panic: pr_find_pagehead: mbufpl: page header missing Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *246501 45494 0 0 0x4000000 0 syz-executor.1 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821e3a76) at panic+0x15c sys/kern/subr_prf.c:207 pool_do_put(ffffffff825405f8,fffffd802ccd0000) at pool_do_put+0x36a pool_put(ffffffff825405f8,fffffd802ccd0000) at pool_put+0x4b sys/kern/subr_pool.c:802 m_free(fffffd802ccd0000) at m_free+0x119 sys/kern/uipc_mbuf.c:459 ml_purge(ffff800017b6a008) at ml_purge+0x50 m_freem sys/kern/uipc_mbuf.c:538 [inline] ml_purge(ffff800017b6a008) at ml_purge+0x50 sys/kern/uipc_mbuf.c:1628 ifq_purge(ffff8000009e6a78) at ifq_purge+0x97 sys/net/ifq.c:423 if_down(ffff8000009e6800) at if_down+0x9c if_linkstate sys/net/if.c:1677 [inline] if_down(ffff8000009e6800) at if_down+0x9c sys/net/if.c:1628 if_setrdomain(ffff8000009e6800,6) at if_setrdomain+0x17c sys/net/if.c:1880 ifioctl(fffffd80363b4d88,8020699f,ffff800017b6a1d0,ffff800014930290) at ifioctl+0x169d sys/net/if.c:2148 sys_ioctl(ffff800014930290,ffff800017b6a2e8,ffff800017b6a330) at sys_ioctl+0x5b9 syscall(ffff800017b6a3b0) at syscall+0x507 sys/arch/amd64/amd64/trap.c:555 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xe4312953010, 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 pr_find_pagehead: mbufpl: page header missing ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821e3a76) at panic+0x15c sys/kern/subr_prf.c:207 pool_do_put(ffffffff825405f8,fffffd802ccd0000) at pool_do_put+0x36a pool_put(ffffffff825405f8,fffffd802ccd0000) at pool_put+0x4b sys/kern/subr_pool.c:802 m_free(fffffd802ccd0000) at m_free+0x119 sys/kern/uipc_mbuf.c:459 ml_purge(ffff800017b6a008) at ml_purge+0x50 m_freem sys/kern/uipc_mbuf.c:538 [inline] ml_purge(ffff800017b6a008) at ml_purge+0x50 sys/kern/uipc_mbuf.c:1628 ifq_purge(ffff8000009e6a78) at ifq_purge+0x97 sys/net/ifq.c:423 if_down(ffff8000009e6800) at if_down+0x9c if_linkstate sys/net/if.c:1677 [inline] if_down(ffff8000009e6800) at if_down+0x9c sys/net/if.c:1628 if_setrdomain(ffff8000009e6800,6) at if_setrdomain+0x17c sys/net/if.c:1880 ifioctl(fffffd80363b4d88,8020699f,ffff800017b6a1d0,ffff800014930290) at ifioctl+0x169d sys/net/if.c:2148 sys_ioctl(ffff800014930290,ffff800017b6a2e8,ffff800017b6a330) at sys_ioctl+0x5b9 syscall(ffff800017b6a3b0) at syscall+0x507 sys/arch/amd64/amd64/trap.c:555 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xe4312953010, count: -13 ddb> show registers rdi 0xffffffff816a1567 db_enter+0x17 rsi 0x28b8 __ALIGN_SIZE+0x18b8 rbp 0xffff800017b69db0 rbx 0xffff800017b69e60 rdx 0x28b9 __ALIGN_SIZE+0x18b9 rcx 0xffff800016b65000 rax 0xffff800016b65000 r8 0xffff800017b69d70 r9 0x1 r10 0xffff8000009e8340 r11 0x3655adfdae864c8d r12 0x3000000008 r13 0xffff800017b69dc0 r14 0x100 r15 0x1 rip 0xffffffff816a1568 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800017b69da0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (syz-executor.1) pid=246501 stat=onproc flags process=0 proc=4000000 pri=67, usrpri=67, nice=20 