panic: WApoRNoIlN_Gc:ac ShPe_L iNtOeTm _LmOaWgEiRc_EDc hOeNc kS:Y SmCbAuLfpL l 2 c-p7u2 4f2r3e5e8 8l iEsXtI Tm o0d iaf i edStopped at savectx+0xb1: movl $0,%gs:0x530 TID PID UID PRFLAGS PFLAGS CPU COMMAND *399332 61040 0 0x2 0 0 syz-executor.0 167434 1758 0 0x12 0 1 sshd savectx() at savectx+0xb1 end of kernel end trace frame: 0x7f7ffffc6c90, 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 0xfffffd806d6a0400+16 0x0!=0x384b754648993b30 ddb{0}> trace savectx() at savectx+0xb1 end of kernel end trace frame: 0x7f7ffffc6c90, count: -1 ddb{0}> show registers rdi 0 rsi 0 rbp 0xffff800020edc990 rbx 0 rdx 0x8b rcx 0x2 rax 0x39 r8 0xffff800020edc8c0 r9 0xffffffff81379bbf kprintf+0x16f r10 0x1 r11 0xa69f6aee2d402233 r12 0 r13 0 r14 0xffff800020ddcc38 r15 0 rip 0xffffffff823673f1 savectx+0xb1 cs 0x8 rflags 0x46 rsp 0xffff800020edc910 ss 0x10 savectx+0xb1: movl $0,%gs:0x530 ddb{0}> show proc PROC (syz-executor.0) pid=399332 stat=onproc flags process=2 proc=0 pri=16, usrpri=76, nice=20 forw=0xffffffffffffffff, list=0xffff800020ddd868,0xffff800020e37298 process=0xffff800020df0010 user=0xffff800020ed7000, vmspace=0xfffffd807efffa10 estcpu=36, cpticks=3, pctcpu=0.6 user=0, sys=2, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 32994 7440 61040 0 2 0 syz-executor.0 65951 158089 4162 0 2 0 syz-executor.1 65951 330687 4162 0 2 0x4000000 syz-executor.1 4162 78424 48602 0 3 0x82 nanosleep syz-executor.1 56712 489314 0 0 3 0x14200 bored sosplice 35392 464683 0 0 3 0x14280 nfsidl nfsio 58988 229312 0 0 3 0x14280 nfsidl nfsio 34282 440099 0 0 3 0x14280 nfsidl nfsio 40566 219556 0 0 3 0x14280 nfsidl nfsio 42817 502100 0 0 3 0x14280 nfsidl nfsio 7912 234239 0 0 3 0x14280 nfsidl nfsio 8733 301621 0 0 3 0x14280 nfsidl nfsio 49209 228772 0 0 3 0x14280 nfsidl nfsio 94218 158129 0 0 3 0x14280 nfsidl nfsio 26733 183991 0 0 3 0x14280 nfsidl nfsio 98668 214522 0 0 3 0x14280 nfsidl nfsio 9549 42934 0 0 3 0x14280 nfsidl nfsio 4142 185477 0 0 3 0x14280 nfsidl nfsio 2659 262491 0 0 3 0x14280 nfsidl nfsio 11336 440012 0 0 3 0x14280 nfsidl nfsio 29729 393732 0 0 3 0x14280 nfsidl nfsio 67078 330018 0 0 3 0x14280 nfsidl nfsio 90037 420554 0 0 3 0x14280 nfsidl nfsio 3058 485283 0 0 3 0x14280 nfsidl nfsio 74141 432724 0 0 3 0x14280 nfsidl nfsio *61040 399332 48602 0 7 0x2 syz-executor.0 48602 476136 63749 0 3 0x82 thrsleep syz-fuzzer 48602 354823 63749 0 3 0x4000082 nanosleep syz-fuzzer 48602 467425 63749 0 3 0x4000082 thrsleep syz-fuzzer 48602 235056 63749 0 3 0x4000082 thrsleep syz-fuzzer 48602 11056 63749 0 3 0x4000082 thrsleep syz-fuzzer 48602 223369 63749 0 3 0x4000082 nanosleep syz-fuzzer 48602 144527 63749 0 3 0x4000082 thrsleep syz-fuzzer 48602 10150 63749 0 2 0x4000002 syz-fuzzer 63749 472208 1758 0 3 0x10008a pause ksh 1758 167434 76659 0 7 0x12 sshd 6399 280853 1 0 3 0x100083 ttyin getty 76659 246687 1 0 3 0x80 select sshd 75806 92977 16230 74 3 0x100092 bpf pflogd 16230 228857 1 0 3 0x80 netio pflogd 72248 183032 45596 73 3 0x100090 kqread syslogd 45596 38609 1 0 3 0x100082 netio syslogd 88591 24656 1 77 3 0x100090 poll dhclient 53575 234667 1 0 3 0x80 poll dhclient 56059 389838 0 0 3 0x14200 