login: panic: kernel diagnostic assertion "len >= 0 && !M_READONLY(m)" failed: file "/syzkaller/managers/main/kernel/sys/kern/uipc_mbuf.c", line 1384 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *510956 28877 0 0 0 0 syz-executor.0 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff8254be5b) at panic+0x161 sys/kern/subr_prf.c:202 __assert(ffffffff825bbf89,ffffffff825cdd9d,568,ffffffff8255ec6a) at __assert+0x25 sys/kern/subr_prf.c:161 m_align(fffffd806a885800,ffffffeb) at m_align+0x1a0 sys/kern/uipc_mbuf.c:1385 bpf_movein(ffff80002166bc18,ffff800000b8b400,ffff80002166b978,ffff80002166b878) at bpf_movein+0x25e sys/net/bpf.c:228 bpfwrite(21700,ffff80002166bc18,1) at bpfwrite+0x128 sys/net/bpf.c:648 spec_write(ffff80002166ba70) at spec_write+0xcb sys/kern/spec_vnops.c:309 VOP_WRITE(fffffd806a8b8080,ffff80002166bc18,1,fffffd807f7d8a20) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245 vn_write(fffffd806c6a2a60,ffff80002166bc18,0) at vn_write+0x152 sys/kern/vfs_vnops.c:414 dofilewritev(ffff8000216202a0,3,ffff80002166bc18,0,ffff80002166bd10) at dofilewritev+0x19c sys/kern/sys_generic.c:380 sys_write(ffff8000216202a0,ffff80002166bcb8,ffff80002166bd10) at sys_write+0x83 sys/kern/sys_generic.c:300 syscall(ffff80002166bd80) at syscall+0x44e sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffbd980, 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> ddb> set $lines = 0 ddb> set $maxwidth = 0 ddb> show panic *cpu0: kernel diagnostic assertion "len >= 0 && !M_READONLY(m)" failed: file "/syzkaller/managers/main/kernel/sys/kern/uipc_mbuf.c", line 1384 ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff8254be5b) at panic+0x161 sys/kern/subr_prf.c:202 __assert(ffffffff825bbf89,ffffffff825cdd9d,568,ffffffff8255ec6a) at __assert+0x25 sys/kern/subr_prf.c:161 m_align(fffffd806a885800,ffffffeb) at m_align+0x1a0 sys/kern/uipc_mbuf.c:1385 bpf_movein(ffff80002166bc18,ffff800000b8b400,ffff80002166b978,ffff80002166b878) at bpf_movein+0x25e sys/net/bpf.c:228 bpfwrite(21700,ffff80002166bc18,1) at bpfwrite+0x128 sys/net/bpf.c:648 spec_write(ffff80002166ba70) at spec_write+0xcb sys/kern/spec_vnops.c:309 VOP_WRITE(fffffd806a8b8080,ffff80002166bc18,1,fffffd807f7d8a20) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245 vn_write(fffffd806c6a2a60,ffff80002166bc18,0) at vn_write+0x152 sys/kern/vfs_vnops.c:414 dofilewritev(ffff8000216202a0,3,ffff80002166bc18,0,ffff80002166bd10) at dofilewritev+0x19c sys/kern/sys_generic.c:380 sys_write(ffff8000216202a0,ffff80002166bcb8,ffff80002166bd10) at sys_write+0x83 sys/kern/sys_generic.c:300 syscall(ffff80002166bd80) at syscall+0x44e sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffbd980, count: -13 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002166b6a0 rbx 0x30 rdx 0x3fd rcx 0 rax 0x8f r8 0x101010101010101 r9 0x8080808080808080 r10 0x92afae0624cfdeff r11 0xb278b595cce5f3c6 r12 0 r13 0xffffffeb r14 0 r15 0x1 rip 0xffffffff8172f728 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002166b690 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (syz-executor.0) pid=510956 stat=onproc flags process=0 proc=0 pri=52, usrpri=52, nice=20 forw=0xffffffffffffffff, list=0xffff800021621500,0xffffffff829b39d0 process=0xffff800021600fb8 user=0xffff800021666000, vmspace=0xfffffd807f018110 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND *28877 510956 32578 0 7 0 syz-executor.0 32578 143543 60038 0 3 0x82 nanoslp syz-executor.0 60038 46203 50094 