panic: WpARooNIlN_Gca: cShPeL_i NtOeTm _LmOaWEgRicE_D cOhNe ckS:YS CmAbLuLf pl2 c78pu7 0f00re9e3 0l EiXsItT mo0d iaf i eStopped at savectx+0xb1: movl $0,%gs:0x530 TID PID UID PRFLAGS PFLAGS CPU COMMAND *490521 74274 0 0x2 0 0 syz-executor.0 110703 84400 0 0x12 0 1 sshd savectx() at savectx+0xb1 end of kernel end trace frame: 0x7f7ffffe1c80, count: 14 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 pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806d70c400+16 0x0!=0x43b464085cf7a605 ddb{0}> trace savectx() at savectx+0xb1 end of kernel end trace frame: 0x7f7ffffe1c80, count: -1 ddb{0}> show registers rdi 0 rsi 0 rbp 0xffff800020b65360 rbx 0 rdx 0xffff800020a8b6e0 rcx 0 rax 0x39 r8 0xffffffff8104a77f kprintf+0x16f r9 0x1 r10 0x25 r11 0xb48bcbb65af697f8 r12 0 r13 0 r14 0xffff800020a8b6e0 r15 0 rip 0xffffffff8171d3f1 savectx+0xb1 cs 0x8 rflags 0x46 rsp 0xffff800020b652e0 ss 0x10 savectx+0xb1: movl $0,%gs:0x530 ddb{0}> show proc PROC (syz-executor.0) pid=490521 stat=onproc flags process=2 proc=0 pri=73, usrpri=73, nice=20 forw=0xffffffffffffffff, list=0xffff800020a8b458,0xffff800020a8b1e0 process=0xffff800020a78750 user=0xffff800020b60000, vmspace=0xfffffd807f007730 estcpu=36, cpticks=1, pctcpu=0.18 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 98785 91387 74274 0 2 0 syz-executor.0 4041 458270 0 0 3 0x14200 bored sosplice 82475 43567 63088 0 3 0x2 biowait syz-executor.1 *74274 490521 63088 0 7 0x2 syz-executor.0 63088 358794 42873 0 3 0x82 thrsleep syz-fuzzer 63088 352640 42873 0 3 0x4000082 nanosleep syz-fuzzer 63088 512076 42873 0 3 0x4000082 thrsleep syz-fuzzer 63088 385504 42873 0 3 0x4000082 thrsleep syz-fuzzer 63088 464282 42873 0 3 0x4000082 kqread syz-fuzzer 63088 488099 42873 0 3 0x4000082 thrsleep syz-fuzzer 63088 475237 42873 0 3 0x4000082 thrsleep syz-fuzzer 63088 122157 42873 0 3 0x4000082 nanosleep syz-fuzzer 63088 456264 42873 0 3 0x4000082 thrsleep syz-fuzzer 63088 44407 42873 0 3 0x4000082 thrsleep syz-fuzzer 42873 97286 84400 0 3 0x10008a pause ksh 84400 110703 26975 0 7 0x12 sshd 13008 432882 1 0 3 0x100083 ttyin getty 26975 337748 1 0 3 0x80 select sshd 74443 429808 29055 74 3 0x100092 bpf pflogd 29055 391785 1 0 3 0x80 netio pflogd 94574 194867 32774 73 3 0x100090 kqread syslogd 32774 466933 1 0 3 0x100082 netio syslogd 85815 78517 1 77 3 0x100090 poll dhclient 81906 337007 1 0 3 0x80 poll dhclient 48713 453899 0 0 3 0x14200 pgzero zerothread 44708 385815 0 0 3 0x14200 aiodoned aiodoned 46362 80795 0 0 3 0x14200 syncer update 97981 403520 0 0 3 0x14200 cleaner cleaner 77401 521488 0 0 3 0x14200 reaper reaper 64047 60751 0 0 3 0x14200 pgdaemon pagedaemon 609 173018 0 0 3 0x14200 bored crynlk 61138 378596 0 0 3 0x14200 bored crypto 27106 249284 0 0 3 0x40014200 acpi0 acpi0 79823 451024 0 0 3 0x40014200 idle1 14154 292749 0 0 3 0x14200 bored softnet 4422 348933 0 0 3 0x14200 bored systqmp 46694 180213 0 0 3 0x14200 bored systq 49700 31087 0 0 3 0x40014200 bored softclock 8259 85543 0 0 3 0x40014200 idle0 75427 134752 0 0 3 0x14200 bored smr 1 462593 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks CPU 0: exclusive mutex &uvm.fpageqlock r = 0 (0xffffffff82691258) #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 uvm_pmr_getpages+0x34e sys/uvm/uvm_pmemrange.c:822 #4 uvm_pglistalloc+0x362 sys/uvm/uvm_page.c:790 #5 uvm_km_kmemalloc_pla+0x238 sys/uvm/uvm_km.c:368 #6 uvm_uarea_alloc+0x51 sys/uvm/uvm_glue.c:274 #7 fork1+0x295 sys/kern/kern_fork.c:366 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #9 