y7šs?hJ¬µÐó¦òdæùŒµ»nÚzÒ™„“òñÙñpanic: kernel diagnostic assertion "cpipe->pipe_buffer.cnt == 0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/sys_pipe.c", line 223 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 359454 18130 0 0 0x4000000 1 syz-executor.0 *129759 18130 0 0 0x4000000 0K syz-executor.0 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:212 __assert(ffffffff81fac4df,ffffffff81f97e38,df,ffffffff81f4ba54) at __assert+0x2e sys/kern/subr_prf.c:159 pipespace(fffffd806f9e0628,10000) at pipespace+0x18f sys/kern/sys_pipe.c:219 pipe_write(fffffd8066777e60,ffff800023c5bc98,0) at pipe_write+0x973 sys/kern/sys_pipe.c:472 dofilewritev(ffff800020b5e018,4,ffff800023c5bc98,0,ffff800023c5bda0) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff800020b5e018,ffff800023c5bd38,ffff800023c5bda0) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800023c5be10) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800023c5be10) at syscall+0x552 sys/arch/amd64/amd64/trap.c:554 Xsyscall(6,0,c,0,3,b65a94971b0) at Xsyscall+0x128 end of kernel end trace frame: 0xb67bbf44840, count: 6 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 kernel diagnostic assertion "cpipe->pipe_buffer.cnt == 0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/sys_pipe.c", line 223 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:212 __assert(ffffffff81fac4df,ffffffff81f97e38,df,ffffffff81f4ba54) at __assert+0x2e sys/kern/subr_prf.c:159 pipespace(fffffd806f9e0628,10000) at pipespace+0x18f sys/kern/sys_pipe.c:219 pipe_write(fffffd8066777e60,ffff800023c5bc98,0) at pipe_write+0x973 sys/kern/sys_pipe.c:472 dofilewritev(ffff800020b5e018,4,ffff800023c5bc98,0,ffff800023c5bda0) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff800020b5e018,ffff800023c5bd38,ffff800023c5bda0) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800023c5be10) at syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800023c5be10) at syscall+0x552 sys/arch/amd64/amd64/trap.c:554 Xsyscall(6,0,c,0,3,b65a94971b0) at Xsyscall+0x128 end of kernel end trace frame: 0xb67bbf44840, count: -9 ddb{0}> show registers rdi 0xffffffff81c0e2c7 db_enter+0x17 rsi 0x3a45 __ALIGN_SIZE+0x2a45 rbp 0xffff800023c5ba10 rbx 0xffff800023c5bac0 rdx 0x3a46 __ALIGN_SIZE+0x2a46 rcx 0xffff800020ffc000 rax 0xffff800020ffc000 r8 0xffffffff8129f2b3 kprintf+0x173 r9 0x1 r10 0x25 r11 0xfb45e6d371bd18e7 r12 0x3000000008 r13 0xffff800023c5ba20 r14 0x100 r15 0x1 rip 0xffffffff81c0e2c8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800023c5ba00 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.0) pid=129759 stat=onproc flags process=0 proc=4000000 pri=16, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020b5f650,0xffffffff823aadc0 process=0xffff800020b7d500 user=0xffff800023c56000, vmspace=0xfffffd807f00bcf0 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 18130 130480 79650 0 2 0 syz-executor.0 18130 359454 79650 0 7 0x4000000 syz-executor.0 18130 494272 79650 0 2 0x4000000 syz-executor.0 *18130 129759 79650 0 7 0x4000000 syz-executor.0 73107 400443 0 0 3 0x14200 bored sosplice 69401 314155 88257 0 3 0x82 piperd syz-executor.1 79650 178481 88257 0 3 0x82 nanosleep syz-executor.0 88257 48018 88635 0 3 0x82 thrsleep syz-fuzzer 88257 58848 88635 0 2 0x4000482 syz-fuzzer 88257 467048 88635 0 3 0x4000082 thrsleep syz-fuzzer 88257 