panic(ffffffff821f1840) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff826874f8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff826874f8) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff826874f8,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd8063e12100,0,3b9aca00,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd8063e12100,0,3b9aca00,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 ether_resolve(ffff80000017b2a8,fffffd8063e12100,fffffd806f6f35f8,fffffd806f52f1c0,ffff800022d90ef8) at ether_resolve+0x49f sys/net/if_ethersubr.c:227 ether_output(ffff80000017b2a8,fffffd8063e12100,fffffd806f6f35f8,fffffd806f52f1c0) at ether_output+0x47 ether_encap sys/net/if_ethersubr.c:310 [inline] ether_output(ffff80000017b2a8,fffffd8063e12100,fffffd806f6f35f8,fffffd806f52f1c0) at ether_output+0x47 sys/net/if_ethersubr.c:339 ip_output(fffffd8063e16500,0,fffffd806f6f35e8,0,0,fffffd806f6f3578) at ip_output+0x12a2 sys/netinet/ip_output.c:509 udp_output(fffffd806f6f3578,fffffd8063e16500,0,0) at udp_output+0x5af sys/netinet/udp_usrreq.c:1008 sosend(fffffd806483a340,0,ffff800022d91220,0,0,0) at sosend+0x671 sys/kern/uipc_socket.c:549 sendit(ffff800020ac6eb8,f,ffff800022d91300,0,ffff800022d913e0) at sendit+0x52b sys/kern/uipc_syscalls.c:657 sys_sendto(ffff800020ac6eb8,ffff800022d91398,ffff800022d913e0) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:522 syscall(ffff800022d91460) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800022d91460) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x20c11006100, count: 1 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{1}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd8063e10900+16 0x0!=0x3d291c4e135f5ba3 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821f1840) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff826874f8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff826874f8) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff826874f8,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd8063e12100,0,3b9aca00,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd8063e12100,0,3b9aca00,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 ether_resolve(ffff80000017b2a8,fffffd8063e12100,fffffd806f6f35f8,fffffd806f52f1c0,ffff800022d90ef8) at ether_resolve+0x49f sys/net/if_ethersubr.c:227 ether_output(ffff80000017b2a8,fffffd8063e12100,fffffd806f6f35f8,fffffd806f52f1c0) at ether_output+0x47 ether_encap sys/net/if_ethersubr.c:310 [inline] ether_output(ffff80000017b2a8,fffffd8063e12100,fffffd806f6f35f8,fffffd806f52f1c0) at ether_output+0x47 sys/net/if_ethersubr.c:339 ip_output(fffffd8063e16500,0,fffffd806f6f35e8,0,0,fffffd806f6f3578) at ip_output+0x12a2 sys/netinet/ip_output.c:509 udp_output(fffffd806f6f3578,fffffd8063e16500,0,0) at udp_output+0x5af sys/netinet/udp_usrreq.c:1008 sosend(fffffd806483a340,0,ffff800022d91220,0,0,0) at sosend+0x671 sys/kern/uipc_socket.c:549 sendit(ffff800020ac6eb8,f,ffff800022d91300,0,ffff800022d913e0) at sendit+0x52b sys/kern/uipc_syscalls.c:657 sys_sendto(ffff800020ac6eb8,ffff800022d91398,ffff800022d913e0) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:522 syscall(ffff800022d91460) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800022d91460) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x20c11006100, count: -14 ddb{1}> show registers rdi 0xffffffff819b5d77 db_enter+0x17 rsi 0xc66b __ALIGN_SIZE+0xb66b rbp 0xffff800022d90bd0 rbx 0xffff800022d90c80 rdx 0xc66c __ALIGN_SIZE+0xb66c rcx 0xffff800021b6e000 rax 0xffff800021b6e000 r8 0xffffffff8188868f kprintf+0x16f r9 0x1 r10 0x25 r11 0x74f5524b381fa8f7 r12 0x3000000008 r13 0xffff800022d90be0 r14 0x100 r15 0x1 rip 0xffffffff819b5d78 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800022d90bc0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=441722 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020ac6c48,0xffff800020ac6028 process=0xffff800020a92ba8 user=0xffff800022d8c000, vmspace=0xfffffd807efff8a0 estcpu=36, cpticks=3, pctcpu=0.0 user=0, sys=3, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 17875 69367 36083 0 2 0 syz-executor.0 17875 322929 36083 0 2 0x4000000 syz-executor.0 42628 268448 87421 0 7 0 syz-executor.1 *42628 441722 87421 0 7 0x4000000 syz-executor.1 42628 503289 87421 0 3 0x4000080 fsleep syz-executor.1 10900 63766 0 0 3 0x14200 bored sosplice 87421 38762 55934 0 2 0x482 syz-executor.1 36083 233205 55934 0 2 0x482 syz-executor.0 55934 68368 98401 0 3 0x82 kqread syz-fuzzer 55934 350565 98401 0 3 0x4000082 thrsleep syz-fuzzer 55934 198698 98401 0 3 0x4000082 thrsleep syz-fuzzer 55934 513416 98401 0 3 0x4000082 thrsleep syz-fuzzer 55934 80367 98401 0 3 0x4000082 thrsleep syz-fuzzer 55934 306889 98401 0 3 0x4000082 thrsleep syz-fuzzer 55934 160259 98401 0 3 0x4000082 thrsleep syz-fuzzer 55934 263278 98401 0 3 0x4000082 thrsleep syz-fuzzer 55934 362568 98401 0 3 0x4000082 thrsleep syz-fuzzer 55934 411220 98401 0 3 0x4000082 thrsleep syz-fuzzer 98401 303129 96064 0 3 0x10008a pause ksh 96064 21999 20442 0 3 0x92 select sshd 36570 225472 1 0 3 0x100083 ttyin getty 20442 498669 1 0 3 0x80 select sshd 17669 469708 66547 74 2 0x100492 pflogd 66547 380886 1 0 3 0x80 netio pflogd 50526 196018 29967 73 3 0x100090 kqread syslogd 29967 10508 1 0 3 0x100082 netio syslogd 75544 422564 1 77 3 0x100090 poll dhclient 62080 123110 1 0 3 0x80 poll dhclient 98957 403425 0 0 3 0x14200 bored smr 14745 444320 0 0 2 0x14200 zerothread 26192 246712 0 0 3 0x14200 aiodoned aiodoned 94060 44857 0 0 3 0x14200 syncer update 18870 2377 0 0 3 0x14200 cleaner cleaner 87428 68597 0 0 3 0x14200 reaper reaper 66250 484297 0 0 3 0x14200 pgdaemon pagedaemon 99026 375319 0 0 3 0x14200 bored crynlk 90895 256671 0 0 3 0x14200 bored crypto 10437 372465 0 0 3 0x40014200 acpi0 acpi0 59585 185877 0 0 3 0x40014200 idle1 62536 373479 0 0 2 0x14200 softnet 40826 8152 0 0 3 0x14200 bored systqmp 62423 88681 0 0 3 0x14200 bored systq 60360 37517 0 0 2 0x40014200 softclock 37964 171491 0 0 3 0x40014200 idle0 1 67310 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks CPU 0: exclusive mutex /syzkaller/managers/multicore/kernel/sys/kern/uipc_mbuf.c:132 r = 0 (0xffffffff82513500) #0 witness_lock+0x4c5 sys/kern/subr_witness.c:1164 #1 mtx_enter_try+0x102 #2 mtx_enter+0x4b sys/kern/kern_lock.c:266 #3 m_extfree+0x36 m_extunref sys/kern/uipc_mbuf.c:489 [inline] #3 m_extfree+0x36 sys/kern/uipc_mbuf.c:517 #4 m_free+0x135 sys/kern/uipc_mbuf.c:456 #5 m_freem+0x40 