panic: chgproccnt: procs < 0 Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *197734 58346 0 0x10 0x4000000 0 syz-executor 207154 28426 0 0x2 0 1K syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff835447fd) at panic+0x1e5 sys/kern/subr_prf.c:198 chgproccnt(ee00,ffffffff) at chgproccnt+0xcc sys_setresuid(ffff8000fffe9248,ffff80002a281ff0,ffff80002a281f40) at sys_setresuid+0x577 sys/kern/kern_prot.c:421 syscall(ffff80002a281ff0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a281ff0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xe4d58359bb0, count: 9 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 *cpu0: chgproccnt: procs < 0 ddb{0}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff835447fd) at panic+0x1e5 sys/kern/subr_prf.c:198 chgproccnt(ee00,ffffffff) at chgproccnt+0xcc sys_setresuid(ffff8000fffe9248,ffff80002a281ff0,ffff80002a281f40) at sys_setresuid+0x577 sys/kern/kern_prot.c:421 syscall(ffff80002a281ff0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a281ff0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xe4d58359bb0, count: -6 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff80002a281db0 rbx 0xffffffff83992e07 cpu_info_full_primary+0x2e07 rdx 0xffff80000002a740 rcx 0xffff8000fffe9248 rax 0xffffffff83991ff0 cpu_info_full_primary+0x1ff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0x7fa40d3c9d999e20 r11 0x8f7bb2da6d3d39e4 r12 0xffffffff83992c08 cpu_info_full_primary+0x2c08 r13 0 r14 0 r15 0x1 rip 0xffffffff82e5bf15 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a281da0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor) tid=197734 pid=58346 tcnt=3 stat=onproc flags process=10 proc=4000000 runpri=50, usrpri=50, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff8000fffe8020,0xffff8000fffe8fc0 process=0xffff80003bbaeb70 user=0xffff80002a27d000, vmspace=0xfffffd806f33d990 estcpu=36, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 40969 275765 38921 0 2 0x102004 sh 2203 33453 38375 0 2 0 syz-executor 2203 213938 38375 0 3 0x4000080 fsleep syz-executor 2203 94826 38375 0 3 0x4000080 fsleep syz-executor 79410 298561 57529 0 2 0 syz-executor 36725 94064 2889 0 2 0 syz-executor 36725 93423 2889 0 3 0x4000080 fsleep syz-executor 38921 403002 71796 0 3 0x10008a sigsusp sh 58346 417432 8611 0 2 0x10 syz-executor *58346 197734 8611 0 7 0x4000010 syz-executor 58346 388672 8611 0 2 0x4000010 syz-executor 71796 189478 55289 0 3 0x82 wait syz-executor 6084 509604 1 0 3 0x82 nanoslp getty 24248 104616 55289 0 3 0x82 wait syz-executor 38375 308027 55289 0 3 0x82 nanoslp syz-executor 57529 97112 55289 0 3 0x82 nanoslp syz-executor 2889 367635 55289 0 3 0x82 nanoslp syz-executor 28426 207154 55289 0 7 0x2 syz-executor 8611 288770 55289 0 3 0x82 nanoslp syz-executor 55289 518538 1 0 3 0x82 wait syz-executor 94023 197037 1 74 3 0x1100092 bpf pflogd 24599 255622 1 73 3 0x1100090 kqread syslogd 47855 318560 0 0 3 0x14200 bored smr 39143 374933 0 0 2 0x14200 zerothread 81795 133079 0 0 3 0x14200 