345718 88635 0 3 0x4000082 kqread syz-fuzzer 88257 302513 88635 0 3 0x4000082 thrsleep syz-fuzzer 88257 190545 88635 0 3 0x4000082 thrsleep syz-fuzzer 88257 340467 88635 0 3 0x4000082 thrsleep syz-fuzzer 88257 361738 88635 0 2 0x4000482 syz-fuzzer 88257 179051 88635 0 3 0x4000082 thrsleep syz-fuzzer 88257 518058 88635 0 3 0x4000082 thrsleep syz-fuzzer 88635 149469 53775 0 3 0x10008a pause ksh 53775 381572 62005 0 3 0x92 select sshd 82923 490643 1 0 3 0x100083 ttyin getty 62005 433043 1 0 3 0x80 select sshd 35104 122552 82461 74 3 0x100092 bpf pflogd 82461 503176 1 0 3 0x80 netio pflogd 60119 453616 61298 73 3 0x100090 kqread syslogd 61298 202050 1 0 3 0x100082 netio syslogd 96699 392212 1 77 3 0x100090 poll dhclient 29429 74321 1 0 3 0x80 poll dhclient 1310 430142 0 0 3 0x14200 pgzero zerothread 71145 9402 0 0 3 0x14200 aiodoned aiodoned 92181 25062 0 0 3 0x14200 syncer update 82617 449146 0 0 3 0x14200 cleaner cleaner 10342 372877 0 0 3 0x14200 reaper reaper 50353 237527 0 0 3 0x14200 pgdaemon pagedaemon 71810 435368 0 0 3 0x14200 bored crynlk 1847 78038 0 0 3 0x14200 bored crypto 7879 496017 0 0 3 0x40014200 acpi0 acpi0 96521 147774 0 0 3 0x40014200 idle1 48550 31349 0 0 3 0x14200 bored softnet 87452 197020 0 0 3 0x14200 bored systqmp 73096 113556 0 0 3 0x14200 bored systq 42048 270199 0 0 3 0x40014200 bored softclock 9110 223881 0 0 3 0x40014200 idle0 64715 355754 0 0 3 0x14200 bored smr 1 199811 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 18130 (syz-executor.0) thread 0xffff800020b5e018 (129759) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff823a5968) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 __mp_acquire_count+0x51 sys/kern/kern_lock.c:227 #2 mi_switch+0x38f sys/kern/sched_bsd.c:440 #3 sleep_finish+0x113 sys/kern/kern_synch.c:373 #4 tsleep+0x198 sleep_finish_timeout sys/kern/kern_synch.c:397 [inline] #4 tsleep+0x198 sleep_finish_all sys/kern/kern_synch.c:183 [inline] #4 tsleep+0x198 sys/kern/kern_synch.c:152 #5 pipe_write+0x8f0 pipelock sys/kern/sys_pipe.c:286 [inline] #5 pipe_write+0x8f0 sys/kern/sys_pipe.c:471 #6 dofilewritev+0x1ac sys/kern/sys_generic.c:364 #7 sys_write+0x83 sys/kern/sys_generic.c:284 #8 syscall+0x552 mi_syscall sys/sys/syscall_mi.h:92 [inline] #8 syscall+0x552 sys/arch/amd64/amd64/trap.c:554 #9 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9479 6392K 6842K 78643K 11116 0 0 pcb 25 9K 10K 78643K 137 0 0 rtable 83 2K 3K 78643K 235 0 0 ifaddr 39 10K 11K 78643K 59 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1476 0 0 iov 0 0K 12K 78643K 20 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1216 76K 77K 78643K 1418 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 9K 78643K 6 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 26 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 358 0 0 sigio 0 0K 0K 78643K 6 0 0 proc 53 50K 71K 78643K 455 0 0 subproc 32 2K 2K 78643K 34 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 0K 78643K 19 0 0 in_multi 22 1K 2K 78643K 34 0 0 ether_multi 1 0K 0K 78643K 1 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 42 185K 185K 78643K 42 0 0 exec 0 0K 1K 78643K 227 0 0 pagedep 1 8K 8K 78643K 1 0 0 inodedep 1 32K 32K 78643K 1 0 0 newblk 1 0K 0K 78643K 1 0 0 VM swap 7 26K 26K 78643K 7 0 0 UVM amap 96 21K 21K 78643K 2047 0 0 UVM aobj 18 2K 2K 78643K 18 