 516102 0 0 3 0x14200 acct acct 72420 304069 1 0 3 0x100083 ttyin getty 19244 115104 0 0 3 0x14200 bored sosplice 47539 99026 82000 0 3 0x82 thrsleep syz-fuzzer 47539 113171 82000 0 3 0x4000082 nanosleep syz-fuzzer 47539 139826 82000 0 3 0x4000082 thrsleep syz-fuzzer 47539 101577 82000 0 3 0x4000082 thrsleep syz-fuzzer 47539 45008 82000 0 3 0x4000082 thrsleep syz-fuzzer 47539 159600 82000 0 7 0x4000002 syz-fuzzer 47539 318283 82000 0 3 0x4000082 thrsleep syz-fuzzer 47539 9775 82000 0 3 0x4000082 thrsleep syz-fuzzer 47539 439579 82000 0 3 0x4000082 thrsleep syz-fuzzer 47539 366294 82000 0 3 0x4000082 thrsleep syz-fuzzer 82000 24502 92066 0 3 0x10008a pause ksh 92066 40344 86981 0 3 0x92 select sshd 86981 144822 1 0 3 0x80 select sshd 29974 115393 31496 74 3 0x100092 bpf pflogd 31496 183530 1 0 3 0x80 netio pflogd 55312 76735 41036 73 3 0x100090 kqread syslogd 41036 97492 1 0 3 0x100082 netio syslogd 84304 426530 1 77 3 0x100090 poll dhclient 94077 434206 1 0 3 0x80 poll dhclient 30705 249303 0 0 2 0x14200 zerothread 40090 321199 0 0 3 0x14200 aiodoned aiodoned 56195 366607 0 0 3 0x14200 syncer update 9175 252162 0 0 3 0x14200 cleaner cleaner 92669 284532 0 0 3 0x14200 reaper reaper 81000 116778 0 0 3 0x14200 pgdaemon pagedaemon 2652 3168 0 0 3 0x14200 bored crynlk 92151 426334 0 0 3 0x14200 bored crypto 35499 507497 0 0 3 0x40014200 acpi0 acpi0 54498 416207 0 0 3 0x40014200 idle1 89698 66199 0 0 3 0x14200 bored softnet 48803 497876 0 0 3 0x14200 bored systqmp 51076 130793 0 0 3 0x14200 bored systq 74809 381605 0 0 3 0x40014200 bored softclock 13791 189592 0 0 3 0x40014200 idle0 87552 297658 0 0 3 0x14200 bored smr 1 107332 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks CPU 0: exclusive mutex &pmap->pm_mtx r = 0 (0xfffffd807a9423b8) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 mtx_enter_try+0x102 #2 mtx_enter+0x4b sys/kern/kern_lock.c:266 #3 pmap_enter+0x1bc rcr3 machine/cpufunc.h:141 [inline] #3 pmap_enter+0x1bc pmap_map_ptes sys/arch/amd64/amd64/pmap.c:414 [inline] #3 pmap_enter+0x1bc sys/arch/amd64/amd64/pmap.c:2606 #4 uvm_fault+0x77b sys/uvm/uvm_fault.c:691 #5 pageflttrap+0x20b sys/arch/amd64/amd64/trap.c:199 #6 usertrap+0x21a sys/arch/amd64/amd64/trap.c:369 #7 recall_trap+0x8 Process 24749 (syz-executor.1) thread 0xffff800020ab0790 (437263) shared rwlock vmmaplk r = 0 (0xfffffd807f00a468) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 uvmfault_lookup+0xd9 sys/uvm/uvm_fault.c:1448 #2 uvm_fault+0xd85 sys/uvm/uvm_fault.c:524 #3 pageflttrap+0x20b sys/arch/amd64/amd64/trap.c:199 #4 usertrap+0x21a sys/arch/amd64/amd64/trap.c:369 #5 recall_trap+0x8 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8263a9c8) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 pageflttrap+0x6f sys/arch/amd64/amd64/trap.c:162 #2 usertrap+0x21a sys/arch/amd64/amd64/trap.c:369 #3 recall_trap+0x8 exclusive mutex &pmap->pm_mtx r = 0 (0xfffffd807a9423b8) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 