aiodoned aiodoned 19130 350365 0 0 3 0x14200 syncer update 36552 74525 0 0 3 0x14200 cleaner cleaner 46206 454014 0 0 3 0x14200 reaper reaper 3888 312860 0 0 3 0x14200 pgdaemon pagedaemon 18831 423820 0 0 3 0x14200 bored viomb 585 277251 0 0 3 0x40014200 acpi0 acpi0 44101 470492 0 0 3 0x40014200 idle1 50727 444290 0 0 3 0x14200 bored softnet1 60301 127618 0 0 3 0x14200 bored softnet0 95816 273558 0 0 3 0x14200 bored systqmp 76239 353150 0 0 3 0x14200 bored systq 70674 32234 0 0 3 0x14200 tmoslp softclockmp 56644 119724 0 0 3 0x40014200 tmoslp softclock 8357 30321 0 0 3 0x40014200 idle0 1 463595 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks CPU 1: exclusive mutex &uvm.fpageqlock r = 0 (0xffffffff83a9e7c0) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 mtx_enter+0x4b4 sys/kern/kern_lock.c:487 #2 uvm_pmr_getpages+0x461 sys/uvm/uvm_pmemrange.c:-1 #3 uvm_pmr_cache_alloc+0xd0 sys/uvm/uvm_pmemrange.c:2249 #4 uvm_pmr_cache_get+0x1af sys/uvm/uvm_pmemrange.c:2283 #5 uvm_pagealloc+0x230 sys/uvm/uvm_page.c:909 #6 uvmfault_promote+0x135 sys/uvm/uvm_fault.c:-1 #7 uvm_fault_upper+0x6aa sys/uvm/uvm_fault.c:1081 #8 uvm_fault+0x198 sys/uvm/uvm_fault.c:635 #9 upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192 #10 usertrap+0x430 sys/arch/amd64/amd64/trap.c:640 #11 recall_trap+0x8 Process 40969 (sh) thread 0xffff8000ffffca68 (275765) exclusive rwlock amaplk r = 0 (0xfffffd806f308448) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320 #2 uvm_fault_check+0x8a9 sys/uvm/uvm_fault.c:834 #3 uvm_fault+0x106 sys/uvm/uvm_fault.c:627 #4 upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192 #5 usertrap+0x430 sys/arch/amd64/amd64/trap.c:640 #6 recall_trap+0x8 shared rwlock vmmaplk r = 0 (0xfffffd806e859110) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 rw_do_enter_read+0x3e8 sys/kern/kern_rwlock.c:413 #2 uvmfault_lookup+0x122 sys/uvm/uvm_fault.c:1880 #3 uvm_fault_check+0x4f sys/uvm/uvm_fault.c:693 #4 uvm_fault+0x106 sys/uvm/uvm_fault.c:627 #5 upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192 #6 usertrap+0x430 sys/arch/amd64/amd64/trap.c:640 #7 recall_trap+0x8 Process 58346 (syz-executor) thread 0xffff8000fffe9248 (197734) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff83aaab00) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 __mp_acquire_count+0x58 sys/kern/kern_lock.c:-1 #2 malloc+0xe3 sys/kern/kern_malloc.c:175 #3 uid_find+0xab sys/kern/kern_proc.c:136 #4 chgproccnt+0x39 sys/kern/kern_proc.c:-1 #5 sys_setresuid+0x577 sys/kern/kern_prot.c:421 #6 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #6 syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 #7 Xsyscall+0x128 Process 28426 (syz-executor) thread 0xffff80002a2222a8 (207154) exclusive rrwlock inode r = 0 (0xfffffd806c8617b0) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320 #2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:576 #5 vget+0x2a2 sys/kern/vfs_subr.c:686 #6 ufs_ihashget+0x185 sys/ufs/ufs/ufs_ihash.c:98 #7 ffs_vget+0x8c