bored smr 92867 100144 0 0 2 0x14200 zerothread 36212 229126 0 0 3 0x14200 aiodoned aiodoned 23650 461782 0 0 3 0x14200 syncer update 93633 64636 0 0 3 0x14200 cleaner cleaner 69923 464465 0 0 3 0x14200 reaper reaper 69801 455892 0 0 3 0x14200 pgdaemon pagedaemon 80910 433012 0 0 3 0x14200 bored crynlk 1250 307845 0 0 3 0x14200 bored crypto 41160 392968 0 0 3 0x40014200 acpi0 acpi0 583 98425 0 0 3 0x40014200 idle1 22703 104282 0 0 3 0x14200 bored softnet 10332 197065 0 0 3 0x14200 bored systqmp 6360 403286 0 0 3 0x14200 bored systq 42003 11273 0 0 3 0x40014200 bored softclock 78867 4558 0 0 3 0x40014200 idle0 1 391292 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 (0xffffffff828eca20) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #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:367 #6 uvm_uarea_alloc+0x51 sys/uvm/uvm_glue.c:274 #7 fork1+0x271 sys/kern/kern_fork.c:365 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #9 Xsyscall+0x128 Process 61040 (syz-executor.0) thread 0xffff800020ddcc38 (399332) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82934728) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #1 syscall+0x400 mi_syscall sys/sys/syscall_mi.h:93 [inline] #1 syscall+0x400 sys/arch/amd64/amd64/trap.c:570 #2 Xsyscall+0x128 exclusive mutex &uvm.fpageqlock r = 0 (0xffffffff828eca20) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #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:367 #6 uvm_uarea_alloc+0x51 sys/uvm/uvm_glue.c:274 #7 fork1+0x271 sys/kern/kern_fork.c:365 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #9 Xsyscall+0x128 Process 1758 (sshd) thread 0xffff800020e4d760 (167434) exclusive rwlock netlock r = 0 (0xffffffff82716f68) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #1 solock+0x5a sys/kern/uipc_socket2.c:282 #2 sosend+0x559 sys/kern/uipc_socket.c:543 #3 dofilewritev+0x1b6 sys/kern/sys_generic.c:365 #4 sys_write+0x83 sys/kern/sys_generic.c:285 #5 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [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 9518 6927K 7379K 78643K 11284 0 pcb 13 8K 8K 78643K 41 0 rtable 110 4K 8K 78643K 288 0 ifaddr 54 12K 13K 78643K 79 0 counters 43 33K 34K 78643K 47 0 ioctlops 0 0K 4K 78643K 1495 0 iov 0 0K 12K 78643K 13 0 mount 1 1K 1K 78643K 1 0 vnodes 1223 77K 77K 78643K 1398 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 4 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 1K 78643K 48 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1824 197K 290K 78643K 13058 0 file desc 6 17K 25K 78643K 211 0 sigio 0 0K 0K 78643K 2 0 proc 60 63K 83K 78643K 481 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 28 0 in_multi 46 2K 3K 78643K 79 0 ether_multi 1 0K 0K 78643K 5 0 mrt 0 0K 0K 78643K 4 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 37 175K 175K 78643K 37 0 exec 0 0K 1K 78643K 226 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 175 75K 75K 78643K 1654 0 UVM aobj 7 2K 2K 78643K 9 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 18 0 NDP 7 0K 0K 78643K 18 0 temp 92 3859K 3923K 78643K 5054 0 kqueue 3 4K 16K 78643K 19 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 