login: panic: kernel diagnostic assertion "len >= 0 && !M_READONLY(m)" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/uipc_mbuf.c", line 1384 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *128859 71338 0 0 0 1K syz-executor.0 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff82572ea9) at panic+0x177 sys/kern/subr_prf.c:202 __assert(ffffffff825e9d35,ffffffff8255b72b,568,ffffffff82589a8e) at __assert+0x25 sys/kern/subr_prf.c:161 m_align(fffffd806e813100,ffffffd7) at m_align+0x1a0 sys/kern/uipc_mbuf.c:1385 bpf_movein(ffff800021214a70,ffff800000b96600,ffff8000212147d8,ffff8000212146d8) at bpf_movein+0x25e sys/net/bpf.c:228 bpfwrite(31700,ffff800021214a70,1) at bpfwrite+0x169 sys/net/bpf.c:648 spec_write(ffff8000212148d0) at spec_write+0xd4 sys/kern/spec_vnops.c:309 VOP_WRITE(fffffd806a948da0,ffff800021214a70,1,fffffd807f7d8840) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245 vn_write(fffffd807ea7aab8,ffff800021214a70,1) at vn_write+0x1a1 sys/kern/vfs_vnops.c:414 dofilewritev(ffff8000ffff4540,3,ffff800021214a70,1,ffff800021214b70) at dofilewritev+0x19c sys/kern/sys_generic.c:380 sys_pad_pwrite(ffff8000ffff4540,ffff800021214b18,ffff800021214b70) at sys_pad_pwrite+0x92 sys_pwrite sys/kern/vfs_syscalls.c:3354 [inline] sys_pad_pwrite(ffff8000ffff4540,ffff800021214b18,ffff800021214b70) at sys_pad_pwrite+0x92 sys/kern/vfs_syscalls.c:3426 syscall(ffff800021214be0) at syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800021214be0) at syscall+0x489 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc3150, count: 2 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 *cpu1: kernel diagnostic assertion "len >= 0 && !M_READONLY(m)" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/uipc_mbuf.c", line 1384 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff82572ea9) at panic+0x177 sys/kern/subr_prf.c:202 __assert(ffffffff825e9d35,ffffffff8255b72b,568,ffffffff82589a8e) at __assert+0x25 sys/kern/subr_prf.c:161 m_align(fffffd806e813100,ffffffd7) at m_align+0x1a0 sys/kern/uipc_mbuf.c:1385 bpf_movein(ffff800021214a70,ffff800000b96600,ffff8000212147d8,ffff8000212146d8) at bpf_movein+0x25e sys/net/bpf.c:228 bpfwrite(31700,ffff800021214a70,1) at bpfwrite+0x169 sys/net/bpf.c:648 spec_write(ffff8000212148d0) at spec_write+0xd4 sys/kern/spec_vnops.c:309 VOP_WRITE(fffffd806a948da0,ffff800021214a70,1,fffffd807f7d8840) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245 vn_write(fffffd807ea7aab8,ffff800021214a70,1) at vn_write+0x1a1 sys/kern/vfs_vnops.c:414 dofilewritev(ffff8000ffff4540,3,ffff800021214a70,1,ffff800021214b70) at dofilewritev+0x19c sys/kern/sys_generic.c:380 sys_pad_pwrite(ffff8000ffff4540,ffff800021214b18,ffff800021214b70) at sys_pad_pwrite+0x92 sys_pwrite sys/kern/vfs_syscalls.c:3354 [inline] sys_pad_pwrite(ffff8000ffff4540,ffff800021214b18,ffff800021214b70) at sys_pad_pwrite+0x92 sys/kern/vfs_syscalls.c:3426 syscall(ffff800021214be0) at syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800021214be0) at syscall+0x489 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc3150, count: -13 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff8000212144f0 rbx 0xffff800020ce9bff rdx 0x3fd rcx 0 rax 0x94 r8 0x101010101010101 r9 0x8080808080808080 r10 0x246270c04659fee4 r11 0x4d39ca11d52c2546 r12 0xffff800020ce9a00 r13 0 r14 0 r15 0x1 rip 0xffffffff824d4738 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000212144e0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=128859 stat=onproc flags process=0 proc=0 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffff5500,0xffffffff82b60628 process=0xffff8000ffffb1e8 user=0xffff80002120f000, vmspace=0xfffffd807efff000 estcpu=9, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND *71338 128859 8776 0 7 0 syz-executor.0 8776 319598 24041 0 3 0x82 nanoslp syz-executor.0 24041 446271 90132 0 3 0x82 kqread syz-execprog 24041 412379 90132 0 3 0x4000082 nanoslp syz-execprog 24041 297668 90132 0 3 0x4000082 thrsleep syz-execprog 24041 289933 90132 0 3 0x4000082 nanoslp syz-execprog 24041 326783 90132 0 3 0x4000082 thrsleep syz-execprog 24041 337653 90132 0 3 0x4000082 thrsleep syz-execprog 24041 303664 90132 0 3 0x4000082 thrsleep syz-execprog 24041 459275 90132 0 3 0x4000082 thrsleep syz-execprog 90132 200276 10874 0 3 0x10008a sigsusp ksh 10874 176032 61156 0 3 0x9a poll sshd 46011 345097 1 0 3 0x100083 ttyin getty 61156 321120 1 0 3 0x88 poll sshd 51699 466888 50428 74 3 0x100092 bpf pflogd 50428 433222 1 0 3 0x80 netio pflogd 35992 85027 22318 73 3 0x100090 kqread syslogd 22318 346604 1 0 3 0x100082 netio syslogd 14384 40408 1 0 3 0x100080 kqread resolvd 51858 65616 15173 77 3 0x100092 kqread dhcpleased 41830 357272 15173 77 3 0x100092 kqread dhcpleased 15173 330039 1 0 3 0x80 kqread dhcpleased 59932 13744 0 0 3 0x14200 bored smr 82662 329463 0 0 3 0x14200 pgzero zerothread 32043 24617 0 0 3 0x14200 aiodoned aiodoned 50525 150612 0 0 3 0x14200 syncer update 32116 320689 0 0 3 0x14200 cleaner cleaner 89248 315483 0 0 3 0x14200 reaper reaper 91131 237695 0 0 3 0x14200 pgdaemon pagedaemon 67652 102271 0 0 3 0x14200 bored viomb 72021 245000 0 0 3 0x40014200 acpi0 acpi0 1359 426694 0 0 3 0x40014200 idle1 3499 401630 0 0 3 0x14200 bored softnet 58174 236455 0 0 3 0x14200 bored systqmp 39802 514759 0 0 3 0x14200 bored systq 47937 38840 0 0 3 0x40014200 bored softclock 27901 79716 0 0 7 0x40014200 idle0 1 368167 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 71338 (syz-executor.0) thread 0xffff8000ffff4540 (128859) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82b5a628) #0 witness_lock+0x44d #1 vn_write+0x42 sys/kern/vfs_vnops.c:399 #2 dofilewritev+0x19c sys/kern/sys_generic.c:380 #3 sys_pad_pwrite+0x92 sys_pwrite sys/kern/vfs_syscalls.c:3354 [inline] #3 sys_pad_pwrite+0x92 sys/kern/vfs_syscalls.c:3426 #4 syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] #4 syscall+0x489 sys/arch/amd64/amd64/trap.c:585 #5 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10157 6522K 6522K 78643K 11247 0 pcb 13 8K 8K 78643K 13 0 rtable 84 2K 3K 78643K 142 0 ifaddr 37 9K 9K 78643K 40 0 counters 42 33K 33K 78643K 42 0 ioctlops 0 0K 4K 78643K 1480 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 5 0 vnodes 1168 73K 73K 78643K 1181 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 1K 78643K 2 0 VM map 2 1K 1K 78643K 2 0 sem 2 0K 0K 78643K 2 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 4 9K 13K 78643K 21 0 proc 67 87K 99K 78643K 310 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 in_multi 22 1K 1K 78643K 22 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 25 122K 