mtx_enter_try+0x102 #2 mtx_enter+0x4b sys/kern/kern_lock.c:266 #3 pmap_enter+0x1bc rcr3 machine/cpufunc.h:141 [inline] #3 pmap_enter+0x1bc pmap_map_ptes sys/arch/amd64/amd64/pmap.c:414 [inline] #3 pmap_enter+0x1bc sys/arch/amd64/amd64/pmap.c:2606 #4 uvm_fault+0x77b sys/uvm/uvm_fault.c:691 #5 pageflttrap+0x20b sys/arch/amd64/amd64/trap.c:199 #6 usertrap+0x21a sys/arch/amd64/amd64/trap.c:369 #7 recall_trap+0x8 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9595 7078K 9598K 78643K 34361 0 0 pcb 13 10K 12K 78643K 1769 0 0 rtable 118 13K 14K 78643K 4366 0 0 ifaddr 383 42K 44K 78643K 1499 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1815 0 0 iov 1 1K 48K 78643K 2616 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1232 77K 78K 78643K 8990 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 9K 78643K 78 0 0 VM map 56 28K 28K 78643K 95 0 0 sem 12 0K 1K 78643K 1756 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 6862 0 0 sigio 0 0K 0K 78643K 144 0 0 proc 62 63K 95K 78643K 2836 0 0 subproc 32 2K 2K 78643K 680 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 1K 78643K 8259 0 0 in_multi 29 1K 2K 78643K 878 0 0 ether_multi 1 0K 0K 78643K 96 0 0 mrt 3 0K 0K 78643K 46 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 96 424K 424K 78643K 96 0 0 exec 0 0K 1K 78643K 1325 0 0 pfkey data 0 0K 4K 78643K 6 0 0 pagedep 1 8K 8K 78643K 1 0 0 inodedep 1 32K 32K 78643K 1 0 0 newblk 1 0K 0K 78643K 1 0 0 VM swap 7 26K 26K 78643K 7 0 0 UVM amap 257 510K 510K 78643K 26947 0 0 UVM aobj 130 6K 6K 78643K 138 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 1K 78643K 1624 0 0 NDP 24 0K 1K 78643K 385 0 0 temp 184 3556K 4196K 78643K 255637 0 0 kqueue 0 0K 0K 78643K 122 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 179 0 173 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 740 0 738 1 0 1 1 0 8 0 rtentry 112 742 0 701 2 0 2 2 0 8 0 unpcb 120 4969 0 4955 7 6 1 2 0 8 0 syncache 264 38 0 38 19 19 0 1 0 8 0 tcpqe 32 112 0 112 9 9 0 1 0 8 0 tcpcb 544 10323 0 10318 53 51 2 12 0 8 0 ipq 40 1 0 1 1 1 0 1 0 8 0 ipqe 40 2 0 2 1 1 0 1 0 8 0 inpcb 280 18231 0 18223 60 57 3 9 0 8 1 rttmr 72 13 0 12 2 1 1 1 0 8 0 ip6q 72 5 0 5 4 4 0 1 0 8 0 ip6af 40 13 0 13 4 4 0 1 0 8 0 nd6 48 97 0 94 7 6 1 1 0 8 0 pkpcb 40 39 0 39 16 15 1 1 0 8 1 swfcl 56 8 0 0 1 0 1 1 0 8 0 ppxss 1128 178 0 178 35 35 0 1 0 8 0 pffrag 232 202 0 202 36 35 1 1 0 482 1 pffrnode 88 201 0 201 36 35 1 1 0 8 1 pffrent 40 8120 0 8120 35 34 1 1 0 8 1 pfosfp 40 846 0 423 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 650 0 608 1 0 1 1 0 8 0 pfstkey 112 650 0 608 3 1 2 3 0 8 0 pfstate 328 650 0 608 11 6 5 7 0 8 1 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 30 0 28 16 14 2 4 0 8 0 art_heap4 256 3123 0 2849 39 21 18 20 0 8 0 art_table 32 3153 0 2877 7 4 3 3 0 8 0 art_node 16 741 0 704 1 0 1 1 0 8 0 sysvmsgpl 40 27 0 7 2 1 1 1 0 8 0 semupl 112 3 0 3 1 1 0 1 0 8 0 semapl 112 1754 0 1744 