8 0 2 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 21 0 19 1 0 1 1 0 8 0 rtentry 112 63 0 19 2 0 2 2 0 8 0 unpcb 120 89 0 79 1 0 1 1 0 8 0 syncache 264 5 0 5 2 1 1 1 0 8 1 tcpcb 544 45 0 41 1 0 1 1 0 8 0 inpcb 296 180 0 173 2 0 2 2 0 8 1 rttmr 72 2 0 2 1 0 1 1 0 8 1 nd6 48 13 0 7 1 0 1 1 0 8 0 pkpcb 40 229 0 229 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 pfrktable 1344 12 0 10 1 0 1 1 0 8 0 pfstitem 24 26 0 1 1 0 1 1 0 8 0 pfstkey 112 26 0 1 1 0 1 1 0 8 0 pfstate 328 26 0 1 3 0 3 3 0 8 0 pfrule 1360 24 0 17 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 245 0 57 13 0 13 13 0 8 1 art_table 32 246 0 57 2 0 2 2 0 8 0 art_node 16 62 0 22 1 0 1 1 0 8 0 sysvmsgpl 40 27 0 15 1 0 1 1 0 8 0 semupl 112 2 0 2 1 0 1 1 0 8 1 semapl 112 36 0 26 1 0 1 1 0 8 0 shmpl 112 6 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1620 0 219 88 0 88 88 0 8 0 ffsino 272 1620 0 219 94 0 94 94 0 8 0 nchpl 144 2052 0 459 60 0 60 60 0 8 0 uvmvnodes 72 1828 0 0 34 0 34 34 0 8 0 vnodes 208 1828 0 0 97 0 97 97 0 8 0 namei 1024 5618 0 5618 1 0 1 1 0 8 1 percpumem 16 34 0 2 1 0 1 1 0 8 0 vcpupl 1984 8 0 0 1 0 1 1 0 8 0 vmpool 560 8 0 0 1 0 1 1 0 8 0 pfiaddrpl 120 5 0 3 1 0 1 1 0 8 0 scxspl 192 6061 0 6061 8 4 4 7 0 8 4 plimitpl 152 25 0 17 1 0 1 1 0 8 0 sigapl 424 444 0 391 6 0 6 6 0 8 0 futexpl 56 2599 0 2599 1 0 1 1 0 8 1 knotepl 112 90 0 70 1 0 1 1 0 8 0 kqueuepl 144 28 0 26 1 0 1 1 0 8 0 pipepl 304 90 0 79 2 0 2 2 0 8 1 fdescpl 496 408 0 391 3 0 3 3 0 8 0 filepl 152 2197 0 2095 5 0 5 5 0 8 1 lockfpl 104 69 0 68 1 0 1 1 0 8 0 lockfspl 48 25 0 24 1 0 1 1 0 8 0 sessionpl 112 19 0 8 1 0 1 1 0 8 0 pgrppl 48 25 0 14 1 0 1 1 0 8 0 ucredpl 96 144 0 135 1 0 1 1 0 8 0 zombiepl 144 391 0 391 1 0 1 1 0 8 1 processpl 992 444 0 391 7 0 7 7 0 8 0 procpl 624 808 0 747 6 0 6 6 0 8 1 sosppl 128 2 0 2 1 0 1 1 0 8 1 sockpl 400 519 0 500 5 1 4 4 0 8 2 mcl64k 65536 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 3 0 0 1 0 1 1 0 8 0 mcl9k 9216 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 3 0 0 1 0 1 1 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 171 0 0 21 0 21 21 0 8 0 mtagpl 96 19 0 0 1 0 1 1 0 8 0 mbufpl 256 189 0 0 12 0 12 12 0 8 0 bufpl 280 3578 0 127 247 0 247 247 0 8 0 anonpl 16 55526 0 39172 74 1 73 73 0 124 0 amapchunkpl 152 2391 0 2101 14 0 14 14 0 158 0 amappl16 192 1512 0 686 42 0 42 42 0 8 0 amappl15 184 89 0 85 1 0 1 1 0 8 0 amappl14 176 83 0 79 1 0 1 1 0 8 0 amappl13 168 35 0 32 1 0 1 1 0 8 0 amappl12 160 25 0 22 1 0 1 1 0 8 0 amappl11 152 139 0 123 1 0 1 1 0 8 0 amappl10 144 40 0 33 1 0 1 1 0 8 0 amappl9 136 364 0 363 1 0 1 1 0 8 0 amappl8 128 385 0 341 2 0 2 2 0 8 0 amappl7 120 148 0 133 1 0 1 1 0 8 0 amappl6 112 30 0 25 1 0 1 1 0 8 0 amappl5 104 225 0 209 1 0 1 1 0 8 0 amappl4 96 581 0 548 1 0 1 1 0 8 0 amappl3 88 207 0 198 1 0 1 1 0 8 0 amappl2 80 2301 0 2229 2 0 2 2 0 8 0 amappl1 72 20194 0 19760 23 13 10 18 0 8 0 amappl 80 1101 0 1015 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 8 0 2 1 0 1 1 0 8 0 uaddrrnd 24 416 0 391 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 416 0 391 1 0 1 1 0 8 0 vmmpekpl 168 7300 0 7256 