forw=0xffffffffffffffff, list=0xffff8000149313d8,0xffffffff82579858 process=0xffff8000ffff6a48 user=0xffff800017b65000, vmspace=0xfffffd803f012550 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 45494 71179 32291 0 2 0 syz-executor.1 *45494 246501 32291 0 7 0x4000000 syz-executor.1 68392 379591 0 0 3 0x14200 bored sosplice 16048 64083 2747 0 3 0x2 biowait syz-executor.0 32291 41201 2747 0 3 0x82 nanosleep syz-executor.1 2747 507393 76415 0 3 0x82 thrsleep syz-fuzzer 2747 342559 76415 0 3 0x4000082 nanosleep syz-fuzzer 2747 2921 76415 0 3 0x4000082 thrsleep syz-fuzzer 2747 293519 76415 0 3 0x4000082 thrsleep syz-fuzzer 2747 243452 76415 0 3 0x4000082 thrsleep syz-fuzzer 2747 188097 76415 0 3 0x4000082 kqread syz-fuzzer 2747 270720 76415 0 3 0x4000082 thrsleep syz-fuzzer 76415 441727 37614 0 3 0x10008a pause ksh 37614 242701 26203 0 3 0x92 select sshd 31053 178461 1 0 3 0x100083 ttyin getty 26203 218713 1 0 3 0x80 select sshd 59466 24288 10967 73 3 0x100090 kqread syslogd 10967 155241 1 0 3 0x100082 netio syslogd 46205 90503 1 77 2 0x100090 dhclient 24853 396974 1 0 3 0x80 poll dhclient 28970 403580 0 0 2 0x14200 zerothread 90326 400005 0 0 3 0x14200 aiodoned aiodoned 52684 62205 0 0 3 0x14200 syncer update 31131 168652 0 0 3 0x14200 cleaner cleaner 9635 97912 0 0 3 0x14200 reaper reaper 34545 226529 0 0 3 0x14200 pgdaemon pagedaemon 97066 492435 0 0 3 0x14200 bored crynlk 30098 436047 0 0 3 0x14200 bored crypto 9600 235502 0 0 3 0x40014200 acpi0 acpi0 53043 253911 0 0 3 0x14200 bored softnet 42223 28481 0 0 3 0x14200 bored systqmp 92877 34835 0 0 3 0x14200 bored systq 19915 243919 0 0 3 0x40014200 bored softclock 84710 231480 0 0 3 0x40014200 idle0 5935 147026 0 0 3 0x14200 bored smr 1 281412 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 9506 6721K 6780K 78643K 10849 0 pcb 13 8K 8K 78643K 41 0 rtable 111 4K 4K 78643K 245 0 ifaddr 60 12K 13K 78643K 91 0 counters 19 16K 16K 78643K 19 0 ioctlops 0 0K 2K 78643K 28 0 iov 0 0K 16K 78643K 24 0 mount 1 1K 1K 78643K 1 0 vnodes 1218 77K 77K 78643K 1307 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 1K 78643K 2 0 VM map 2 0K 0K 78643K 2 0 sem 12 0K 0K 78643K 71 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1794 195K 288K 78643K 12646 0 file desc 5 13K 25K 78643K 141 0 sigio 0 0K 0K 78643K 8 0 proc 48 38K 63K 78643K 359 0 subproc 32 2K 2K 78643K 34 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 9 0 in_multi 47 2K 3K 78643K 52 0 ether_multi 1 0K 0K 78643K 4 0 mrt 0 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 42 185K 185K 78643K 42 0 exec 0 0K 1K 78643K 189 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 109 38K 38K 78643K 1188 0 UVM aobj 10 2K 2K 78643K 10 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 24 0 NDP 9 0K 0K 78643K 17 0 temp 117 3025K 3089K 78643K 6011 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 arp 64 6 0 0 1 0 1 1 0 8 0 rtpcb 80 25 0 23 1 0 1 1 0 8 0 rtentry 112 45 0 1 2 0 2 2 0 8 0 unpcb 120 99 0 91 1 0 1 1 0 8 0 syncache 264 6 