panic:W ARpNooIlNG_:c aSchPeL_i NtOemT_ mLOagWEiRc_EDc heONck S: YSCmAbLufLp l2 -cp1u 5f7r3e3e84 5li9s0 tE mXoITdi f0i ea d : Stopped at savectx+0xb1: movl $0,%gs:0x530 TID PID UID PRFLAGS PFLAGS CPU COMMAND *498732 93764 0 0x2 0 0 syz-executor.0 119508 4840 0 0x12 0 1 sshd savectx() at savectx+0xb1 end of kernel end trace frame: 0x7f7ffffee290, 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 0xfffffd8062d4c700+16 0x0!=0x901259ca266d3bfe ddb{0}> trace savectx() at savectx+0xb1 end of kernel end trace frame: 0x7f7ffffee290, count: -1 ddb{0}> show registers rdi 0 rsi 0 rbp 0xffff800021bc1a10 rbx 0 rdx 0xffff800020ac8780 rcx 0 rax 0x3b r8 0xffffffff816b7fbf kprintf+0x16f r9 0x1 r10 0x25 r11 0xab4b97ed7376b3a2 r12 0 r13 0 r14 0xffff800020ac8780 r15 0 rip 0xffffffff819f03f1 savectx+0xb1 cs 0x8 rflags 0x46 rsp 0xffff800021bc1990 ss 0x10 savectx+0xb1: movl $0,%gs:0x530 ddb{0}> show proc PROC (syz-executor.0) pid=498732 stat=onproc flags process=2 proc=0 pri=78, usrpri=78, nice=20 forw=0xffffffffffffffff, list=0xffff800020ac9650,0xffff800020ac8a08 process=0xffff800020af4000 user=0xffff800021bbc000, vmspace=0xfffffd807f000b80 estcpu=28, cpticks=1, pctcpu=0.9 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 78013 58007 93764 0 2 0 syz-executor.0 *93764 498732 71685 0 7 0x2 syz-executor.0 48842 75633 0 0 3 0x14200 bored sosplice 99901 392723 71685 0 3 0x2 biowait syz-executor.1 71685 381281 92223 0 2 0x2 syz-fuzzer 71685 350086 92223 0 3 0x4000082 nanosleep syz-fuzzer 71685 138712 92223 0 3 0x4000082 nanosleep syz-fuzzer 71685 387292 92223 0 3 0x4000082 thrsleep syz-fuzzer 71685 324624 92223 0 3 0x4000082 thrsleep syz-fuzzer 71685 326038 92223 0 3 0x4000082 thrsleep syz-fuzzer 71685 403529 92223 0 3 0x4000082 thrsleep syz-fuzzer 71685 163443 92223 0 3 0x4000082 thrsleep syz-fuzzer 71685 435176 92223 0 3 0x4000082 thrsleep syz-fuzzer 71685 212799 92223 0 3 0x4000082 thrsleep syz-fuzzer 92223 382472 4840 0 3 0x10008a pause ksh 4840 119508 19201 0 7 0x12 sshd 66208 429893 1 0 3 0x100083 ttyin getty 19201 119176 1 0 3 0x80 select sshd 34021 236147 8623 74 3 0x100092 bpf pflogd 8623 518199 1 0 3 0x80 netio pflogd 6329 3801 84119 73 3 0x100090 kqread syslogd 84119 150059 1 0 3 0x100082 netio syslogd 18814 228474 0 0 3 0x14200 pgzero zerothread 46264 74051 0 0 3 0x14200 aiodoned aiodoned 87045 136013 0 0 3 0x14200 syncer update 94322 297482 0 0 3 0x14200 cleaner cleaner 50616 393128 0 0 3 0x14200 reaper reaper 56208 136776 0 0 3 0x14200 pgdaemon pagedaemon 26871 169921 0 0 3 0x14200 bored crynlk 90966 139339 0 0 3 0x14200 bored crypto 65542 389620 0 0 3 0x40014200 acpi0 acpi0 34515 120686 0 0 3 0x40014200 idle1 26439 41892 0 0 3 0x14200 bored softnet 44076 171908 0 0 3 0x14200 bored systqmp 84765 366182 0 0 3 0x14200 bored systq 5159 44906 0 0 3 0x40014200 bored softclock 60763 517590 0 0 3 0x40014200 idle0 58260 26301 0 0 3 0x14200 bored smr 1 34627 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 (0xffffffff82645368) #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:941 #4 uvm_pglistalloc+0x362 sys/uvm/uvm_page.c:790 #5 uvm_km_kmemalloc_pla+0x238 sys/uvm/uvm_km.c:366 #6 uvm_uarea_alloc+0x51 sys/uvm/uvm_glue.c:274 #7 fork1+0x295 