Xsyscall+0x128 Process 82475 (syz-executor.1) thread 0xffff800020a8b1d0 (43567) exclusive rrwlock inode r = 0 (0xfffffd806e2466f8) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:453 #3 VOP_LOCK+0xf0 sys/kern/vfs_vops.c:615 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:571 #5 vget+0x1c3 sys/kern/vfs_subr.c:672 #6 ufs_ihashget+0x141 sys/ufs/ufs/ufs_ihash.c:119 #7 ffs_vget+0x74 sys/ufs/ffs/ffs_vfsops.c:1323 #8 ufs_lookup+0x14b4 sys/ufs/ufs/ufs_lookup.c:487 #9 VOP_LOOKUP+0x5b sys/kern/vfs_vops.c:91 #10 vfs_lookup+0x7a6 sys/kern/vfs_lookup.c:568 #11 namei+0x63c sys/kern/vfs_lookup.c:249 #12 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1776 #13 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #13 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806e246c48) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:453 #3 VOP_LOCK+0xf0 sys/kern/vfs_vops.c:615 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:571 #5 vget+0x1c3 sys/kern/vfs_subr.c:672 #6 cache_lookup+0x2bb sys/kern/vfs_cache.c:224 #7 ufs_lookup+0x1bc sys/ufs/ufs/ufs_lookup.c:162 #8 VOP_LOOKUP+0x5b sys/kern/vfs_vops.c:91 #9 vfs_lookup+0x7a6 sys/kern/vfs_lookup.c:568 #10 namei+0x63c sys/kern/vfs_lookup.c:249 #11 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1776 #12 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #12 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #13 Xsyscall+0x128 Process 74274 (syz-executor.0) thread 0xffff800020a8b6e0 (490521) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8263eb08) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 syscall+0x400 mi_syscall sys/sys/syscall_mi.h:83 [inline] #1 syscall+0x400 sys/arch/amd64/amd64/trap.c:555 #2 Xsyscall+0x128 exclusive mutex &uvm.fpageqlock r = 0 (0xffffffff82691258) #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 uvm_pmr_getpages+0x34e sys/uvm/uvm_pmemrange.c:822 #4 uvm_pglistalloc+0x362 sys/uvm/uvm_page.c:790 #5 uvm_km_kmemalloc_pla+0x238 sys/uvm/uvm_km.c:368 #6 uvm_uarea_alloc+0x51 sys/uvm/uvm_glue.c:274 #7 fork1+0x295 sys/kern/kern_fork.c:366 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #9 Xsyscall+0x128 Process 84400 (sshd) thread 0xffff800020ac1be8 (110703) exclusive rwlock netlock r = 0 (0xffffffff824bff78) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 solock+0x5a sys/kern/uipc_socket2.c:282 #2 sosend+0x51b sys/kern/uipc_socket.c:512 #3 dofilewritev+0x1b7 sys/kern/sys_generic.c:364 #4 sys_write+0x83 sys/kern/sys_generic.c:284 #5 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #5 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #6 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9529 6608K 6856K 78643K 10881 0 pcb 13 8K 8K 78643K 51 0 rtable 108 4K 4K 78643K 237 0 ifaddr 69 13K 13K 78643K 86 0 counters 39 33K 33K 78643K 39 0 ioctlops 0 0K 4K 78643K 1473 0 iov 0 0K 24K 78643K 21 0 mount 1 1K 1K 78643K 1 0 vnodes 1221 77K 77K 78643K 1309 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 7 0 VM map 4 2K 2K 78643K 4 0 sem 12 0K 1K 78643K 63 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 5 13K 25K 78643K 135 0 sigio 0 0K 0K 78643K 12 0 proc 60 63K 95K 78643K 443 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 15 0 in_multi 47 2K 2K 78643K 63 0 ether_multi 1 0K 0K 78643K 7 0 mrt 0 0K 0K 78643K 2 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 54 238K 238K 78643K 54 0 exec 0 0K 1K 78643K 220 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 40K 78643K 1397 0 UVM