shell升级完整记录
[root@localhost bash-4.3.30]# cat Makefile |grep prefix
prefix = /usr/local
exec_prefix = ${prefix}
datarootdir = ${prefix}/share
bindir = ${exec_prefix}/bin
libdir = ${exec_prefix}/lib
includedir = ${prefix}/include
prefix=${prefix} exec_prefix=${exec_prefix} \
[root@localhost bash-4.3.30]# whereis bash
bash: /usr/bin/bash /usr/local/bin/bash /usr/share/man/man1/bash.1.gz
[root@localhost bash-4.3.30]# /usr/bin/bas
base64 basename bash bashbug bashbug-32
[root@localhost bash-4.3.30]# /usr/bin/bash --version
GNU bash, version 4.2.45(1)-release (i686-redhat-linux-gnu)
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
[root@localhost bash-4.3.30]# /usr/local/bin/bash --version
GNU bash, version 4.3.30(1)-release (i686-pc-linux-gnu)
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
[root@localhost bash-4.3.30]#
库文件查询
[root@localhost bash-4.3.30]# ldd bash
linux-gate.so.1 => (0xb779a000)
libtinfo.so.5 => /lib/libtinfo.so.5 (0x4e41c000)
libdl.so.2 => /lib/libdl.so.2 (0x4c65c000)
libc.so.6 => /lib/libc.so.6 (0x4c49c000)
/lib/ld-linux.so.2 (0x4c473000)
[root@localhost bash-4.3.30]#
[root@localhost shell_up_zhb]# chsh -l
/bin/sh
/bin/bash
/sbin/nologin
/usr/bin/sh
/usr/bin/bash
/usr/sbin/nologin
[root@localhost shell_up_zhb]# lsof /bin/sh
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
bash 8522 root txt REG 253,1 917564 11014242 /usr/bin/bash
[root@localhost shell_up_zhb]# lsof /bin/bash
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
bash 8522 root txt REG 253,1 917564 11014242 /usr/bin/bash
sh 8914 root txt REG 253,1 917564 11014242 /usr/bin/bash
[root@localhost shell_up_zhb]#
1以前的思路是拷贝升级后的可执行文件，库，配置文件（如果有），开始按此思路升级，失败，并且没法登陆。
2 后来发现chsh命令可以设置开机使用的sh，考虑升级登陆后的sh，开机使用另一个，升级成功后在，切换升级另一个。后来发现，系统实际上只用一个sh，次思路不对
3 bash升级只是为了修补心血漏洞，估计只需升级可执行文件即可。通过lsof发现，实际上使用的是/usr/bin/sh的shell，/bin/sh其实是连接，那就只拷贝/usr/bin/sh，/usr/bin/bash,拷贝时发现在使用，那就先复制在拷贝。
4 拷贝成功后，用测试例子试一下，发现可以
[NTP-Fedora20 shell_up_zhb]#env x='() { :;}; echo vulnerable' bash -c "echo this is a test"
vulnerable
this is a test
[NTP-Fedora20 shell_up_zhb]#env x='() { :;}; echo vulnerable' ./bash -c "echo this is a test"
this is a test
5 reboot发现成功
