Commit Graph

11 Commits

Author SHA1 Message Date
Daniel Thompson
a818777d42 libbb: Enable support for !CONFIG_MULTIUSER
Linux recently gained a new config option, CONFIG_MULTIUSER, that makes
support for non-root users optional. This results in a number of syscalls
being disabled: setuid, setregid, setgid, setreuid, setresuid, getresuid,
setresgid, getresgid, setgroups, getgroups, setfsuid, setfsgid, capget,
capset.

Currently a number of busybox applets, including login, struggle to run
when CONFIG_MULTIUSER is disabled. Even the root user is unable to login:
  login: can't set groups: Functi

This patch adds code to make change_identity() a nop on single user
systems. It works by recognising the signature errno value (ENOSYS, due
to the system calls being disabled) and, to avoid security risks, only
deploys when the current uid and target uid is the same.

After the patch is applied any attempt to switch to a non-root user will
fail. Thus a badly configured userspace (for example, one that tries to
start a daemon as a non-root user when the kernel cannot support this)
will report errors as one would expect.

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-05-12 23:59:57 +02:00
Denis Vlasenko
defc1ea340 *: introduce and use FAST_FUNC: regparm on i386, otherwise no-on
text    data     bss     dec     hex filename
 808035     611    6868  815514   c719a busybox_old
 804472     611    6868  811951   c63af busybox_unstripped
2008-06-27 02:52:20 +00:00
Denis Vlasenko
9230582315 inetd: use change_identity().
libbb: shrink our internal initgroups().
httpd: remove stray 'else' and 'index_page = "index.html"'

function                                             old     new   delta
httpd_main                                           750     743      -7
inetd_main                                          2033    2011     -22
bb_internal_initgroups                               251     228     -23
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-52)             Total: -52 bytes
2008-03-20 15:12:58 +00:00
Denis Vlasenko
4e6c8120a5 crond: make it NOMMU-capable
function                                             old     new   delta
safe_setenv4                                           -      62     +62
ForkJob                                              472     511     +39
change_identity                                       21      57     +36
ParseField                                           564     571      +7
SynchronizeDir                                       178     176      -2
LogLevel                                               4       -      -4
LogFile                                                4       -      -4
FileBase                                               4       -      -4
DebugOpt                                               4       -      -4
CDir                                                   4       -      -4
DeleteFile                                           141     132      -9
packed_usage                                       24248   24228     -20
crondlog                                             157     113     -44
change_identity_e2str                                 54       -     -54
SynchronizeFile                                      729     671     -58
crond_main                                          1555    1404    -151
------------------------------------------------------------------------------
(add/remove: 1/6 grow/shrink: 3/6 up/down: 144/-358)         Total: -214 bytes
2008-03-12 22:10:25 +00:00
Denis Vlasenko
0c97c9d437 'simple' error message functions by Loic Grenie <loic.grenie@gmail.com>.
263 bytes saved.
2007-10-01 11:58:38 +00:00
Denis Vlasenko
6ae8079e2d login: re-enable Ctrl-^C before execing shell. 2006-10-31 17:34:44 +00:00
Denis Vlasenko
2e502914b0 login: style fixes 2006-09-08 17:22:45 +00:00
Rob Landley
534374755d Cleaup read() and write() variants, plus a couple of new functions like
xlseek and fdlength() for the new mkswap.
2006-07-16 08:14:35 +00:00
Glenn L McGrath
99bd5adf99 more crond+crontab integrating with loginutil libbb functions and deleted
patch from Thomas Gleixner to init.
Viodz last_patch_108
2003-09-03 12:18:42 +00:00
Manuel Novoa III
cad5364599 Major coreutils update. 2003-03-19 09:13:01 +00:00
Eric Andersen
27f64e1f4e Port over the last of the tinylogin applets
-Erik
2002-06-23 04:24:25 +00:00