0 3 0x82 thrsleep syz-execprog 60038 123721 50094 0 3 0x4000082 nanoslp syz-execprog 60038 503791 50094 0 3 0x4000082 thrsleep syz-execprog 60038 245610 50094 0 3 0x4000082 thrsleep syz-execprog 60038 195413 50094 0 3 0x4000082 thrsleep syz-execprog 60038 357517 50094 0 3 0x4000082 kqread syz-execprog 60038 443652 50094 0 3 0x4000082 thrsleep syz-execprog 60038 166136 50094 0 3 0x4000082 thrsleep syz-execprog 50094 468408 18808 0 3 0x10008a sigsusp ksh 18808 159956 40303 0 3 0x9a poll sshd 56604 339371 1 0 3 0x100083 ttyin getty 40303 312547 1 0 3 0x88 poll sshd 25070 466578 64692 73 3 0x100090 kqread syslogd 64692 127478 1 0 3 0x100082 netio syslogd 96270 486335 1 0 3 0x100080 kqread resolvd 78249 136022 66355 77 3 0x100092 kqread dhcpleased 9796 399321 66355 77 3 0x100092 kqread dhcpleased 66355 173263 1 0 3 0x80 kqread dhcpleased 45091 468021 0 0 3 0x14200 bored smr 33259 343491 0 0 2 0x14200 zerothread 97702 169935 0 0 3 0x14200 aiodoned aiodoned 81955 462145 0 0 3 0x14200 syncer update 63147 148107 0 0 3 0x14200 cleaner cleaner 31706 201527 0 0 3 0x14200 reaper reaper 81259 318273 0 0 3 0x14200 pgdaemon pagedaemon 50187 456114 0 0 3 0x14200 bored viomb 19461 73960 0 0 3 0x40014200 acpi0 acpi0 27539 362685 0 0 3 0x14200 bored softnet 40481 350573 0 0 3 0x14200 bored systqmp 29499 132671 0 0 3 0x14200 bored systq 19526 226822 0 0 3 0x40014200 bored softclock 48266 104693 0 0 3 0x40014200 idle0 1 308589 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10139 6448K 6448K 78643K 11229 0 pcb 13 8K 8K 78643K 13 0 rtable 84 2K 3K 78643K 146 0 ifaddr 32 8K 8K 78643K 32 0 counters 20 16K 16K 78643K 20 0 ioctlops 0 0K 2K 78643K 26 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1167 73K 73K 78643K 1180 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 0K 0K 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 3 8K 12K 78643K 18 0 proc 55 54K 63K 78643K 254 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 458 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 118 13K 13K 78643K 2204 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 6 0K 0K 78643K 6 0 temp 24 4674K 4737K 78643K 3378 0 kqueue 10 14K 14K 78643K 10 0 SYN cache 2 16K 16K 78643K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 23 0 20 1 0 1 1 0 8 0 rtentry 112 34 0 1 1 0 1 1 0 8 0 unpcb 136 33 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 88 4 0 0 1 0 1 1 0 8 0 inpcb 304 29 0 23 1 0 1 1 0 8 0 nd6 48 3 0 0 1 0 1 1 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 1442 0 48 88 0 88 88 0 8 0 ffsino 240 1442 0 48 82 0 82 82 0 8 0 nchpl 144 1670 0 57 60 0 60 60 0 8 0 uvmvnodes 80 1452 0 0 30 0 30 30 0 8 0 vnodes 224 1452 0 0 86 0 86 86 0 8 0 namei 1024 4916 0 4916 3 1 2 2 0 8 2 scxspl 216 5208 0 5208 10 9 1 8 0 8 1 plimitpl 152 16 0 9 1 0 1 1 0 8 0 sigapl 424 329 0 301 5 0 5 5 0 8 1 knotepl 112 191 0 161 2 0 2 2 0 8 0 kqueuepl 184 6 0 0 1 0 1 1 0 8 0 pipepl 304 103 0 96 2 1 1 1 0 8 0 fdescpl 432 316 0 301 3 0 3 3 0 8 1 filepl 120 1239 0 1173 3 0 3 3 0 8 0 lockfpl 104 7 0 4 1 0 1 1 0 8 0 lockfspl 48 5 0 2 1 0 1 1 0 8 0 sessionpl 144 18 0 9 1 0 1 1 0 8 0 pgrppl 48 18 0 9 1 0 1 1 0 8 0 ucredpl 96 64 0 54 1 0 1 1 0 8 0 zombiepl 144 301 0 301 2 1 1 1 0 8 1 processpl 1000 329 0 301 5 0 5 5 0 8 1 procpl 672 336 0 301 4 0 4 4 0 8 0 sockpl 448 85 0 63 3 0 3 3 0 8 0 mcl8k 8192 9 0 9 2 1 1 1 0 8 1 mcl4k 4096 5 0 5 2 1 1 1 0 8 1 mcl2k 2048 5334 0 5304 6 2 4 6 0 8 0 mtagpl 96 4 0 4 1 1 0 1 0 8 0 mbufpl 256 9822 0 9722 