panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806a2f8e00+16 0x0!=0x6c922d14e7b19fa6 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *305911 46380 0 0x2 0x4000000 0 syz-fuzzer 343930 64763 0 0x14000 0x200 1 softnet 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(ffffffff828ce6d0,1) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(1,1) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 m_getuio(ffff800020ea8318,0,41d3,ffff800020ea8498) at m_getuio+0xe4 sys/kern/uipc_socket.c:587 sosend(fffffd806eaede18,0,ffff800020ea8498,0,0,80) at sosend+0x54e sys/kern/uipc_socket.c:542 dofilewritev(ffff800020dd7b30,6,ffff800020ea8498,0,ffff800020ea8580) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff800020dd7b30,ffff800020ea8530,ffff800020ea8580) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020ea8600) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020ea8600) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xc0003b5400, count: 4 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 0xfffffd806a2f8e00+16 0x0!=0x6c922d14e7b19fa6 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(ffffffff828ce6d0,1) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(1,1) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 m_getuio(ffff800020ea8318,0,41d3,ffff800020ea8498) at m_getuio+0xe4 sys/kern/uipc_socket.c:587 sosend(fffffd806eaede18,0,ffff800020ea8498,0,0,80) at sosend+0x54e sys/kern/uipc_socket.c:542 dofilewritev(ffff800020dd7b30,6,ffff800020ea8498,0,ffff800020ea8580) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff800020dd7b30,ffff800020ea8530,ffff800020ea8580) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020ea8600) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020ea8600) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xc0003b5400, count: -11 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800020ea8040 rbx 0xffff800020ea80f0 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffff800020ea8000 r9 0xffffffff814bc41f kprintf+0x16f r10 0x1 r11 0xa3b498bdbbd2f78c r12 0x3000000008 r13 0xffff800020ea8050 r14 0x100 r15 0x1 rip 0xffffffff81c991c8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020ea8030 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-fuzzer) pid=305911 stat=onproc flags process=2 proc=4000000 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020dd6280,0xffff800020dd7160 process=0xffff8000ffffd3b0 user=0xffff800020ea3000, vmspace=0xfffffd806e8fb008 estcpu=0, cpticks=1, pctcpu=0.24 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 95280 277958 46380 0 3 0x2 biowait syz-executor.1 63354 41389 46380 0 3 0x82 piperd syz-executor.0 46380 173669 52839 0 3 0x82 thrsleep syz-fuzzer 46380 305700 52839 0 3 0x4000082 nanosleep syz-fuzzer 46380 350918 52839 0 3 0x4000082 thrsleep syz-fuzzer 46380 177666 52839 0 3 0x4000082 thrsleep syz-fuzzer 46380 451730 52839 0 3 0x4000082 nanosleep syz-fuzzer 46380 36146 52839 0 3 0x4000082 thrsleep syz-fuzzer 46380 220494 52839 0 3 0x4000082 thrsleep syz-fuzzer *46380 305911 52839 0 7 0x4000002 syz-fuzzer 52839 297411 16143 0 3 0x10008a pause ksh 16143 502251 29458 0 3 0x92 select sshd 64870 449416 1 0 3 0x100083 ttyin getty 29458 129599 1 0 3 0x80 select sshd 42101 520225 66522 74 3 0x100092 bpf pflogd 66522 96762 1 0 3 0x80 netio pflogd 63340 346353 27308 73 3 0x100090 kqread syslogd 27308 247255 1 