This is a stability fix, not a security fix, because the affected -o
option can only be used by root and it takes a modified passwd file.
If a gecos field for a user has BUFSIZ characters without commas and an
equals sign (i.e. a huge slop/extra field) and chfn is called with -o,
then a buffer overflow occurs.
It is not possible to trigger this with shadow tools. Therefore, the
passwd file must be modified manually.
I have fixed this unlikely case the easiest and cleanest way possible.
Since chfn bails out if more than 80 characters excluding commas are
supposed to be written into gecos field, we can stop processing early on
if -o argument is too long.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
This is merely a stability fix, not a security fix.
As the root user, it is possible to set time values which later on
result in signed integer overflows.
For this to work, an sgetspent implementation must be used which
supports long values (glibc on amd64 only parses 32 bit, not 64).
Either use musl or simply call configure with following environment
variable:
$ ac_cv_func_sgetspent=no ./configure
Also it is recommended to compile with -fsanitize=undefined or
-ftrapv to see these issues easily.
Examples to trigger issues when calling "chage -l user":
$ chage -d 9223372036854775807 user
$ chage -d 106751991167300 user
$ chage -M 9999 user
$ chage -d 90000000000000 user
$ chage -I 90000000000000 user
$ chage -M 9999 user
$ chage -E 9223372036854775807 user
While at it, I fixed casting issues which could lead to signed integer
overflows on systems which still have a 32 bit time_t.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Closes#154
Currently this has three functions: one which returns the
list of subuid ranges for a user, one returning the subgids,
and one which frees the ranges lists.
I might be mistaken about what -disable-man means; some of
the code suggests it means just don't re-generate them, but
not totally ignore them. But that doesn't seem to really work,
so let's just ignore man/ when -disable-man.
Remove --disable-shared. I'm not sure why it was there, but it stems
from long, long ago, and I suspect it comes from some ancient
toolchain bug.
Create a tests/run_some, a shorter version of run_all. I'll
slowly add tests to this as I verify they work, then I can
work on fixing the once which don't.
Also, don't touch man/ if not -enable-man.
Changelog:
Apr 22: change the subid list api as recomended by Dan Walsh.
Apr 23: implement get_subid_owner
Apr 24: implement range add/release
Apr 25: finish tests and rebase
May 10: make @owner const
Signed-off-by: Serge Hallyn <serge@hallyn.com>
Now that travis supports more architectures let's make sure we test on
all of them and that we enable Coverity too.
Signed-off-by: Christian Brauner <christian@brauner.io>
Do not include <sys/prctl.h> we don't have <sys/capability.h>, we don't
need prctl in that case anyway.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
According to crypt(5), MD5 and DES should not be used for new
hashes. Also the default number of SHA rounds chosen by libc is orders
of magnitude too low for modern hardware. Let's warn the users about
weak choices.
Signed-off-by: Topi Miettinen <toiwoton@gmail.com>
