login: panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd8078163200+16 0x0!=0xfe39af3701c6720a Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *421448 26355 0 0x12 0 0 sshd 302299 96358 0 0x14000 0x200 1 reaper db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8240acfd) at panic+0x164 sys/kern/subr_prf.c:218 pool_cache_get(ffffffff828ce6d0) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff828ce6d0) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff828ce6d0,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd806db71c00,580,580,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd806db71c00,580,580,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 tcp_output(ffff800000adb030) at tcp_output+0x15ba sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd806eafbc88,9,fffffd806db71c00,0,0,ffff8000fffff8c0) at tcp_usrreq+0xa55 sosend(fffffd806eafbc88,0,ffff800020e24438,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:555 dofilewritev(ffff8000fffff8c0,4,ffff800020e24438,0,ffff800020e24520) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff8000fffff8c0,ffff800020e244d0,ffff800020e24520) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020e245a0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020e245a0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd11d0, count: 3 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 0xfffffd8078163200+16 0x0!=0xfe39af3701c6720a ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8240acfd) at panic+0x164 sys/kern/subr_prf.c:218 pool_cache_get(ffffffff828ce6d0) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff828ce6d0) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff828ce6d0,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd806db71c00,580,580,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd806db71c00,580,580,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 tcp_output(ffff800000adb030) at tcp_output+0x15ba sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd806eafbc88,9,fffffd806db71c00,0,0,ffff8000fffff8c0) at tcp_usrreq+0xa55 sosend(fffffd806eafbc88,0,ffff800020e24438,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:555 dofilewritev(ffff8000fffff8c0,4,ffff800020e24438,0,ffff800020e24520) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff8000fffff8c0,ffff800020e244d0,ffff800020e24520) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020e245a0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020e245a0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd11d0, count: -12 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800020e23dd0 rbx 0xffff800020e23e80 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffff800020e23d90 r9 0xffffffff814bc41f kprintf+0x16f r10 0x1 r11 0x7ef3e45a6cbc3eb8 r12 0x3000000008 r13 0xffff800020e23de0 r14 0x100 r15 0x1 rip 0xffffffff81c991c8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020e23dc0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (sshd) pid=421448 stat=onproc flags process=12 proc=0 pri=24, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffffe500,0xffff8000ffffe298 process=0xffff8000ffffc3f0 user=0xffff800020e1f000, vmspace=0xfffffd806e91aa18 estcpu=1, cpticks=2, pctcpu=0.5 user=0, sys=2, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 55145 198943 59245 0 2 0x482 syz-executor.1 85916 341685 59245 0 2 0x2 syz-executor.0 59245 199770 55388 0 3 0x82 thrsleep syz-fuzzer 59245 187440 55388 0 3 0x4000082 nanosleep syz-fuzzer 59245 395008 55388 0 3 0x4000082 thrsleep syz-fuzzer 59245 26455 55388 0 2 0x4000002 syz-fuzzer 59245 293038 55388 0 3 0x4000082 thrsleep syz-fuzzer 59245 417078 55388 0 3 0x4000082 thrsleep syz-fuzzer 59245 329802 55388 0 3 0x4000082 thrsleep syz-fuzzer 59245 488306 55388 0 3 0x4000082 kqread syz-fuzzer 55388 152703 26355 0 3 0x10008a pause ksh *26355 421448 67059 0 7 0x12 sshd 61077 172319 1 0 3 0x100083 ttyin getty 67059 153369 1 0 3 0x80 select sshd 20221 142833 31026 74 3 0x100092 bpf pflogd 31026 142590 1 0 3 0x80 netio pflogd 88146 141034 78318 73 3 0x100090 kqread syslogd 78318 37230 1 0 3 0x100082 netio syslogd 83612 83902 1 77 3 0x100090 poll dhclient 94559 360853 1 0 3 0x80 poll dhclient 68885 401902 0 0 3 0x14200 bored smr 12767 403433 0 0 2 0x14200 zerothread 63990 213548 0 0 3 0x14200 aiodoned aiodoned 2327 261064 0 0 3 0x14200 syncer update 66292 231773 0 0 3 0x14200 cleaner cleaner 96358 302299 0 0 7 0x14200 reaper 17109 345082 0 0 3 0x14200 pgdaemon pagedaemon 17018 483075 0 0 3 0x14200 bored crynlk 14050 467226 0 0 3 0x14200 bored crypto 46841 416317 0 0 3 0x40014200 acpi0 acpi0 75421 494928 0 0 3 0x40014200 idle1 49487 491379 0 0 2 0x14200 softnet 14842 324924 0 0 3 0x14200 bored systqmp 69261 29959 0 0 3 0x14200 bored systq 62722 428841 0 0 3 0x40014200 bored softclock 76798 103889 0 0 3 0x40014200 idle0 1 512663 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks CPU 1: