panic: kernel diagnostic assertion "rn != NULL" failed: file "/syzkaller/managers/main/kernel/sys/net/pipex.c", line 459 Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83482c9a) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff834c213b,ffffffff8341da6c,1cb,ffffffff8347f631) at __assert+0x29 sys/kern/subr_prf.c:-1 pipex_unlink_session_locked(ffff80003c8ebaa0) at pipex_unlink_session_locked+0x429 pipex_destroy_all_sessions(ffff800001587800) at pipex_destroy_all_sessions+0xd9 pipex_rele_session sys/net/pipex.c:-1 [inline] pipex_destroy_all_sessions(ffff800001587800) at pipex_destroy_all_sessions+0xd9 sys/net/pipex.c:151 pppacclose(6381,1,2000,ffff80003a4dd4e0) at pppacclose+0x16f sys/net/if_pppx.c:1335 spec_close(ffff80002a75cec0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(ffffef806f6ac7e0,1,ffffef8007ffd618,ffff80003a4dd4e0) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(ffffef80697495a0,ffff80003a4dd4e0) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(ffffef80697495a0,ffff80003a4dd4e0) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621 fdrop(ffffef80697495a0,ffff80003a4dd4e0) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(ffffef80697495a0,ffff80003a4dd4e0) at closef+0x190 sys/kern/kern_descrip.c:1265 fdfree(ffff80003a4dd4e0) at fdfree+0x115 sys/kern/kern_descrip.c:1196 exit1(ffff80003a4dd4e0,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003a4dd4e0,ffff80002a75d220,ffff80002a75d170) at sys_exit+0x1a sys/kern/kern_exit.c:-1 end trace frame: 0xffff80002a75d210, count: 0 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 "rn != NULL" failed: file "/syzkaller/managers/main/kernel/sys/net/pipex.c", line 459 ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83482c9a) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff834c213b,ffffffff8341da6c,1cb,ffffffff8347f631) at __assert+0x29 sys/kern/subr_prf.c:-1 pipex_unlink_session_locked(ffff80003c8ebaa0) at pipex_unlink_session_locked+0x429 pipex_destroy_all_sessions(ffff800001587800) at pipex_destroy_all_sessions+0xd9 pipex_rele_session sys/net/pipex.c:-1 [inline] pipex_destroy_all_sessions(ffff800001587800) at pipex_destroy_all_sessions+0xd9 sys/net/pipex.c:151 pppacclose(6381,1,2000,ffff80003a4dd4e0) at pppacclose+0x16f sys/net/if_pppx.c:1335 spec_close(ffff80002a75cec0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(ffffef806f6ac7e0,1,ffffef8007ffd618,ffff80003a4dd4e0) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(ffffef80697495a0,ffff80003a4dd4e0) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(ffffef80697495a0,ffff80003a4dd4e0) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621 fdrop(ffffef80697495a0,ffff80003a4dd4e0) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(ffffef80697495a0,ffff80003a4dd4e0) at closef+0x190 sys/kern/kern_descrip.c:1265 fdfree(ffff80003a4dd4e0) at fdfree+0x115 sys/kern/kern_descrip.c:1196 