0 3 0x100082 netio syslogd 67635 488555 1 77 3 0x100090 poll dhclient 94382 190269 1 0 3 0x80 poll dhclient 70235 247344 0 0 3 0x14200 bored smr 4515 377378 0 0 3 0x14200 pgzero zerothread 31379 129235 0 0 3 0x14200 aiodoned aiodoned 69317 508559 0 0 3 0x14200 syncer update 85003 371485 0 0 3 0x14200 cleaner cleaner 22301 276672 0 0 3 0x14200 reaper reaper 27326 159669 0 0 3 0x14200 pgdaemon pagedaemon 80577 135584 0 0 3 0x14200 bored crynlk 23637 167167 0 0 3 0x14200 bored crypto 59044 512612 0 0 3 0x40014200 acpi0 acpi0 80242 522377 0 0 3 0x40014200 idle1 64763 343930 0 0 7 0x14200 softnet 52799 64040 0 0 3 0x14200 bored systqmp 51631 459262 0 0 3 0x14200 bored systq 47586 276866 0 0 3 0x40014200 bored softclock 26011 247854 0 0 3 0x40014200 idle0 1 187286 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks CPU 1: exclusive sched_lock &sched_lock r = 0 (0xffffffff8292b170) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #1 sched_idle+0x19e sys/kern/kern_sched.c:162 #2 proc_trampoline+0x1c Process 95280 (syz-executor.1) thread 0xffff800020e8f8c8 (277958) exclusive rrwlock inode r = 0 (0xfffffd806ca2c4d8) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 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:603 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:575 #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:1329 #8 ufs_lookup+0x14b7 sys/ufs/ufs/ufs_lookup.c:487 #9 VOP_LOOKUP+0x5b sys/kern/vfs_vops.c:90 #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:1853 #13 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #13 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806ca2c808) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 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:603 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:575 #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:1853 #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 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9474 6397K 6527K 78643K 10595 0 pcb 13 8K 8K 78643K 19 0 rtable 99 3K 3K 78643K 209 0 ifaddr 43 10K 10K 78643K 48 0 counters 43 33K 33K 78643K 43 0 ioctlops 0 0K 4K 78643K 1477 0 iov 0 0K 0K 78643K 2 0 mount 1 1K 1K 78643K 1 0 vnodes 1221 77K 77K 78643K 1234 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 7 0K 0K 78643K 8 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1824 197K 290K 78643K 13058 0 file desc 4 9K 25K 78643K 65 0 proc 59 63K 95K 78643K 438 0 subproc 32 2K 2K 78643K 34 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 in_multi 29 1K 2K 78643K 39 0 ether_multi 1 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 61 281K 281K 78643K 61 0 exec 0 0K 1K 78643K 209 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 152 26K 26K 78643K 1160 0 UVM aobj 3 2K 2K 78643K 4 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 NDP 6 0K 0K 78643K 11 0 temp 67 3859K 3923K 78643K 2082 0 kqueue 3 4K 14K 78643K 23 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 6 0 0 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 88 20 0 18 1 0 1 1 0 8 0 rtentry 112 49 0 8 2 0 2 2 0 8 0 unpcb 120 25 0 15 1 0 1 1 0 8 0 syncache 272 4 0 4 1 1 0 1 0 8 0 tcpqe 32 335 0 335 1 1 0 1 0 8 0 tcpcb 592 18 0 7 1 0 1 1 0 8 0 inpcb 296 75 0 68 2 0 2 2 0 8 1 nd6 48 7 0 3 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 14 0 5 1 0 1 1 0 8 0 pfstkey 112 14 0 5 1 0 