122K 78643K 25 0 exec 0 0K 2K 78643K 481 0 tdb 3 0K 0K 78643K 3 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 133 15K 15K 78643K 2463 0 UVM aobj 3 2K 2K 78643K 3 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 NDP 7 0K 0K 78643K 7 0 temp 29 4682K 4745K 78643K 3545 0 kqueue 10 14K 14K 78643K 10 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 plcache 128 22 0 0 1 0 1 1 0 8 0 rtpcb 120 19 0 16 1 0 1 1 0 8 0 rtentry 112 34 0 1 1 0 1 1 0 8 0 unpcb 136 35 0 20 1 0 1 1 0 8 0 syncache 296 5 0 5 2 1 1 1 0 8 1 tcpcb 736 8 0 5 1 0 1 1 0 8 0 arp 120 4 0 0 1 0 1 1 0 8 0 inpcb 304 36 0 30 1 0 1 1 0 8 0 nd6 48 3 0 0 1 0 1 1 0 8 0 pfosfp 40 1428 0 1005 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 10 0 2 1 0 1 1 0 8 0 pfstkey 112 10 0 2 1 0 1 1 0 8 0 pfstate 320 10 0 2 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 256 144 0 0 9 0 9 9 0 8 0 art_table 32 145 0 0 2 0 2 2 0 8 0 art_node 16 33 0 3 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1451 0 49 88 0 88 88 0 8 0 ffsino 272 1451 0 49 94 0 94 94 0 8 0 nchpl 144 1679 0 59 60 0 60 60 0 8 0 uvmvnodes 80 1462 0 0 30 0 30 30 0 8 0 vnodes 224 1462 0 0 86 0 86 86 0 8 0 namei 1024 5145 0 5145 3 1 2 2 0 8 2 percpumem 16 33 0 0 1 0 1 1 0 8 0 scxspl 216 5398 0 5398 10 6 4 8 0 8 4 plimitpl 152 17 0 9 1 0 1 1 0 8 0 sigapl 424 347 0 316 5 0 5 5 0 8 1 knotepl 112 56 0 0 2 0 2 2 0 8 0 kqueuepl 216 6 0 0 1 0 1 1 0 8 0 pipepl 336 106 0 99 2 1 1 1 0 8 0 fdescpl 496 333 0 316 4 0 4 4 0 8 1 filepl 152 1350 0 1279 4 0 4 4 0 8 1 lockfpl 104 6 0 4 1 0 1 1 0 8 0 lockfspl 48 4 0 2 1 0 1 1 0 8 0 sessionpl 144 19 0 9 1 0 1 1 0 8 0 pgrppl 48 19 0 9 1 0 1 1 0 8 0 ucredpl 96 69 0 57 1 0 1 1 0 8 0 zombiepl 144 316 0 316 2 1 1 1 0 8 1 processpl 1064 347 0 316 3 0 3 3 0 8 0 procpl 672 354 0 316 4 0 4 4 0 8 0 sockpl 480 90 0 66 5 1 4 4 0 8 0 mcl8k 8192 7 0 0 1 0 1 1 0 8 0 mcl4k 4096 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 57 0 0 8 0 8 8 0 8 0 mtagpl 96 2 0 0 1 0 1 1 0 8 0 mbufpl 256 120 0 0 7 0 7 7 0 8 0 bufpl 288 3563 0 144 245 0 245 245 0 8 0 anonpl 24 49055 0 45295 48 4 44 44 0 186 17 amapchunkpl 152 5067 0 4756 20 1 19 19 0 158 6 amappl16 200 148 0 86 5 0 5 5 0 8 1 amappl15 192 82 0 78 1 0 1 1 0 8 0 amappl14 184 4 0 3 2 1 1 1 0 8 0 amappl13 176 49 0 47 2 1 1 1 0 8 0 amappl12 168 6 0 5 2 1 1 1 0 8 0 amappl11 160 61 0 46 1 0 1 1 0 8 0 amappl10 152 29 0 26 1 0 1 1 0 8 0 amappl9 144 442 0 439 1 0 1 1 0 8 0 amappl8 136 432 0 411 2 0 2 2 0 8 0 amappl7 128 88 0 78 1 0 1 1 0 8 0 amappl6 120 184 0 166 2 0 2 2 0 8 1 amappl5 112 167 0 154 1 0 1 1 0 8 0 amappl4 104 699 0 676 2 0 2 2 0 8 0 amappl3 96 144 0 134 1 0 1 1 0 8 0 amappl2 88 474 0 430 3 0 3 3 0 8 1 amappl1 80 9676 0 9247 21 3 18 19 0 8 9 amappl 88 2129 0 2028 4 0 4 4 0 92 1 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 1 0 0 1 0 1 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 72 2 0 0 1 0 1 1 0 8 0 uaddrrnd 24 333 0 316 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 333 0 316 1 0 1 1 0 8 0 vmmpekpl 168 8098 0 8079 2 0 2 2 0 8 0 vmmpepl 168 31895 0 30759 94 3 91 91 0 357 41 vmsppl 368 332 0 316 3 0 3 3 0 8 1 rwobjpl 56 10812 0 8623 41 0 41 41 0 8 5 pdppl 4096 673 0 632 77 28 49 57 0 8 8 pvpl 32 216072 0 209373 249 4 245 245 0 265 186 pmappl 248 332 0 316 2 0 2 2 0 8 0 extentpl 40 58 0 38 1 0 1 1 0 8 0 phpool 