exit1(ffff80003a4dd4e0,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003a4dd4e0,ffff80002a75d220,ffff80002a75d170) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80002a75d220) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80002a75d220) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7acb9a60f380, count: -16 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002a75cca0 rbx 0x1 rdx 0 rcx 0 rax 0xffff80003a4dd4e0 r8 0x101010101010101 r9 0x8080808080808080 r10 0xaecabdfbd721e745 r11 0x3e25f2a1a8ed98cd r12 0 r13 0 r14 0 r15 0x1 rip 0xffffffff831be5d5 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a75cc90 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb> show proc PROC (syz-executor) tid=185301 pid=545 tcnt=0 stat=onproc flags process=1008 proc=2000 runpri=32, usrpri=74, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0xffff80003a4dd4e0 scnt=-1 ecnt=1 forw=0xffffffffffffffff, list=0xffff80003a4dd248,0xffff80002a777248 process=0xffff80002a790d90 user=0xffff80002a758000, vmspace=0xffffef806c9ab5d8 estcpu=24, cpticks=7, pctcpu=0.1, user=0, sys=2, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 71376 467339 80271 0 2 0 syz-executor 71376 252216 80271 0 3 0x4000080 kqread syz-executor 30397 513347 12124 0 2 0 syz-executor 30397 127180 12124 0 3 0x4000080 fsleep syz-executor 38254 145519 66461 0 2 0 syz-executor 38254 359042 66461 0 2 0x4000000 syz-executor 58061 155628 92817 0 3 0x80 nanoslp syz-executor 58061 96920 92817 0 3 0x4000080 fifor syz-executor 58061 339971 92817 0 3 0x4000080 fsleep syz-executor 31531 178973 1 0 3 0x82 nanoslp getty 1149 52936 0 0 3 0x14280 nfsidl nfsio 4998 23825 0 0 3 0x14280 nfsidl nfsio 38173 237878 0 0 3 0x14280 nfsidl nfsio 44942 188591 0 0 3 0x14280 nfsidl nfsio 66324 261801 0 0 3 0x14280 nfsidl nfsio 17286 174348 0 0 3 0x14280 nfsidl nfsio 38716 462835 0 0 3 0x14280 nfsidl nfsio 39939 262747 0 0 3 0x14280 nfsidl nfsio 74724 44920 0 0 3 0x14280 nfsidl nfsio 89452 443762 0 0 3 0x14280 nfsidl nfsio 29985 470807 0 0 3 0x14280 nfsidl nfsio 91694 59881 0 0 3 0x14280 nfsidl nfsio 27484 177388 0 0 3 0x14280 nfsidl nfsio 25257 515106 0 0 3 0x14280 nfsidl nfsio 62211 88755 0 0 3 0x14280 nfsidl nfsio 40954 311083 0 0 3 0x14280 nfsidl nfsio 48136 343128 0 0 3 0x14280 nfsidl nfsio 56147 237985 0 0 3 0x14280 nfsidl nfsio 54067 425075 0 0 3 0x14280 nfsidl nfsio 62333 119397 0 0 3 0x14280 nfsidl nfsio 7719 41151 80853 0 3 0x82 nanoslp syz-executor 13578 481248 80853 0 3 0x82 piperd syz-executor 92817 212576 80853 0 3 0x82 nanoslp syz-executor 12124 196377 80853 0 3 0x82 nanoslp syz-executor 80271 36508 80853 0 3 0x82 nanoslp syz-executor 66461 53341 80853 0 3 0x82 nanoslp syz-executor 99576 361491 80853 0 3 0x82 piperd syz-executor 22651 460688 80853 0 3 0x82 piperd syz-executor 80853 264591 1 0 2 0x2 syz-executor 3498 376323 0 0 3 0x14200 bored smr 78650 290550 0 0 2 0x14200 zerothread 10980 458349 0 0 