The build was failing with duplicate symbol errors with -fno-common.
This is the default in GCC 10 and later, and explicitly enabled in some
distributions to catch problems like this. There were two causes:
- Prog and shadow_logfd were defined in a header file that was included
in multiple other files. Fix this by defining them once in
shadowlog.c, and having extern declarations in the header.
- Most of the tools (except id/nologin) also define a Prog variable,
which is not intended to alias the one in the library. Fix
this by renaming Prog in the library to shadow_progname, which also
matches the new accessor functions for it.
We were overriding this when --enable-shared was passed. We can actually
just dump the conditional logic as libtool will do the right thing for
us here anyway.
Without this patch, libsubid is installed as .0.
Signed-off-by: Sam James <sam@gentoo.org>
The SIGCHLD handler could have been ignored by parent process.
Make sure that we have default handling activated.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
That special case is already handled by the called function: strtoday()
so we can simplify the calling code.
Link: <https://github.com/shadow-maint/shadow/issues/454>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
This conforms to PAM documentation and it is needed to support
ambient capabilities with PAM + libcap-2.58+.
Signed-off-by: Björn Fischer <bf@CeBiTec.Uni-Bielefeld.DE>
Rename libsubid symbols to all be prefixed with subid_.
Don't export anything but the subid_*.
Closes#443
Signed-off-by: Serge Hallyn <serge@hallyn.com>
* Change to markdown format
* Include an introduction
* Remove the commit mailing list from the contacts
* Add the IRC channel to the contacts
* Move 'S/Key' section to doc/README.skey
* Move authors and maintainers to AUTHORS.md
Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
Add an additional NULL check condition in spw_free() and pw_free() to
avoid freeing an already empty pointer.
Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
Rename list_subid_ranges to getsubids to provide a system binary to
check the sub*ids of a user. The intention is to provide this binary
with any distribution that includes the subid feature, so that system
administrators can check the subid ranges of a given user.
Finally, add a man page to explain the behaviour of getsubids.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1980780
Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
As shadow_logfd variable is not set at the beginning of the program if
something fails and fprintf() is called a segmentation fault happens.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2021339
Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>
Always set SIGCHLD handler to default, even if the caller of vipw has
set SIGCHLD to ignore. If SIGCHLD is ignored no zombie processes would
be created, which in turn could mean that kill is called with an already
recycled pid.
Proof of Concept:
1. Compile nochld:
--
#include <signal.h>
#include <unistd.h>
int main(void) {
char *argv[] = { "vipw", NULL };
signal(SIGCHLD, SIG_IGN);
execvp("vipw", argv);
return 1;
}
--
2. Run nochld
3. Suspend child vi, which suspends vipw too:
`kill -STOP childpid`
4. Kill vi:
`kill -9 childpid`
5. You can see with ps that childpid is no zombie but disappeared
6. Bring vipw back into foreground
`fg`
The kill call sends SIGCONT to "childpid" which in turn could have been
already recycled for another process.
This is definitely not a vulnerability. It would take super user
operations, at which point an attacker would have already elevated
permissions.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