aobj 17 2K 2K 78643K 17 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 11 0K 0K 78643K 17 0 temp 117 3579K 3644K 78643K 4381 0 kqueue 0 0K 0K 78643K 1 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> 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 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 96 25 0 23 1 0 1 1 0 8 0 rtentry 112 45 0 1 2 0 2 2 0 8 0 unpcb 120 184 0 174 1 0 1 1 0 8 0 syncache 280 4 0 4 1 1 0 1 0 8 0 tcpqe 32 228 0 228 1 1 0 1 0 8 0 tcpcb 640 82 0 78 1 0 1 1 0 8 0 inpcb 280 327 0 320 2 0 2 2 0 8 1 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 1 0 1 1 0 1 1 0 8 1 pffrag 232 3 0 3 1 0 1 1 0 482 1 pffrnode 88 3 0 3 1 0 1 1 0 8 1 pffrent 40 135 0 135 1 0 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 24 0 0 1 0 1 1 0 8 0 pfstkey 112 24 0 0 1 0 1 1 0 8 0 pfstate 328 24 0 0 2 0 2 2 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 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 27 0 21 1 0 1 1 0 8 0 semupl 112 4 0 4 1 0 1 1 0 8 1 semapl 112 61 0 51 1 0 1 1 0 8 0 shmpl 112 15 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1591 0 184 46 0 46 46 0 8 0 ffsino 272 1591 0 184 94 0 94 94 0 8 0 nchpl 144 1981 0 362 61 0 61 61 0 8 0 uvmvnodes 72 1697 0 0 31 0 31 31 0 8 0 vnodes 208 1697 0 0 90 0 90 90 0 8 0 namei 1024 5394 0 5394 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 2 0 0 1 0 1 1 0 8 0 vmpool 552 2 0 0 1 0 1 1 0 8 0 scsiplug 64 1 0 1 1 0 1 1 0 8 1 scxspl 208 5687 0 5686 8 1 7 7 0 8 6 plimitpl 152 23 0 15 1 0 1 1 0 8 0 sigapl 432 333 0 318 3 1 2 3 0 8 0 futexpl 56 3077 0 3077 1 0 1 1 0 8 1 knotepl 112 64 0 45 1 0 1 1 0 8 0 kqueuepl 104 34 0 32 1 0 1 1 0 8 0 pipepl 160 280 0 261 2 0 2 2 0 8 1 fdescpl 488 334 0 318 3 0 3 3 0 8 0 filepl 152 2352 0 2251 6 0 6 6 0 8 2 lockfpl 104 50 0 49 1 0 1 1 0 8 0 lockfspl 48 20 0 19 1 0 1 1 0 8 0 sessionpl 128 18 0 7 1 0 1 1 0 8 0 pgrppl 48 20 0 9 1 0 1 1 0 8 0 ucredpl 96 159 0 150 1 0 1 1 0 8 0 zombiepl 144 318 0 318 1 0 1 1 0 8 1 processpl 928 350 0 318 5 0 5 5 0 8 0 procpl 648 631 0 590 5 0 5 5 0 8 1 sosppl 144 35 0 35 1 0 1 1 0 8 1 sockpl 384 540 0 521 5 0 5 5 0 8 3 mcl64k 65536 8 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 5 0 0 1 0 1 1 0 8 0 mcl2k 2048 147 0 0 18 0 18 18 0 8 0 mtagpl 80 11 0 0 1 0 1 1 0 8 0 mbufpl 256 241 0 0 15 0 15 15 0 8 0 bufpl 280 6582 0 1314 377 0 377 377 0 8 0 anonpl 16 51792 0 32092 87 1 86 86 0 124 6 amapchunkpl 152 1945 0 1790 14 0 14 14 0 158 5 amappl16 192 1717 0 640 56 0 56 56 0 8 2 amappl14 176 50 0 43 1 0 1 1 0 8 0 amappl12 160 59 0 53 2 1 1 1 0 8 0 amappl11 152 106 0 90 1 0 1 1 0 8 0 amappl10 144 16 0 10 1 0 1 1 0 8 0 amappl9 136 600 0 597 1 0 1 1 0 8 0 amappl8 128 166 0 140 2 0 2 2 0 8 0 amappl7 120 37 0 34 1 0 1 1 0 8 0 amappl6 112 108 0 98 1 0 1 1 0 8 0 amappl5 104 186 0 170 1 0 1 1 0 8 0 amappl4 96 530 0 502 1 0 1 1 0 8 0 amappl3 88 162 0 156 1 0 1 1 0 8 0 amappl2 80 1733 0 1670 3 1 2 3 0 8 0 amappl1 72 17314 0 16887 26 16 10 20 0 8 0 amappl 80 886 0 840 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 18 0 17 1 0 1 1 0 8 0 aobjpl 64 16 0 0 1 0 1 1 0 8 0 uaddrrnd 24 336 0 318 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 336 0 318 1 0 1 1 0 8 0 vmmpekpl 168 6967 0 6931 2 0 2 2 0 8 0 vmmpepl 168 48337 0 46141 141 10 131 135 0 357 32 vmsppl 368 333 0 318 2 0 2 2 0 8 0 pdppl 4096 679 0 638 6 0 6 6 0 8 0 pvpl 32 166754 0 143934 202 0 202 202 0 265 15 pmappl 232 335 0 318 2 0 2 2 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 162 0 3 5 0 5 5 0 8 0