3 0x14200 aiodoned aiodoned 62098 458678 0 0 3 0x14200 syncer update 85319 412177 0 0 3 0x14200 cleaner cleaner 95074 34232 0 0 3 0x14200 reaper reaper 77508 215739 0 0 3 0x14200 pgdaemon pagedaemon 61329 6262 0 0 3 0x14200 bored viomb 37434 442824 0 0 3 0x40014200 acpi0 acpi0 47178 354117 0 0 3 0x14200 bored softnet0 4551 110109 0 0 3 0x14200 bored systqmp 42747 27365 0 0 3 0x14200 bored systq 19645 136688 0 0 3 0x40014200 tmoslp softclock 37040 338967 0 0 3 0x40014200 idle0 1 352517 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 11035 12111K 12268K 166960K 12471 0 pcb 18 13K 14K 166960K 164 0 rtable 191 7K 8K 166960K 421 0 pf 36 14K 20K 166960K 85 0 ifaddr 37 6K 7K 166960K 62 0 ifgroup 54 2K 2K 166960K 84 0 sysctl 3 1K 9K 166960K 10 0 counters 35 18K 18K 166960K 51 0 ioctlops 0 0K 4K 166960K 151 0 iov 0 0K 4K 166960K 4 0 mount 1 1K 1K 166960K 1 0 log 1 0K 0K 166960K 5 0 vnodes 1353 85K 85K 166960K 1676 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 6 0 VM map 2 1K 1K 166960K 2 0 sem 9 0K 0K 166960K 11 0 dirhash 12 2K 2K 166960K 21 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 14 53K 89K 166960K 379 0 sigio 0 0K 0K 166960K 7 0 proc 20 25K 83K 166960K 570 0 subproc 72 4K 4K 166960K 82 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 15 0 in_multi 83 6K 7K 166960K 119 0 ether_multi 1 0K 0K 166960K 2 0 mrt 0 0K 0K 166960K 9 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 79 360K 360K 166960K 79 0 exec 0 0K 1K 166960K 385 0 fusefs mount 1 32K 32K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 116 81K 165K 166960K 4867 0 UVM aobj 10 6K 6K 166960K 11 0 pinsyscall 17 34K 92K 166960K 1492 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 12 0 NDP 12 0K 2K 166960K 40 0 temp 40 9103K 9119K 166960K 22964 0 kqueue 4 8K 26K 166960K 69 0 SYN cache 2 16K 16K 166960K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 49 0 49 1 0 1 1 0 8 1 rtentry 136 127 0 46 4 0 4 4 0 8 0 unpcb 144 213 0 211 4 0 4 4 0 8 3 syncache 336 5 0 5 1 0 1 1 0 8 1 tcpcb 736 132 0 130 4 0 4 4 0 8 3 arp 96 20 0 8 1 0 1 1 0 8 0 ipq 40 2 0 0 1 0 1 1 0 8 0 ipqe 40 2 0 0 1 0 1 1 0 8 0 inpcb 328 404 0 400 7 0 7 7 0 8 6 nd6 112 29 0 7 1 0 1 1 0 8 0 pkpcb 40 3 0 3 1 0 1 1 0 8 1 kcovpl 48 9 0 1 1 0 1 1 0 8 0 ppxss 1072 13 0 12 1 0 1 1 0 8 0 pppxif 1416 2 0 2 1 0 1 1 0 8 1 pfstscr 40 134 0 131 1 0 1 1 0 8 0 pfrktable 1344 3 0 3 1 0 1 1 0 8 1 pfanchor 1288 6 0 2 1 0 1 1 0 8 0 pfstitem 24 5 0 0 1 0 1 1 0 8 0 pfstkey 128 136 0 131 1 0 1 1 0 8 0 pfstate 384 69 0 66 1 0 1 1 0 8 0 pfrule 1360 1 0 1 1 0 1 1 0 8 1 rttmr 136 1 0 1 1 0 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 543 0 178 29 0 29 29 0 8 4 art_table 40 544 0 178 5 0 5 5 0 8 0 art_node 32 127 0 55 1 0 1 1 0 8 0 sysvmsgpl 40 4 0 2 1 0 1 1 0 8 0 semapl 72 9 0 2 1 0 1 1 0 8 0 shmpl 112 8 0 1 1 0 1 1 0 8 0 dirhash 1024 23 0 6 3 0 3 3 0 8 0 dino2pl 256 2045 0 591 92 0 92 92 0 8 0 ffsino 256 2045 