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 0K 78643K 18 0 0 NDP 7 0K 0K 78643K 16 0 0 temp 108 2739K 2803K 78643K 4210 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 6 0 2 1 0 1 1 0 8 0 inpcbpl 280 142 0 135 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 45 0 12 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 5924 0 5924 2 2 0 1 0 8 0 tcpcb 544 45 0 41 1 0 1 1 0 8 0 nd6 48 6 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 13 0 3 1 0 1 1 0 8 0 pfstkey 112 13 0 3 1 0 1 1 0 8 0 pfstate 328 13 0 3 1 0 1 1 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 256 188 0 44 12 0 12 12 0 8 2 art_table 32 189 0 44 2 0 2 2 0 8 0 art_node 16 44 0 14 1 0 1 1 0 8 0 sysvmsgpl 40 2 0 0 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 24 0 14 1 0 1 1 0 8 0 shmpl 112 16 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 2012 0 583 47 0 47 47 0 8 0 ffsino 272 2012 0 583 96 0 96 96 0 8 0 nchpl 144 2899 0 1251 62 0 62 62 0 8 0 uvmvnodes 72 2192 0 0 40 0 40 40 0 8 0 vnodes 200 2192 0 0 116 0 116 116 0 8 0 namei 1024 7954 0 7954 3 2 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 7162 0 7162 8 7 1 6 0 8 1 plimitpl 152 28 0 20 1 0 1 1 0 8 0 sigapl 432 558 0 543 3 1 2 3 0 8 0 futexpl 56 4735 0 4735 1 0 1 1 0 8 1 knotepl 112 86 0 67 1 0 1 1 0 8 0 kqueuepl 104 47 0 45 1 0 1 1 0 8 0 pipepl 112 232 0 211 2 1 1 1 0 8 0 fdescpl 488 559 0 543 3 0 3 3 0 8 0 filepl 152 3070 0 2966 6 1 5 5 0 8 0 lockfpl 104 86 0 85 2 1 1 1 0 8 0 lockfspl 48 39 0 38 2 1 1 1 0 8 0 sessionpl 112 18 0 7 1 0 1 1 0 8 0 pgrppl 48 26 0 15 1 0 1 1 0 8 0 ucredpl 96 269 0 260 1 0 1 1 0 8 0 zombiepl 144 543 0 543 3 2 1 1 0 8 1 processpl 896 575 0 543 4 0 4 4 0 8 0 procpl 632 1167 0 1123 5 1 4 5 0 8 0 srpgc 64 2 0 2 1 0 1 1 0 8 1 sosppl 128 2 0 2 1 1 0 1 0 8 0 sockpl 384 248 0 229 4 1 3 3 0 8 1 mcl64k 65536 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 4 0 0 1 0 1 1 0 8 0 mcl2k 2048 118 0 0 14 0 14 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 145 0 0 9 0 9 9 0 8 0 bufpl 256 6315 0 1167 322 0 322 322 0 8 0 anonpl 16 53745 0 43268 45 2 43 43 0 125 0 amapchunkpl 152 2523 0 2427 7 2 5 6 0 158 0 amappl16 192 2096 0 1528 29 0 29 29 0 8 0 amappl15 184 175 0 173 1 0 1 1 0 8 0 amappl14 176 51 0 45 1 0 1 1 0 8 0 amappl13 168 14 0 13 2 1 1 1 0 8 0 amappl12 160 13 0 12 1 0 1 1 0 8 0 amappl11 152 58 0 43 1 0 1 1 0 8 0 amappl10 144 76 0 70 1 0 1 1 0 8 0 amappl9 136 752 0 747 1 0 1 1 0 8 0 amappl8 128 301 0 283 1 0 1 1 0 8 0 amappl7 120 43 0 38 1 0 1 1 0 8 0 amappl6 112 63 0 55 1 0 1 1 0 8 0 amappl5 104 135 0 120 1 0 1 1 0 8 0 amappl4 96 828 0 800 2 1 1 2 0 8 0 amappl3 88 187 0 177 1 0 1 1 0 8 0 amappl2 80 3687 0 3615 4 2 2 3 0 8 0 amappl1 72 21582 0 21138 26 16 10 20 0 8 0 amappl 80 1423 0 1385 1 0 1 1 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 dma64 64 259 0 259 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 17 0 17 1 1 0 1 0 8 0 aobjpl 64 17 0 0 1 0 1 1 0 8 0 uaddrrnd 24 559 0 543 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 559 0 543 1 0 1 1 0 8 0 vmmpekpl 168 7951 0 7922 2 0 2 2 0 8 0 vmmpepl 168 73229 0 71529 123 42 81 92 0 357 2 vmsppl 368 558 0 543 2 0 2 2 0 8 0 pdppl 4096 1125 0 1086 7 1 6 6 0 8 0 pvpl 32 185993 0 172345 134 18 116 116 0 265 5 pmappl 232 558 0 543 2 1 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 477 0 6 14 0 14 14 0 8 0