1 1 0 8 0 pfstate 328 14 0 5 2 0 2 2 0 8 0 pfrule 1360 22 0 18 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 212 0 40 13 0 13 13 0 8 0 art_table 32 213 0 40 2 0 2 2 0 8 0 art_node 16 48 0 10 1 0 1 1 0 8 0 semapl 112 6 0 1 1 0 1 1 0 8 0 shmpl 112 1 0 1 1 1 0 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1462 0 58 88 0 88 88 0 8 0 ffsino 272 1462 0 58 94 0 94 94 0 8 0 nchpl 144 1725 0 120 60 0 60 60 0 8 0 uvmvnodes 72 1514 0 0 28 0 28 28 0 8 0 vnodes 208 1514 0 0 80 0 80 80 0 8 0 namei 1024 4600 0 4600 1 0 1 1 0 8 1 percpumem 16 32 0 0 1 0 1 1 0 8 0 scxspl 200 5125 0 5124 8 7 1 7 0 8 0 plimitpl 152 15 0 7 1 0 1 1 0 8 0 sigapl 424 280 0 250 4 0 4 4 0 8 0 futexpl 56 351 0 351 1 0 1 1 0 8 1 knotepl 112 87 0 67 1 0 1 1 0 8 0 kqueuepl 152 30 0 28 1 0 1 1 0 8 0 pipepl 304 76 0 65 1 0 1 1 0 8 0 fdescpl 496 265 0 250 3 0 3 3 0 8 0 filepl 152 1344 0 1242 5 0 5 5 0 8 1 lockfpl 104 7 0 6 1 0 1 1 0 8 0 lockfspl 48 4 0 3 1 0 1 1 0 8 0 sessionpl 120 18 0 7 1 0 1 1 0 8 0 pgrppl 48 18 0 7 1 0 1 1 0 8 0 ucredpl 96 137 0 128 1 0 1 1 0 8 0 zombiepl 144 250 0 250 1 0 1 1 0 8 1 processpl 1008 280 0 250 5 0 5 5 0 8 1 procpl 632 360 0 323 5 1 4 5 0 8 0 sockpl 400 120 0 101 4 1 3 3 0 8 1 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 189 0 0 23 0 23 23 0 8 0 mtagpl 96 1 0 0 1 0 1 1 0 8 0 mbufpl 256 211 0 0 13 0 13 13 0 8 0 bufpl 280 3345 0 127 230 0 230 230 0 8 0 anonpl 16 39792 0 24460 64 1 63 63 0 124 0 amapchunkpl 152 1410 0 1116 14 1 13 14 0 158 0 amappl16 192 894 0 228 34 0 34 34 0 8 0 amappl15 184 9 0 7 1 0 1 1 0 8 0 amappl14 176 4 0 2 2 1 1 1 0 8 0 amappl13 168 50 0 45 1 0 1 1 0 8 0 amappl12 160 44 0 39 1 0 1 1 0 8 0 amappl11 152 54 0 38 1 0 1 1 0 8 0 amappl10 144 16 0 14 1 0 1 1 0 8 0 amappl9 136 371 0 369 1 0 1 1 0 8 0 amappl8 128 351 0 315 2 0 2 2 0 8 0 amappl7 120 117 0 103 1 0 1 1 0 8 0 amappl6 112 33 0 25 1 0 1 1 0 8 0 amappl5 104 152 0 137 1 0 1 1 0 8 0 amappl4 96 506 0 475 1 0 1 1 0 8 0 amappl3 88 139 0 129 1 0 1 1 0 8 0 amappl2 80 1173 0 1113 2 0 2 2 0 8 0 amappl1 72 16206 0 15787 24 14 10 18 0 8 0 amappl 80 650 0 573 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 3 0 1 1 0 1 1 0 8 0 uaddrrnd 24 265 0 250 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 265 0 250 1 0 1 1 0 8 0 vmmpekpl 168 6137 0 6102 2 0 2 2 0 8 0 vmmpepl 168 39812 0 38050 112 23 89 104 0 357 5 vmsppl 368 264 0 250 2 0 2 2 0 8 0 pdppl 4096 537 0 500 6 0 6 6 0 8 1 pvpl 32 144771 0 126389 157 2 155 157 0 265 1 pmappl 232 264 0 250 2 1 1 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 255 0 5 8 0 8 8 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 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(ffffffff828ce6d0,1) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(1,1) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 m_getuio(ffff800020ea8318,0,41d3,ffff800020ea8498) at m_getuio+0xe4 sys/kern/uipc_socket.c:587 sosend(fffffd806eaede18,0,ffff800020ea8498,0,0,80) at sosend+0x54e sys/kern/uipc_socket.c:542 dofilewritev(ffff800020dd7b30,6,ffff800020ea8498,0,ffff800020ea8580) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff800020dd7b30,ffff800020ea8530,ffff800020ea8580) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020ea8600) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020ea8600) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xc0003b5400, count: -11 ddb{0}> machine ddbcpu 1