0 591 92 0 92 92 0 8 0 nchpl 144 2556 0 858 64 0 64 64 0 8 0 rtmask 32 3 0 2 1 0 1 1 0 8 0 vnodes 216 2322 0 0 129 0 129 129 0 8 0 namei 1024 8393 0 8393 2 0 2 2 0 8 2 pfiaddrpl 120 1 0 1 1 0 1 1 0 8 1 kstatmem 264 45 0 20 3 0 3 3 0 8 1 scsiplug 72 2 0 2 1 0 1 1 0 8 1 scxspl 216 8678 0 8678 8 0 8 8 1 8 8 plimitpl 152 119 0 109 1 0 1 1 0 8 0 sigapl 424 688 0 638 8 0 8 8 0 8 0 knotepl 120 11338 0 11316 15 0 15 15 0 8 11 kqueuepl 184 154 0 150 4 0 4 4 0 8 2 pipepl 304 204 0 176 8 0 8 8 0 8 5 fdescpl 448 655 0 638 5 0 5 5 0 8 1 filepl 120 3436 0 3271 14 0 14 14 0 8 6 lockfpl 104 85 0 83 1 0 1 1 0 8 0 lockfspl 48 39 0 37 1 0 1 1 0 8 0 sessionpl 144 36 0 34 1 0 1 1 0 8 0 pgrppl 48 50 0 40 1 0 1 1 0 8 0 ucredpl 104 406 0 403 1 0 1 1 0 8 0 zombiepl 144 639 0 638 1 0 1 1 0 8 0 processpl 1152 688 0 638 5 0 5 5 0 8 0 procpl 664 1029 0 974 7 0 7 7 0 8 1 sosppl 176 1 0 1 1 0 1 1 0 8 1 sockpl 552 678 0 672 7 0 7 7 0 8 6 mcl64k 65536 15 0 15 1 0 1 1 0 8 1 mcl16k 16384 2 0 2 1 0 1 1 0 8 1 mcl9k128 9344 2 0 2 1 0 1 1 0 8 1 mcl8k 8192 8 0 8 1 0 1 1 0 8 1 mcl4k 4096 2801 0 2742 13 0 13 13 0 8 5 mcl2k 2048 345 0 344 2 0 2 2 0 8 1 mtagpl 96 4 0 3 1 0 1 1 0 8 0 mbufpl 256 6865 0 6731 16 0 16 16 0 8 5 bufpl 272 4010 0 102 261 0 261 261 0 8 0 anonpl 24 111413 0 110000 43 0 43 43 0 186 21 amapchunkpl 152 15172 0 14872 26 0 26 26 0 158 10 amappl16 200 1842 0 1822 14 4 10 14 0 8 8 amappl15 192 10 0 10 1 0 1 1 0 8 1 amappl14 184 414 0 414 1 0 1 1 0 8 1 amappl13 176 156 0 155 1 0 1 1 0 8 0 amappl12 168 892 0 876 2 0 2 2 0 8 0 amappl11 160 7 0 6 1 0 1 1 0 8 0 amappl10 152 56 0 56 1 0 1 1 0 8 1 amappl9 144 308 0 308 1 0 1 1 0 8 1 amappl8 136 122 0 122 1 0 1 1 0 8 1 amappl7 128 138 0 136 1 0 1 1 0 8 0 amappl6 120 164 0 163 1 0 1 1 0 8 0 amappl5 112 90 0 89 1 0 1 1 0 8 0 amappl4 104 282 0 278 1 0 1 1 0 8 0 amappl3 96 2919 0 2851 3 0 3 3 0 8 0 amappl2 88 528 0 519 2 0 2 2 0 8 0 amappl1 80 11193 0 11083 13 0 13 13 0 8 7 amappl 88 4138 0 4036 4 0 4 4 0 92 0 uvmvnodes 80 103 0 0 3 0 3 3 0 8 0 dma4096 4096 1 0 1 1 0 1 1 0 8 1 dma1024 1024 1 0 0 1 0 1 1 0 8 0 dma256 256 7 0 7 1 0 1 1 0 8 1 dma128 128 253 0 253 1 0 1 1 0 8 1 dma64 64 6 0 6 1 0 1 1 0 8 1 dma32 32 7 0 7 1 0 1 1 0 8 1 dma16 16 18 0 17 1 0 1 1 0 8 0 aobjpl 72 10 0 1 1 0 1 1 0 8 0 uaddrrnd 24 655 0 638 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 655 0 638 1 0 1 1 0 8 0 vmmpekpl 168 7225 0 7189 2 0 2 2 0 8 0 vmmpepl 168 49756 0 49021 87 0 87 87 0 357 46 vmsppl 368 654 0 638 4 0 4 4 0 8 1 rwobjpl 40 16498 0 16089 12 0 12 12 0 8 1 pdppl 4096 1316 0 1276 98 52 46 78 0 8 6 pvpl 32 297056 0 292441 109 0 109 109 0 265 53 pmappl 216 654 0 638 2 0 2 2 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 630 0 52 17 0 17 17 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83482c9a) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff834c213b,ffffffff8341da6c,1cb,ffffffff8347f631) at __assert+0x29 sys/kern/subr_prf.c:-1 