1 0 1 1 0 8 0 shmpl 112 136 0 8 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 11890 0 10442 47 0 47 47 0 8 0 ffsino 272 11890 0 10442 98 1 97 97 0 8 0 nchpl 144 23483 0 23000 61 40 21 61 0 8 0 uvmvnodes 72 6603 0 0 121 0 121 121 0 8 0 vnodes 208 6603 0 0 348 0 348 348 0 8 0 namei 1024 89715 0 89715 9 8 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 57 0 3 7 0 7 7 0 8 0 vmpool 552 93 0 39 6 2 4 4 0 8 0 scsiplug 64 9 0 9 7 7 0 1 0 8 0 scxspl 192 73332 0 73332 55 54 1 7 0 8 1 plimitpl 152 539 0 531 1 0 1 1 0 8 0 sigapl 432 6949 0 6934 4 2 2 3 0 8 0 futexpl 56 186993 0 186993 6 5 1 1 0 8 1 knotepl 112 1673 0 1654 9 8 1 3 0 8 0 kqueuepl 104 2440 0 2438 5 4 1 4 0 8 0 pipepl 160 7078 0 7057 21 19 2 3 0 8 1 fdescpl 488 6950 0 6934 3 0 3 3 0 8 0 filepl 152 76268 0 76164 82 76 6 14 0 8 2 lockfpl 104 2959 0 2958 1 0 1 1 0 8 0 lockfspl 48 922 0 921 1 0 1 1 0 8 0 sessionpl 112 59 0 48 1 0 1 1 0 8 0 pgrppl 48 137 0 126 1 0 1 1 0 8 0 ucredpl 96 7039 0 7030 1 0 1 1 0 8 0 zombiepl 144 6939 0 6939 10 9 1 1 0 8 1 processpl 896 6972 0 6939 5 1 4 5 0 8 0 procpl 632 23906 0 23863 6 1 5 5 0 8 0 srpgc 64 54 0 54 24 24 0 1 0 8 0 sosppl 128 244 0 244 35 35 0 1 0 8 0 sockpl 384 24117 0 24093 101 95 6 14 0 8 2 mcl64k 65536 618 0 0 69 52 17 35 0 8 1 mcl16k 16384 39 0 0 5 3 2 3 0 8 0 mcl12k 12288 49 0 0 2 0 2 2 0 8 0 mcl9k 9216 22 0 0 2 0 2 2 0 8 0 mcl8k 8192 33 0 0 4 1 3 3 0 8 0 mcl4k 4096 33 0 0 3 0 3 3 0 8 0 mcl2k2 2112 15 0 0 1 0 1 1 0 8 0 mcl2k 2048 355 0 0 21 11 10 21 0 8 0 mtagpl 80 441 0 0 3 1 2 3 0 8 0 mbufpl 256 1502 0 0 51 0 51 51 0 8 0 bufpl 256 26143 0 19085 442 0 442 442 0 8 0 anonpl 16 904411 0 881056 316 213 103 111 0 124 0 amapchunkpl 152 54329 0 54149 81 70 11 21 0 158 0 amappl16 192 40191 0 38849 328 259 69 80 0 8 0 amappl15 184 1149 0 1147 1 0 1 1 0 8 0 amappl14 176 2132 0 2126 1 0 1 1 0 8 0 amappl13 168 1292 0 1292 5 5 0 1 0 8 0 amappl12 160 593 0 591 1 0 1 1 0 8 0 amappl11 152 905 0 888 1 0 1 1 0 8 0 amappl10 144 173 0 166 1 0 1 1 0 8 0 amappl9 136 1840 0 1837 1 0 1 1 0 8 0 amappl8 128 1511 0 1433 4 1 3 3 0 8 0 amappl7 120 376 0 366 1 0 1 1 0 8 0 amappl6 112 781 0 767 1 0 1 1 0 8 0 amappl5 104 1115 0 1101 1 0 1 1 0 8 0 amappl4 96 6935 0 6894 4 2 2 2 0 8 0 amappl3 88 3147 0 3139 1 0 1 1 0 8 0 amappl2 80 54050 0 53975 3 1 2 3 0 8 0 amappl1 72 167453 0 167016 26 16 10 20 0 8 0 amappl 80 24986 0 24903 2 0 2 2 0 84 0 dma4096 4096 1 0 1 1 1 0 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 17 0 17 1 1 0 1 0 8 0 aobjpl 64 137 0 8 3 0 3 3 0 8 0 uaddrrnd 24 7043 0 6934 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 7043 0 6934 1 0 1 1 0 8 0 vmmpekpl 168 66747 0 66703 3 0 3 3 0 8 0 vmmpepl 168 907242 0 904557 742 575 167 180 0 357 38 vmsppl 368 6949 0 6934 2 0 2 2 0 8 0 pdppl 4096 14093 0 14000 18 6 12 12 0 8 0 pvpl 32 2307374 0 2282319 672 456 216 244 0 265 6 pmappl 232 7042 0 6973 8 3 5 5 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 837 0 171 20 0 20 20 0 8 0