sys/kern/uipc_mbuf.c:538 #6 vio_txeof+0x139 sys/dev/pv/if_vio.c:1137 #7 vio_tx_intr+0x38 sys/dev/pv/if_vio.c:1113 #8 intr_handler+0x8f sys/arch/amd64/amd64/intr.c:529 #9 Xintr_ioapic_edge20_untramp+0x19f #10 __sanitizer_cov_trace_const_cmp4+0xb sys/dev/kcov.c:197 #11 userret+0x360 sys/kern/kern_sig.c:1893 #12 syscall+0x55f mi_syscall_return sys/sys/syscall_mi.h:129 [inline] #12 syscall+0x55f sys/arch/amd64/amd64/trap.c:592 #13 Xsyscall+0x128 Process 17875 (syz-executor.0) thread 0xffff800020ac6018 (322929) exclusive rrwlock inode r = 0 (0xfffffd80641bbf80) #0 witness_lock+0x4c5 sys/kern/subr_witness.c:1164 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:311 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:462 #3 VOP_LOCK+0x4b sys/kern/vfs_vops.c:602 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:575 #5 sys_ftruncate+0x13d sys/kern/vfs_syscalls.c:2844 #6 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #6 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #7 Xsyscall+0x128 Process 42628 (syz-executor.1) thread 0xffff800020ac69d8 (268448) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82689ce8) #0 witness_lock+0x4c5 sys/kern/subr_witness.c:1164 #1 intr_handler+0x5e sys/arch/amd64/amd64/intr.c:525 #2 Xintr_ioapic_edge20_untramp+0x19f #3 __sanitizer_cov_trace_const_cmp4+0xb sys/dev/kcov.c:197 #4 userret+0x360 sys/kern/kern_sig.c:1893 #5 syscall+0x55f mi_syscall_return sys/sys/syscall_mi.h:129 [inline] #5 syscall+0x55f sys/arch/amd64/amd64/trap.c:592 #6 Xsyscall+0x128 Process 42628 (syz-executor.1) thread 0xffff800020ac6eb8 (441722) exclusive rwlock netlock r = 0 (0xffffffff824a7948) #0 witness_lock+0x4c5 sys/kern/subr_witness.c:1164 #1 solock+0x5a sys/kern/uipc_socket2.c:282 #2 sosend+0x559 sys/kern/uipc_socket.c:537 #3 sendit+0x52b sys/kern/uipc_syscalls.c:657 #4 sys_sendto+0x80 sys/kern/uipc_syscalls.c:522 #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{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9519 6416K 7124K 78643K 11685 0 pcb 13 8K 8K 78643K 95 0 rtable 105 4K 4K 78643K 264 0 ifaddr 74 14K 15K 78643K 101 0 counters 43 33K 34K 78643K 51 0 ioctlops 0 0K 4K 78643K 1477 0 iov 0 0K 16K 78643K 47 0 mount 1 1K 1K 78643K 1 0 vnodes 1221 77K 77K 78643K 1519 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 5 0 VM map 2 1K 1K 78643K 2 0 sem 11 0K 0K 78643K 12 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 6 17K 25K 78643K 246 0 sigio 0 0K 0K 78643K 5 0 proc 62 63K 95K 78643K 455 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 11 0 in_multi 49 2K 2K 78643K 79 0 ether_multi 1 0K 0K 78643K 10 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 49 228K 228K 78643K 49 0 exec 0 0K 1K 78643K 232 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 106 21K 37K 78643K 1739 0 UVM aobj 8 2K 3K 78643K 10 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 50 0 NDP 12 0K 0K 78643K 21 0 temp 103 3043K 3111K 78643K 10640 0 kqueue 3 4K 12K 78643K 21 0 SYN cache 2 16K 16K 78643K 2 0 ddb{1}> 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 80 25 0 23 1 0 1 1 0 8 0 rtentry 112 51 0 10 2 0 2 2 0 8 0 unpcb 120 180 0 164 1 0 1 1 0 8 0 syncache 264 12 0 12 2 1 1 1 0 8 1 tcpqe 32 19 0 19 2 2 0 1 0 8 0 tcpcb 544 187 0 181 2 0 2 