0 6 2 1 1 1 0 8 1 tcpqe 32 110 0 110 1 1 0 1 0 8 0 tcpcb 544 73 0 69 2 1 1 2 0 8 0 inpcb 280 190 0 182 2 1 1 2 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 4 0 4 1 0 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 212 0 0 14 0 14 14 0 8 0 art_table 32 213 0 0 2 0 2 2 0 8 0 art_node 16 44 0 4 1 0 1 1 0 8 0 sysvmsgpl 40 32 0 32 1 0 1 1 0 8 1 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 69 0 59 1 0 1 1 0 8 0 shmpl 112 8 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1598 0 196 46 0 46 46 0 8 0 ffsino 240 1598 0 196 83 0 83 83 0 8 0 nchpl 144 2033 0 419 60 0 60 60 0 8 0 uvmvnodes 72 1704 0 0 31 0 31 31 0 8 0 vnodes 208 1704 0 0 90 0 90 90 0 8 0 namei 1024 5157 0 5157 1 0 1 1 0 8 1 vcpupl 1984 1 0 0 1 0 1 1 0 8 0 vmpool 528 1 0 0 1 0 1 1 0 8 0 scxspl 192 5368 0 5367 8 3 5 7 0 8 4 plimitpl 152 20 0 13 1 0 1 1 0 8 0 sigapl 432 312 0 299 2 0 2 2 0 8 0 futexpl 56 3535 0 3535 1 0 1 1 0 8 1 knotepl 112 69 0 50 1 0 1 1 0 8 0 kqueuepl 104 31 0 29 1 0 1 1 0 8 0 pipepl 128 206 0 187 1 0 1 1 0 8 0 fdescpl 424 313 0 299 2 0 2 2 0 8 0 filepl 120 2040 0 1944 4 0 4 4 0 8 1 lockfpl 104 39 0 38 1 0 1 1 0 8 0 lockfspl 48 16 0 15 1 0 1 1 0 8 0 sessionpl 112 17 0 7 1 0 1 1 0 8 0 pgrppl 48 21 0 11 1 0 1 1 0 8 0 ucredpl 96 141 0 134 1 0 1 1 0 8 0 zombiepl 144 299 0 299 1 0 1 1 0 8 1 processpl 872 328 0 299 4 0 4 4 0 8 0 procpl 632 492 0 456 4 0 4 4 0 8 0 sosppl 128 3 0 3 1 0 1 1 0 8 1 sockpl 384 314 0 296 4 0 4 4 0 8 2 mcl64k 65536 7 0 7 1 0 1 1 0 8 1 mcl16k 16384 2 0 2 1 0 1 1 0 8 1 mcl12k 12288 2 0 2 1 0 1 1 0 8 1 mcl9k 9216 2 0 2 1 0 1 1 0 8 1 mcl8k 8192 4 0 4 1 0 1 1 0 8 1 mcl4k 4096 23 0 23 2 1 1 1 0 8 1 mcl2k 2048 65819 0 65774 15 7 8 13 0 8 1 mtagpl 80 6 0 4 2 1 1 1 0 8 0 mbufpl 256 105198 0 105108 13 3 10 10 0 8 1 bufpl 280 6331 0 1504 345 0 345 345 0 8 0 anonpl 16 48487 0 29186 82 1 81 81 0 62 3 amapchunkpl 152 1393 0 1244 8 1 7 8 0 158 0 amappl16 192 1657 0 558 58 0 58 58 0 8 3 amappl15 184 163 0 156 1 0 1 1 0 8 0 amappl14 176 25 0 23 1 0 1 1 0 8 0 amappl13 168 54 0 51 1 0 1 1 0 8 0 amappl12 160 5 0 3 1 0 1 1 0 8 0 amappl11 152 48 0 36 1 0 1 1 0 8 0 amappl10 144 10 0 9 1 0 1 1 0 8 0 amappl9 136 567 0 563 1 0 1 1 0 8 0 amappl8 128 109 0 90 1 0 1 1 0 8 0 amappl7 120 90 0 79 1 0 1 1 0 8 0 amappl6 112 57 0 51 1 0 1 1 0 8 0 amappl5 104 138 0 128 1 0 1 1 0 8 0 amappl4 96 578 0 547 1 0 1 1 0 8 0 amappl3 88 121 0 111 1 0 1 1 0 8 0 amappl2 80 1727 0 1655 3 1 2 3 0 8 0 amappl1 72 15256 0 14829 26 16 10 20 0 8 0 amappl 80 716 0 672 2 0 2 2 0 84 1 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 18 0 17 1 0 1 1 0 8 0 aobjpl 64 9 0 0 1 0 1 1 0 8 0 uaddrrnd 24 314 0 299 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 314 0 299 1 0 1 1 0 8 0 vmmpekpl 168 6090 0 6066 2 0 2 2 0 8 0 vmmpepl 168 45659 0 43462 138 12 126 130 0 357 29 vmsppl 272 313 0 299 2 0 2 2 0 8 1 pdppl 4096 634 0 599 6 1 5 6 0 8 0 pvpl 32 153062 0 130781 191 1 190 190 0 265 9 pmappl 200 313 0 299 1 0 1 1 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 147 0 15 4 0 4 4 0 8 0