pipex_unlink_session_locked(ffff80003c8ebaa0) at pipex_unlink_session_locked+0x429 pipex_destroy_all_sessions(ffff800001587800) at pipex_destroy_all_sessions+0xd9 pipex_rele_session sys/net/pipex.c:-1 [inline] pipex_destroy_all_sessions(ffff800001587800) at pipex_destroy_all_sessions+0xd9 sys/net/pipex.c:151 pppacclose(6381,1,2000,ffff80003a4dd4e0) at pppacclose+0x16f sys/net/if_pppx.c:1335 spec_close(ffff80002a75cec0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(ffffef806f6ac7e0,1,ffffef8007ffd618,ffff80003a4dd4e0) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(ffffef80697495a0,ffff80003a4dd4e0) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(ffffef80697495a0,ffff80003a4dd4e0) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621 fdrop(ffffef80697495a0,ffff80003a4dd4e0) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(ffffef80697495a0,ffff80003a4dd4e0) at closef+0x190 sys/kern/kern_descrip.c:1265 fdfree(ffff80003a4dd4e0) at fdfree+0x115 sys/kern/kern_descrip.c:1196 exit1(ffff80003a4dd4e0,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003a4dd4e0,ffff80002a75d220,ffff80002a75d170) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80002a75d220) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80002a75d220) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7acb9a60f380, count: -16 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83482c9a) at panic+0x1cf sys/kern/subr_prf.c:198 __assert(ffffffff834c213b,ffffffff8341da6c,1cb,ffffffff8347f631) at __assert+0x29 sys/kern/subr_prf.c:-1 pipex_unlink_session_locked(ffff80003c8ebaa0) at pipex_unlink_session_locked+0x429 pipex_destroy_all_sessions(ffff800001587800) at pipex_destroy_all_sessions+0xd9 pipex_rele_session sys/net/pipex.c:-1 [inline] pipex_destroy_all_sessions(ffff800001587800) at pipex_destroy_all_sessions+0xd9 sys/net/pipex.c:151 pppacclose(6381,1,2000,ffff80003a4dd4e0) at pppacclose+0x16f sys/net/if_pppx.c:1335 spec_close(ffff80002a75cec0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(ffffef806f6ac7e0,1,ffffef8007ffd618,ffff80003a4dd4e0) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(ffffef80697495a0,ffff80003a4dd4e0) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline] vn_closefile(ffffef80697495a0,ffff80003a4dd4e0) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621 fdrop(ffffef80697495a0,ffff80003a4dd4e0) at fdrop+0x121 sys/kern/kern_descrip.c:1281 closef(ffffef80697495a0,ffff80003a4dd4e0) at closef+0x190 sys/kern/kern_descrip.c:1265 fdfree(ffff80003a4dd4e0) at fdfree+0x115 sys/kern/kern_descrip.c:1196 exit1(ffff80003a4dd4e0,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003a4dd4e0,ffff80002a75d220,ffff80002a75d170) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80002a75d220) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80002a75d220) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7acb9a60f380, count: -16 ddb>