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path: root/util-linux/setpriv.c
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2017-07-07setpriv: remove dependency on libcap headersDenys Vlasenko
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-07-07setpriv: factor out capability name printingDenys Vlasenko
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-07-07setpriv: code shrink, and grouping capability code togetherDenys Vlasenko
function old new delta static.versions - 3 +3 getcaps 174 149 -25 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-07-07setpriv: allow modifying ambient capabilitiesPatrick Steinhardt
With Linux 4.3, a new set of capabilities has been introduced with the ambient capabilities. These aim to solve the problem that it was impossible to grant run programs with elevated privileges across non-root users. Quoting from capabilities(7): This is a set of capabilities that are preserved across an execve(2) of a program that is not privileged. The ambient capability set obeys the invariant that no capability can ever be ambient if it is not both permitted and inheritable. With this new set of capabilities it is now possible to run an executable with elevated privileges as a different user, making it much easier to do proper privilege separation. Note though that the `--ambient-caps` switch is not part of any released version of util-linux, yet. It has been applied in 0c92194ee (setpriv: support modifying the set of ambient capabilities, 2017-06-24) and will probably be part of v2.31. function old new delta parse_cap - 174 +174 setpriv_main 1246 1301 +55 .rodata 146307 146347 +40 static.setpriv_longopts 40 55 +15 packed_usage 32092 32079 -13 Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-07-07setpriv: allow modifying inheritable capsPatrick Steinhardt
The main use case of setpriv is to modify the current state of privileges available to the calling process and spawn a new executable with the modified, new state. Next to the already supported case of modifying the no-new-privs flag, util-linux also supports to modify capability sets. This commit introduces to add or drop capabilities from the set of inheritable capabilities. Quoting from capabilities(7): This is a set of capabilities preserved across an execve(2). Inheritable capabilities remain inheritable when executing any program, and inheritable capabilities are added to the permitted set when executing a program that has the corresponding bits set in the file inheritable set. As such, inheritable capabilities enable executing files with certain privileges if the file itself has these privileges set. Note though that inheritable capabilities are dropped across execve when running as a non-root user. function old new delta getcaps - 237 +237 setpriv_main 1129 1246 +117 .rodata 146198 146307 +109 static.setpriv_longopts 29 40 +11 packed_usage 32107 32092 -15 Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-07-06setpriv: dump ambient capabilitiesPatrick Steinhardt
As with the previous commit, this commit introduces the ability to dump the set of ambient capabilities. function old new delta setpriv_main 982 1129 +147 .rodata 146148 146198 +50 Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-07-06setpriv: dump capability bounding setPatrick Steinhardt
As with the previous commit, this one implements the ability to dump the capability bounding set. function old new delta setpriv_main 838 982 +144 .rodata 146101 146148 +47 Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-07-06setpriv: dump inheritable capability setPatrick Steinhardt
The setpriv executable from util-linux also dumps out information on the different capability sets known by the kernel. By default, these are the inheritable capabilities, bounding capabilities and (not yet released) the ambient capabilities, which have been introduced with Linux 4.3. This patch introduces the ability to dump the set of inheritable capabilities. By default, setpriv(1) identifies capabilities by their human-readable name, for example 'net_admin'. For unknown capabilities, though, it does instead use the capability's value, for example 'cap_12', which is equivalent to 'net_admin'. As there is no kernel interface to retrieve capability names by their index, we have to declare these ourselves, which adds to setpriv's size. To counteract, using the human-readble name has been made configurable. The following sizes are with the 'FEATURE_SETPRIV_CAPABILITY_NAMES' enabled: function old new delta .rodata 145969 146405 +436 setpriv_main 467 842 +375 capabilities - 304 +304 And with 'FEATURE_SETPRIV_CAPABILITY_NAMES' disabled: function old new delta setpriv_main 467 838 +371 .rodata 145969 146101 +132 Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-07-06setpriv: dump no-new-privs infoPatrick Steinhardt
Introduce the ability to dump the state of the no-new-privs flag, which states whethere it is allowed to grant new privileges. function old new delta setpriv_main 419 467 +48 .rodata 145926 145969 +43 Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-07-04setpriv: dump user and group infoDenys Vlasenko
setpriv from util-linux has an option to dump the current state regarding privilege settings via '--dump'. It prints out information on the real and effective user and group IDs, supplementary groups, the no-new-privs flag, the capability sets as well as secure bits. This patch is the start of supporting this mode. To make introduction of the '--dump' easier to reason about, its introduction has been split into multiple patches. This particular one introduces the ability to print out user and group information of the current process. function old new delta setpriv_main 89 322 +233 getresuid - 41 +41 getresgid - 41 +41 static.setpriv_longopts 22 29 +7 packed_usage 31675 31669 -6 ------------------------------------------------------------------------------ (add/remove: 4/0 grow/shrink: 2/1 up/down: 322/-6) Total: 316 bytes Patch by Patrick Steinhardt <ps@pks.im> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-07-04setpriv: prepare option parsing logic for additional optsPatrick Steinhardt
The current option parsing logic of setpriv only supports the case where we want to execute a sub-program and have at most one argument. Refactor handling of options to solve these shortcomings to make it easy to support 'setpriv --dump', which does not accept any additional arguments, as well as the case where additional options are passed to setpriv. This is done by handling 'argc' ourselves, throwing an error when no program is specified, as well as introducing an enum for the different option bitmasks. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-07-04setpriv: do not process remaining argsPatrick Steinhardt
By default, the 'getopt32' call will continue parsing the command line even after hitting a non-option string. But in setpriv, this should be avoided, as all parameters following the initial non-option argument are in fact arguments to the binary that is to be executed by setpriv. Otherwise, calling e.g. 'busybox setpriv ls -l' would result in an error due to the unknown parameter "-l". Fix the issue by passing "+" as the first character in the options string. This will cause 'getopt32' to stop processing after hitting the first non-option. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-06-14setpriv: new appletAssaf Gordon
Add a minimal 'setpriv' implementation supporting the NO_NEW_PRIVS bit. Typical usage: $ busybox setpriv sudo uname Linux $ busybox setpriv --nnp sudo uname sudo: effective uid is not 0, is /usr/bin/sudo on a file system with the 'nosuid' option set or an NFS file system without root privileges? function old new delta packed_usage 31580 31685 +105 setpriv_main - 87 +87 prctl - 53 +53 static.setpriv_longopts - 22 +22 applet_names 2620 2628 +8 applet_main 1516 1520 +4 ------------------------------------------------------------------------------ (add/remove: 5/0 grow/shrink: 3/0 up/down: 279/0) Total: 279 bytes Signed-off-by: Assaf Gordon <assafgordon@gmail.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>