sys/ufs/ffs/ffs_vfsops.c:1203 #8 ufs_lookup+0x1a36 sys/ufs/ufs/ufs_lookup.c:478 #9 VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85 #10 vfs_lookup+0x963 sys/kern/vfs_lookup.c:580 #11 namei+0x7c5 sys/kern/vfs_lookup.c:250 #12 dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1893 #13 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #13 syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806d1c49f8) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320 #2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:576 #5 vfs_lookup+0x12b sys/kern/vfs_lookup.c:431 #6 namei+0x7c5 sys/kern/vfs_lookup.c:250 #7 dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1893 #8 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #8 syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 #9 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11089 12082K 12284K 166960K 12334 0 pcb 17 12K 12K 166960K 39 0 rtable 205 7K 8K 166960K 530 0 pf 35 17K 18K 166960K 75 0 ifaddr 37 6K 7K 166960K 76 0 ifgroup 55 2K 2K 166960K 100 0 sysctl 1 1K 9K 166960K 6 0 counters 70 37K 37K 166960K 102 0 ioctlops 0 0K 4K 166960K 1508 0 iov 0 0K 12K 166960K 5 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1324 83K 84K 166960K 1578 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 3 0 VM map 2 1K 1K 166960K 2 0 sem 10 0K 0K 166960K 16 0 dirhash 12 2K 2K 166960K 21 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 17 61K 93K 166960K 329 0 sigio 0 0K 0K 166960K 4 0 proc 21 33K 180K 166960K 720 0 subproc 72 4K 4K 166960K 126 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 148 0 in_multi 77 5K 7K 166960K 158 0 ether_multi 1 0K 0K 166960K 3 0 mrt 1 0K 0K 166960K 9 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 241 1076K 1076K 166960K 241 0 exec 1 0K 1K 166960K 477 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 149 92K 185K 166960K 4528 0 UVM aobj 5 2K 2K 166960K 5 0 pinsyscall 23 46K 106K 166960K 1661 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 1K 166960K 40 0 NDP 14 0K 2K 166960K 52 0 temp 39 9113K 9238K 166960K 11471 0 kqueue 3 4K 26K 166960K 46 0 SYN cache 2 16K 16K 166960K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 26 0 0 1 0 1 1 0 8 0 rtpcb 120 51 0 51 1 1 0 1 0 8 0 rtentry 176 167 0 78 6 1 5 6 0 8 0 unpcb 144 99 0 94 2 1 1 2 0 8 0 syncache 336 4 0 4 1 1 0 1 0 8 0 tcpcb 736 35 0 34 1 0 1 1 0 8 0 arp 136 28 0 14 1 0 1 1 0 8 0 inpcb 328 239 0 237 6 5 1 6 0 8 0 nd6 152 40 0 21 1 0 1 1 0 8 0 pkpcb 40 3 0 3 1 1 0 1 0 8 0 kcovpl 48 14 0 6 1 0 1 1 0 8 0 ppxss 1192 8 0 8 1 1 0 1 0 8 0 pfosfp 40 1428 0 1005 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 30 0 0 1 0 1 1 0 8 0 pfstkey 128 31 0 1 1 0 1 1 0 8 0 pfstate 448 31 0 1 4 0 4 4 0 8 0 pfrule 1360 22 0 17 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 703 0 320 30 1 29 30 0 8 0 art_table 40 704 0 320 5 0 5 5 0 8 0 art_node 32 167 0 86 1 0 1 1 0 8 0 sysvmsgpl 40 1 0 1 1 1 0 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 72 12 0 4 1 0 1 1 0 8 0 shmpl 112 2 0 0 