8 1 7 7 0 8 0 bufpl 288 3489 0 143 239 0 239 239 0 8 0 anonpl 24 47072 0 43709 45 3 42 42 0 188 18 amapchunkpl 152 4664 0 4393 19 1 18 18 0 158 6 amappl16 200 120 0 62 5 1 4 4 0 8 0 amappl15 192 78 0 74 1 0 1 1 0 8 0 amappl14 184 1 0 1 1 0 1 1 0 8 1 amappl13 176 51 0 47 2 1 1 1 0 8 0 amappl12 168 13 0 13 2 1 1 1 0 8 1 amappl11 160 46 0 36 1 0 1 1 0 8 0 amappl10 152 17 0 17 2 1 1 1 0 8 1 amappl9 144 377 0 374 1 0 1 1 0 8 0 amappl8 136 419 0 398 1 0 1 1 0 8 0 amappl7 128 79 0 73 1 0 1 1 0 8 0 amappl6 120 174 0 157 2 0 2 2 0 8 0 amappl5 112 276 0 266 1 0 1 1 0 8 0 amappl4 104 656 0 630 2 0 2 2 0 8 1 amappl3 96 142 0 130 1 0 1 1 0 8 0 amappl2 88 479 0 436 3 0 3 3 0 8 1 amappl1 80 9348 0 8947 21 3 18 18 0 8 9 amappl 88 1885 0 1797 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 24 316 0 301 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 316 0 301 1 0 1 1 0 8 0 vmmpekpl 168 7694 0 7677 1 0 1 1 0 8 0 vmmpepl 168 30754 0 29703 93 6 87 87 0 357 40 vmsppl 272 315 0 301 3 1 2 2 0 8 1 rwobjpl 24 10555 0 8431 17 0 17 17 0 8 1 pdppl 4096 638 0 602 74 22 52 52 0 8 16 pvpl 32 208761 0 202549 247 6 241 241 0 265 185 pmappl 216 315 0 301 2 0 2 2 0 8 1 extentpl 40 58 0 38 1 0 1 1 0 8 0 phpool 112 527 0 31 15 0 15 15 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff8254be5b) at panic+0x161 sys/kern/subr_prf.c:202 __assert(ffffffff825bbf89,ffffffff825cdd9d,568,ffffffff8255ec6a) at __assert+0x25 sys/kern/subr_prf.c:161 m_align(fffffd806a885800,ffffffeb) at m_align+0x1a0 sys/kern/uipc_mbuf.c:1385 bpf_movein(ffff80002166bc18,ffff800000b8b400,ffff80002166b978,ffff80002166b878) at bpf_movein+0x25e sys/net/bpf.c:228 bpfwrite(21700,ffff80002166bc18,1) at bpfwrite+0x128 sys/net/bpf.c:648 spec_write(ffff80002166ba70) at spec_write+0xcb sys/kern/spec_vnops.c:309 VOP_WRITE(fffffd806a8b8080,ffff80002166bc18,1,fffffd807f7d8a20) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245 vn_write(fffffd806c6a2a60,ffff80002166bc18,0) at vn_write+0x152 sys/kern/vfs_vnops.c:414 dofilewritev(ffff8000216202a0,3,ffff80002166bc18,0,ffff80002166bd10) at dofilewritev+0x19c sys/kern/sys_generic.c:380 sys_write(ffff8000216202a0,ffff80002166bcb8,ffff80002166bd10) at sys_write+0x83 sys/kern/sys_generic.c:300 syscall(ffff80002166bd80) at syscall+0x44e sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffbd980, count: -13 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:440 panic(ffffffff8254be5b) at panic+0x161 sys/kern/subr_prf.c:202 __assert(ffffffff825bbf89,ffffffff825cdd9d,568,ffffffff8255ec6a) at __assert+0x25 sys/kern/subr_prf.c:161 m_align(fffffd806a885800,ffffffeb) at m_align+0x1a0 sys/kern/uipc_mbuf.c:1385 bpf_movein(ffff80002166bc18,ffff800000b8b400,ffff80002166b978,ffff80002166b878) at bpf_movein+0x25e sys/net/bpf.c:228 bpfwrite(21700,ffff80002166bc18,1) at bpfwrite+0x128 sys/net/bpf.c:648 spec_write(ffff80002166ba70) at spec_write+0xcb sys/kern/spec_vnops.c:309 VOP_WRITE(fffffd806a8b8080,ffff80002166bc18,1,fffffd807f7d8a20) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245 vn_write(fffffd806c6a2a60,ffff80002166bc18,0) at vn_write+0x152 sys/kern/vfs_vnops.c:414 dofilewritev(ffff8000216202a0,3,ffff80002166bc18,0,ffff80002166bd10) at dofilewritev+0x19c sys/kern/sys_generic.c:380 sys_write(ffff8000216202a0,ffff80002166bcb8,ffff80002166bd10) at sys_write+0x83 sys/kern/sys_generic.c:300 syscall(ffff80002166bd80) at syscall+0x44e sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffbd980, count: -13 ddb>