112 548 0 33 15 0 15 15 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffffffff82994ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 acpicpu_idle() at acpicpu_idle+0x312 sys/dev/acpi/acpicpu.c:1206 sched_idle(ffffffff82994ff0) at sched_idle+0x417 sys/kern/kern_sched.c:178 end trace frame: 0x0, count: 10 ddb{0}> trace x86_ipi_db(ffffffff82994ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 acpicpu_idle() at acpicpu_idle+0x312 sys/dev/acpi/acpicpu.c:1206 sched_idle(ffffffff82994ff0) at sched_idle+0x417 sys/kern/kern_sched.c:178 end trace frame: 0x0, count: -5 ddb{0}> machine ddbcpu 1 Stopped at db_enter+0x18: addq $0x8,%rsp db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff82572ea9) at panic+0x177 sys/kern/subr_prf.c:202 __assert(ffffffff825e9d35,ffffffff8255b72b,568,ffffffff82589a8e) at __assert+0x25 sys/kern/subr_prf.c:161 m_align(fffffd806e813100,ffffffd7) at m_align+0x1a0 sys/kern/uipc_mbuf.c:1385 bpf_movein(ffff800021214a70,ffff800000b96600,ffff8000212147d8,ffff8000212146d8) at bpf_movein+0x25e sys/net/bpf.c:228 bpfwrite(31700,ffff800021214a70,1) at bpfwrite+0x169 sys/net/bpf.c:648 spec_write(ffff8000212148d0) at spec_write+0xd4 sys/kern/spec_vnops.c:309 VOP_WRITE(fffffd806a948da0,ffff800021214a70,1,fffffd807f7d8840) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245 vn_write(fffffd807ea7aab8,ffff800021214a70,1) at vn_write+0x1a1 sys/kern/vfs_vnops.c:414 dofilewritev(ffff8000ffff4540,3,ffff800021214a70,1,ffff800021214b70) at dofilewritev+0x19c sys/kern/sys_generic.c:380 sys_pad_pwrite(ffff8000ffff4540,ffff800021214b18,ffff800021214b70) at sys_pad_pwrite+0x92 sys_pwrite sys/kern/vfs_syscalls.c:3354 [inline] sys_pad_pwrite(ffff8000ffff4540,ffff800021214b18,ffff800021214b70) at sys_pad_pwrite+0x92 sys/kern/vfs_syscalls.c:3426 syscall(ffff800021214be0) at syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800021214be0) at syscall+0x489 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc3150, count: 2 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff82572ea9) at panic+0x177 sys/kern/subr_prf.c:202 __assert(ffffffff825e9d35,ffffffff8255b72b,568,ffffffff82589a8e) at __assert+0x25 sys/kern/subr_prf.c:161 m_align(fffffd806e813100,ffffffd7) at m_align+0x1a0 sys/kern/uipc_mbuf.c:1385 bpf_movein(ffff800021214a70,ffff800000b96600,ffff8000212147d8,ffff8000212146d8) at bpf_movein+0x25e sys/net/bpf.c:228 bpfwrite(31700,ffff800021214a70,1) at bpfwrite+0x169 sys/net/bpf.c:648 spec_write(ffff8000212148d0) at spec_write+0xd4 sys/kern/spec_vnops.c:309 VOP_WRITE(fffffd806a948da0,ffff800021214a70,1,fffffd807f7d8840) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245 vn_write(fffffd807ea7aab8,ffff800021214a70,1) at vn_write+0x1a1 sys/kern/vfs_vnops.c:414 dofilewritev(ffff8000ffff4540,3,ffff800021214a70,1,ffff800021214b70) at dofilewritev+0x19c sys/kern/sys_generic.c:380 sys_pad_pwrite(ffff8000ffff4540,ffff800021214b18,ffff800021214b70) at sys_pad_pwrite+0x92 sys_pwrite sys/kern/vfs_syscalls.c:3354 [inline] sys_pad_pwrite(ffff8000ffff4540,ffff800021214b18,ffff800021214b70) at sys_pad_pwrite+0x92 sys/kern/vfs_syscalls.c:3426 syscall(ffff800021214be0) at syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800021214be0) at syscall+0x489 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc3150, count: -13 ddb{1}>