sys/kern/kern_fork.c:365 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #9 Xsyscall+0x128 Process 93764 (syz-executor.0) thread 0xffff800020ac8780 (498732) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82663c50) #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:570 #2 Xsyscall+0x128 exclusive mutex &uvm.fpageqlock r = 0 (0xffffffff82645368) #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:941 #4 uvm_pglistalloc+0x362 sys/uvm/uvm_page.c:790 #5 uvm_km_kmemalloc_pla+0x238 sys/uvm/uvm_km.c:366 #6 uvm_uarea_alloc+0x51 sys/uvm/uvm_glue.c:274 #7 fork1+0x295 sys/kern/kern_fork.c:365 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #9 Xsyscall+0x128 Process 99901 (syz-executor.1) thread 0xffff800020ac8290 (392723) exclusive rrwlock inode r = 0 (0xfffffd80664e42c0) #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+0xf9 sys/kern/vfs_vops.c:615 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:571 #5 vget+0x1c8 sys/kern/vfs_subr.c:671 #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+0x14b7 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:570 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806acab4d8) #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+0xf9 sys/kern/vfs_vops.c:615 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:571 #5 vfs_lookup+0xe6 sys/kern/vfs_lookup.c:419 #6 namei+0x63c sys/kern/vfs_lookup.c:249 #7 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1776 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #9 Xsyscall+0x128 Process 4840 (sshd) thread 0xffff800020ad9b38 (119508) exclusive rwlock netlock r = 0 (0xffffffff824f5708) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 solock+0x5a sys/kern/uipc_socket2.c:282 #2 sosend+0x559 sys/kern/uipc_socket.c:537 #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:570 #6 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9504 6344K 7249K 78643K 11304 0 pcb 13 8K 8K 78643K 63 0 rtable 104 3K 4K 78643K 362 0 ifaddr 69 14K 14K 78643K 160 0 counters 39 33K 33K 78643K 39 0 ioctlops 0 0K 4K 78643K 1491 0 iov 0 0K 16K 78643K 45 0 mount 1 1K 1K 78643K 1 0 vnodes 1224 77K 77K 78643K 1436 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 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 45 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 5 13K 25K 78643K 280 0 sigio 0 0K 0K 78643K 13 0 proc 56 51K 95K 78643K 523 0 subproc 32 2K 2K 78643K 51 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 20 0 in_multi 57 3K 3K 78643K 118 0 ether_multi 1 0K 0K 78643K 5 0 mrt 1 0K 0K 78643K 3 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 55 254K 254K 78643K 55 0 exec 0 0K 1K 78643K 252 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 117 87K 87K 78643K 1940 0 UVM aobj 16 5K 5K 78643K 18 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 36 0 NDP 11 0K 0K 78643K 38 0 temp 111 3014K 3079K 78643K 18335 0 kqueue 3 4K 26K 78643K 32 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 9 0 3 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 43 0 43 1 0 1 1 0 8 1 rtentry 112 77 0 35 2 0 2 2 0 8 0 unpcb 120 244 0 235 1 0 1 1 0 8 0 syncache 264 6 0 6 2 2 0 1 0 8 0 tcpqe 32 36 0 36 1 1 0 1 0 8 0 tcpcb 544 65 0 61 