2 0 8 1 inpcb 280 543 0 530 2 0 2 2 0 8 1 rttmr 72 2 0 2 1 0 1 1 0 8 1 nd6 48 7 0 3 1 0 1 1 0 8 0 pkpcb 40 125 0 125 1 0 1 1 0 8 1 swfcl 56 2 0 0 1 0 1 1 0 8 0 ppxss 1128 1 0 1 1 0 1 1 0 8 1 pffrag 232 5 0 4 1 0 1 1 0 482 0 pffrnode 88 5 0 4 1 0 1 1 0 8 0 pffrent 40 108 0 94 1 0 1 1 0 8 0 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 35 0 2 1 0 1 1 0 8 0 pfstkey 112 35 0 2 1 0 1 1 0 8 0 pfstate 328 35 0 2 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 256 211 0 40 13 0 13 13 0 8 0 art_table 32 212 0 40 2 0 2 2 0 8 0 art_node 16 50 0 12 1 0 1 1 0 8 0 sysvmsgpl 40 10 0 7 1 0 1 1 0 8 0 semapl 112 9 0 0 1 0 1 1 0 8 0 shmpl 112 8 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1754 0 348 46 0 46 46 0 8 0 ffsino 272 1754 0 348 95 0 95 95 0 8 0 nchpl 144 2280 0 673 61 0 61 61 0 8 0 uvmvnodes 72 2049 0 0 38 0 38 38 0 8 0 vnodes 208 2049 0 0 108 0 108 108 0 8 0 namei 1024 6227 0 6227 1 0 1 1 0 8 1 percpumem 16 36 0 4 1 0 1 1 0 8 0 vmpool 560 2 0 2 1 0 1 1 0 8 1 scxspl 192 7245 0 7245 6 4 2 5 0 8 2 plimitpl 152 35 0 27 1 0 1 1 0 8 0 sigapl 424 462 0 429 4 0 4 4 0 8 0 futexpl 56 4122 0 4121 1 0 1 1 0 8 0 knotepl 112 76 0 57 1 0 1 1 0 8 0 kqueuepl 144 41 0 39 1 0 1 1 0 8 0 pipelkpl 48 115 0 105 1 0 1 1 0 8 0 pipepl 120 230 0 211 1 0 1 1 0 8 0 fdescpl 496 446 0 429 3 0 3 3 0 8 0 filepl 152 2936 0 2823 5 0 5 5 0 8 0 lockfpl 104 62 0 61 1 0 1 1 0 8 0 lockfspl 48 25 0 24 1 0 1 1 0 8 0 sessionpl 112 18 0 7 1 0 1 1 0 8 0 pgrppl 48 21 0 10 1 0 1 1 0 8 0 ucredpl 96 177 0 168 1 0 1 1 0 8 0 zombiepl 144 429 0 429 1 0 1 1 0 8 1 processpl 984 462 0 429 5 0 5 5 0 8 0 procpl 624 990 0 945 4 0 4 4 0 8 0 sosppl 128 5 0 5 1 0 1 1 0 8 1 sockpl 400 879 0 848 5 0 5 5 0 8 1 mcl64k 65536 7 0 0 1 0 1 1 0 8 0 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 4 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 4 0 0 1 0 1 1 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 164 0 0 20 0 20 20 0 8 0 mtagpl 80 23 0 0 1 0 1 1 0 8 0 mbufpl 256 288 0 0 18 0 18 18 0 8 0 bufpl 280 4747 0 174 327 0 327 327 0 8 0 anonpl 16 51085 0 36939 60 1 59 59 0 124 1 amapchunkpl 152 2596 0 2458 13 1 12 13 0 158 6 amappl16 192 1943 0 1152 40 0 40 40 0 8 0 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 116 0 113 2 1 1 1 0 8 0 amappl13 168 25 0 24 1 0 1 1 0 8 0 amappl12 160 4 0 3 1 0 1 1 0 8 0 amappl11 152 71 0 53 1 0 1 1 0 8 0 amappl10 144 17 0 13 1 0 1 1 0 8 0 amappl9 136 391 0 387 1 0 1 1 0 8 0 amappl8 128 299 0 283 1 0 1 1 0 8 0 amappl7 120 125 0 113 1 0 1 1 0 8 0 amappl6 112 29 0 24 1 0 1 1 0 8 0 amappl5 104 340 0 324 1 0 1 1 0 8 0 amappl4 96 510 0 477 2 1 1 2 0 8 0 amappl3 88 117 0 112 1 0 1 1 0 8 0 amappl2 80 2643 0 2565 3 1 2 3 0 8 0 amappl1 72 19893 0 19436 25 15 10 20 0 8 0 amappl 80 1236 0 1190 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 9 0 2 1 0 1 1 0 8 0 uaddrrnd 24 448 0 431 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 448 0 431 1 0 1 1 0 8 0 vmmpekpl 168 7428 0 7397 2 0 2 2 0 8 0 vmmpepl 168 60696 0 58672 107 10 97 103 0 357 9 vmsppl 368 447 0 431 2 0 2 2 0 8 0 pdppl 4096 904 0 862 6 0 6 6 0 8 0 pvpl 32 176191 0 158316 150 0 150 150 0 265 5 pmappl 232 447 0 431 3 1 2 2 0 8 1 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 178 0 3 5 0 5 5 0 8 0