3 0 3 3 0 8 0 vmmpepl 168 58846 0 56715 134 9 125 125 0 357 31 vmsppl 368 415 0 391 3 0 3 3 0 8 0 pdppl 4096 839 0 790 7 0 7 7 0 8 0 pvpl 32 183850 0 164272 174 0 174 174 0 265 2 pmappl 232 415 0 391 2 0 2 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 262 0 4 8 0 8 8 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace savectx() at savectx+0xb1 end of kernel end trace frame: 0x7f7ffffc6c90, count: -1 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffff800020d70ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:352 x86_ipi_handler() at x86_ipi_handler+0xc6 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 x86_bus_space_io_write_1(3f8,0,64) at x86_bus_space_io_write_1+0x45 sys/arch/amd64/amd64/bus_space.c:759 comcnputc(800,64) at comcnputc+0x131 bus_space_barrier machine/bus.h:481 [inline] comcnputc(800,64) at comcnputc+0x131 sys/dev/ic/com.c:1254 cnputc(64) at cnputc+0x4c sys/dev/cons.c:239 kputchar(64,5,0) at kputchar+0x219 sys/kern/subr_prf.c:354 kprintf() at kprintf+0x15c sys/kern/subr_prf.c:710 panic(ffffffff82407375) at panic+0xfb vprintf sys/kern/subr_prf.c:538 [inline] panic(ffffffff82407375) at panic+0xfb sys/kern/subr_prf.c:208 pool_cache_get(ffffffff828d9e68) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff828d9e68) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff828d9e68,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 tcp_output(ffff800000ad8980) at tcp_output+0x14e6 tcp_usrreq(fffffd806eafac88,9,fffffd807f00e200,0,0,ffff800020e4d760) at tcp_usrreq+0xa55 end trace frame: 0xffff800020e62aa0, count: 0 ddb{1}> trace x86_ipi_db(ffff800020d70ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:352 x86_ipi_handler() at x86_ipi_handler+0xc6 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 x86_bus_space_io_write_1(3f8,0,64) at x86_bus_space_io_write_1+0x45 sys/arch/amd64/amd64/bus_space.c:759 comcnputc(800,64) at comcnputc+0x131 bus_space_barrier machine/bus.h:481 [inline] comcnputc(800,64) at comcnputc+0x131 sys/dev/ic/com.c:1254 cnputc(64) at cnputc+0x4c sys/dev/cons.c:239 kputchar(64,5,0) at kputchar+0x219 sys/kern/subr_prf.c:354 kprintf() at kprintf+0x15c sys/kern/subr_prf.c:710 panic(ffffffff82407375) at panic+0xfb vprintf sys/kern/subr_prf.c:538 [inline] panic(ffffffff82407375) at panic+0xfb sys/kern/subr_prf.c:208 pool_cache_get(ffffffff828d9e68) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff828d9e68) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff828d9e68,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 tcp_output(ffff800000ad8980) at tcp_output+0x14e6 tcp_usrreq(fffffd806eafac88,9,fffffd807f00e200,0,0,ffff800020e4d760) at tcp_usrreq+0xa55 sosend(fffffd806eafac88,0,ffff800020e62b68,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:555 dofilewritev(ffff800020e4d760,4,ffff800020e62b68,0,ffff800020e62c50) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff800020e4d760,ffff800020e62c00,ffff800020e62c50) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020e62cd0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020e62cd0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffbcaf0, count: -19