1 0 1 1 0 8 0 inpcb 280 657 0 653 3 0 3 3 0 8 2 rttmr 72 1 0 1 1 1 0 1 0 8 0 nd6 48 11 0 8 1 0 1 1 0 8 0 pkpcb 40 4 0 4 1 0 1 1 0 8 1 ppxss 1128 10 0 10 1 0 1 1 0 8 1 pffrag 232 4 0 4 1 0 1 1 0 482 1 pffrnode 88 4 0 4 1 0 1 1 0 8 1 pffrent 40 180 0 180 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 32 0 5 1 0 1 1 0 8 0 pfstkey 112 32 0 5 1 0 1 1 0 8 0 pfstate 328 32 0 5 3 0 3 3 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 256 379 0 179 15 1 14 15 0 8 1 art_table 32 380 0 179 2 0 2 2 0 8 0 art_node 16 76 0 37 1 0 1 1 0 8 0 sysvmsgpl 40 37 0 21 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 43 0 33 1 0 1 1 0 8 0 shmpl 112 16 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1804 0 399 46 0 46 46 0 8 0 ffsino 272 1804 0 399 95 0 95 95 0 8 0 nchpl 144 2412 0 810 61 0 61 61 0 8 0 uvmvnodes 72 2010 0 0 37 0 37 37 0 8 0 vnodes 208 2010 0 0 106 0 106 106 0 8 0 namei 1024 6892 0 6892 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 7 0 0 1 0 1 1 0 8 0 vmpool 560 7 0 0 1 0 1 1 0 8 0 scxspl 192 7317 0 7316 8 6 2 7 0 8 1 plimitpl 152 34 0 27 1 0 1 1 0 8 0 sigapl 432 476 0 463 3 1 2 3 0 8 0 futexpl 56 5103 0 5103 1 0 1 1 0 8 1 knotepl 112 155 0 136 3 2 1 3 0 8 0 kqueuepl 104 70 0 68 1 0 1 1 0 8 0 pipelkpl 48 142 0 132 1 0 1 1 0 8 0 pipepl 120 284 0 265 2 1 1 2 0 8 0 fdescpl 496 477 0 463 3 0 3 3 0 8 0 filepl 152 3448 0 3359 6 1 5 6 0 8 1 lockfpl 104 85 0 85 1 0 1 1 0 8 1 lockfspl 48 34 0 34 1 0 1 1 0 8 1 sessionpl 112 19 0 10 1 0 1 1 0 8 0 pgrppl 48 29 0 20 1 0 1 1 0 8 0 ucredpl 96 416 0 408 1 0 1 1 0 8 0 zombiepl 144 463 0 463 1 0 1 1 0 8 1 processpl 896 493 0 463 4 0 4 4 0 8 0 procpl 632 1095 0 1056 6 1 5 5 0 8 1 srpgc 64 2 0 2 1 1 0 1 0 8 0 sosppl 128 8 0 8 2 1 1 1 0 8 1 sockpl 400 948 0 935 5 0 5 5 0 8 2 mcl64k 65536 5 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 3 0 0 1 0 1 1 0 8 0 mcl8k 8192 5 0 0 1 0 1 1 0 8 0 mcl4k 4096 6 0 0 1 0 1 1 0 8 0 mcl2k 2048 171 0 0 21 0 21 21 0 8 0 mtagpl 80 15 0 0 1 0 1 1 0 8 0 mbufpl 256 263 0 0 16 0 16 16 0 8 0 bufpl 280 7257 0 1344 423 0 423 423 0 8 0 anonpl 16 65046 0 49713 66 1 65 65 0 125 1 amapchunkpl 152 2616 0 2493 8 1 7 8 0 158 1 amappl16 192 2329 0 1492 55 8 47 54 0 8 4 amappl15 184 61 0 58 1 0 1 1 0 8 0 amappl14 176 35 0 32 1 0 1 1 0 8 0 amappl12 160 60 0 59 2 1 1 1 0 8 0 amappl11 152 183 0 173 1 0 1 1 0 8 0 amappl10 144 22 0 16 1 0 1 1 0 8 0 amappl9 136 617 0 613 1 0 1 1 0 8 0 amappl8 128 129 0 106 1 0 1 1 0 8 0 amappl7 120 110 0 98 1 0 1 1 0 8 0 amappl6 112 184 0 175 1 0 1 1 0 8 0 amappl5 104 193 0 181 1 0 1 1 0 8 0 amappl4 96 733 0 705 1 0 1 1 0 8 0 amappl3 88 142 0 135 1 0 1 1 0 8 0 amappl2 80 2829 0 2768 3 1 2 3 0 8 0 amappl1 72 20795 0 20392 26 16 10 21 0 8 0 amappl 80 1374 0 1333 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 17 0 2 1 0 1 1 0 8 0 uaddrrnd 24 484 0 463 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 484 0 463 1 0 1 1 0 8 0 vmmpekpl 168 7781 0 7741 2 0 2 2 0 8 0 vmmpepl 168 66539 0 64629 124 10 114 120 0 357 23 vmsppl 368 483 0 463 2 0 2 2 0 8 0 pdppl 4096 975 0 933 6 0 6 6 0 8 0 pvpl 32 205701 0 187304 161 3 158 161 0 265 4 pmappl 232 483 0 463 3 1 2 2 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 173 0 4 5 0 5 5 0 8 0