1 0 1 1 0 8 0 dirhash 1024 23 0 6 3 0 3 3 0 8 0 dino2pl 256 1845 0 371 93 0 93 93 0 8 0 ffsino 296 1845 0 371 114 0 114 114 0 8 0 nchpl 144 2218 0 497 64 0 64 64 0 8 0 rtmask 32 2 0 2 1 1 0 1 0 8 0 vnodes 216 2067 0 0 115 0 115 115 0 8 0 namei 1024 7759 0 7757 2 1 1 1 0 8 0 percpumem 16 66 0 16 1 0 1 1 0 8 0 kstatmem 264 57 0 28 3 1 2 3 0 8 0 scsiplug 72 1 0 1 1 0 1 1 0 8 1 scxspl 216 7468 0 7467 4 3 1 3 1 8 0 plimitpl 152 115 0 103 1 0 1 1 0 8 0 sigapl 424 647 0 610 7 1 6 7 0 8 0 knotepl 120 68 0 0 3 0 3 3 0 8 0 kqueuepl 224 53 0 51 1 0 1 1 0 8 0 pipepl 344 156 0 129 3 0 3 3 0 8 0 fdescpl 528 631 0 610 3 0 3 3 0 8 0 filepl 160 2892 0 2720 12 2 10 12 0 8 0 lockfpl 104 116 0 116 1 1 0 1 0 8 0 lockfspl 48 25 0 25 1 1 0 1 0 8 0 sessionpl 144 37 0 32 1 0 1 1 0 8 0 pgrppl 48 52 0 39 1 0 1 1 0 8 0 ucredpl 104 389 0 380 1 0 1 1 0 8 0 zombiepl 144 614 0 612 1 0 1 1 0 8 0 processpl 1232 647 0 610 5 0 5 5 0 8 0 procpl 664 839 0 797 6 1 5 6 0 8 0 sockpl 752 397 0 390 8 6 2 8 0 8 0 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 133 0 0 17 0 17 17 0 8 0 mcl2k 2048 18 0 0 3 0 3 3 0 8 0 mtagpl 96 2 0 0 1 0 1 1 0 8 0 mbufpl 256 136 0 0 9 0 9 9 0 8 0 bufpl 280 3738 0 106 260 0 260 260 0 8 0 anonpl 32 7497 0 0 61 0 61 61 0 246 0 amapchunkpl 152 12940 0 12576 25 5 20 25 0 158 0 amappl16 200 2168 0 2150 14 11 3 14 0 8 0 amappl15 192 4 0 4 1 1 0 1 0 8 0 amappl14 184 501 0 499 1 0 1 1 0 8 0 amappl13 176 138 0 135 1 0 1 1 0 8 0 amappl12 168 932 0 912 2 0 2 2 0 8 0 amappl11 160 18 0 18 1 1 0 1 0 8 0 amappl10 152 77 0 73 1 0 1 1 0 8 0 amappl9 144 270 0 270 1 1 0 1 0 8 0 amappl8 136 232 0 231 1 0 1 1 0 8 0 amappl7 128 166 0 161 1 0 1 1 0 8 0 amappl6 120 208 0 207 1 0 1 1 0 8 0 amappl5 112 102 0 100 1 0 1 1 0 8 0 amappl4 104 416 0 409 1 0 1 1 0 8 0 amappl3 96 2448 0 2368 4 1 3 4 0 8 0 amappl2 88 614 0 596 2 0 2 2 0 8 0 amappl1 80 11784 0 11601 15 4 11 15 0 8 0 amappl 88 3656 0 3534 5 1 4 5 0 92 0 uvmvnodes 80 104 0 0 3 0 3 3 0 8 0 dma8192 8192 1 0 1 1 1 0 1 0 8 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 7 0 7 2 2 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 4 0 0 1 0 1 1 0 8 0 uaddrrnd 24 631 0 610 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 631 0 610 1 0 1 1 0 8 0 vmmpekpl 168 7106 0 7064 3 0 3 3 0 8 0 vmmpepl 168 49838 0 48886 96 43 53 96 0 357 0 vmsppl 488 630 0 610 5 1 4 5 0 8 0 rwobjpl 80 17443 0 16923 27 4 23 27 0 8 0 pdppl 4096 1269 0 1220 105 54 51 85 0 8 2 pvpl 32 14615 0 0 118 0 118 118 0 265 0 pmappl 256 630 0 610 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 281 0 62 8 0 8 8 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff835447fd) at panic+0x1e5 sys/kern/subr_prf.c:198 chgproccnt(ee00,ffffffff) at chgproccnt+0xcc sys_setresuid(ffff8000fffe9248,ffff80002a281ff0,ffff80002a281f40) at sys_setresuid+0x577 sys/kern/kern_prot.c:421 syscall(ffff80002a281ff0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a281ff0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xe4d58359bb0, count: -6 ddb{0}> machine ddbcpu 1