Iker Pedrosa [Thu, 10 Jun 2021 11:05:03 +0000 (13:05 +0200)]
useradd.c: fix covscan RESOURCE_LEAK
Error: RESOURCE_LEAK (CWE-772): [#def28]
shadow-4.8.1/src/useradd.c:1905: open_fn: Returning handle opened by "open". [Note: The source code implementation of the function has been overridden by a user model.]
shadow-4.8.1/src/useradd.c:1905: var_assign: Assigning: "fd" = handle returned from "open("/var/log/faillog", 2)".
shadow-4.8.1/src/useradd.c:1906: noescape: Resource "fd" is not freed or pointed-to in "lseek".
shadow-4.8.1/src/useradd.c:1917: leaked_handle: Handle variable "fd" going out of scope leaks the handle.
1915| /* continue */
1916| }
1917|-> }
1918|
1919| static void lastlog_reset (uid_t uid)
Error: RESOURCE_LEAK (CWE-772): [#def29]
shadow-4.8.1/src/useradd.c:1938: open_fn: Returning handle opened by "open". [Note: The source code implementation of the function has been overridden by a user model.]
shadow-4.8.1/src/useradd.c:1938: var_assign: Assigning: "fd" = handle returned from "open("/var/log/lastlog", 2)".
shadow-4.8.1/src/useradd.c:1939: noescape: Resource "fd" is not freed or pointed-to in "lseek".
shadow-4.8.1/src/useradd.c:1950: leaked_handle: Handle variable "fd" going out of scope leaks the handle.
1948| /* continue */
1949| }
1950|-> }
1951|
1952| static void tallylog_reset (const char *user_name)
Error: RESOURCE_LEAK (CWE-772): [#def30]
shadow-4.8.1/src/useradd.c:2109: alloc_fn: Storage is returned from allocation function "strdup".
shadow-4.8.1/src/useradd.c:2109: var_assign: Assigning: "bhome" = storage returned from "strdup(prefix_user_home)".
shadow-4.8.1/src/useradd.c:2131: noescape: Resource "bhome" is not freed or pointed-to in "strtok".
shadow-4.8.1/src/useradd.c:2207: leaked_storage: Variable "bhome" going out of scope leaks the storage it points to.
2205| }
2206| #endif
2207|-> }
2208| }
2209|
Iker Pedrosa [Mon, 24 May 2021 10:14:43 +0000 (12:14 +0200)]
man: clarify subid delegation
Clarify that the subid delegation can only come from one source.
Moreover, add an example of what might happen if the subid source is NSS
and useradd is executed.
Serge Hallyn [Sat, 22 May 2021 17:16:50 +0000 (12:16 -0500)]
nss/libsubid: simplify the ranges variable for list_owner_ranges
Following alexey-tikhonov's suggestion.
Since we've dropped the 'owner' field in the data returned for
get_subid_ranges, we can just return a single allocated array of
simple structs. This means we can return a ** instead of ***, and
we can get rid of the subid_free_ranges() helper, since the caller
can just free() the returned data.
Serge Hallyn [Mon, 17 May 2021 02:47:05 +0000 (21:47 -0500)]
Don't return owner in list_owner_ranges API call.
Closes: 339
struct subordinate_range is pretty closely tied to the existing
subid code and /etc/subuid format, so it includes an owner. Dropping
that or even renaming it is more painful than I'd first thought.
So introduce a 'struct subid_range' which is only the start and
count, leaving 'struct subordinate_range' as the owner, start and
count.
Serge Hallyn [Sat, 8 May 2021 22:42:14 +0000 (17:42 -0500)]
libsubid: don't print error messages on stderr by default
Closes #325
Add a new subid_init() function which can be used to specify the
stream on which error messages should be printed. (If you want to
get fancy you can redirect that to memory :) If subid_init() is
not called, use stderr. If NULL is passed, then /dev/null will
be used.
This patch also fixes up the 'Prog', which previously had to be
defined by any program linking against libsubid. Now, by default
in libsubid it will show (subid). Once subid_init() is called,
it will use the first variable passed to subid_init().
When uid 0 maps host uid 0 into the child userns newer kernels require
CAP_SETFCAP be retained as this allows the caller to create fscaps that
are valid in the ancestor userns. This was a security issue (in very
rare circumstances). So whenever host uid 0 is mapped, retain
CAP_SETFCAP if the caller had it.
Userspace won't need to set CAP_SETFCAP on newuidmap as this is really
only a scenario that real root should be doing which always has
CAP_SETFCAP. And if they don't then they are in a locked-down userns.
(LXC sometimes maps host uid 0 during chown operations in a helper
userns but will not rely on newuidmap for that. But we don't want to
risk regressing callers that want to rely on this behavior.)
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Iker Pedrosa [Thu, 6 May 2021 15:23:33 +0000 (17:23 +0200)]
login.defs: include HMAC_CRYPTO_ALGO key
Include the new HMAC_CRYPTO_ALGO key that is needed by pam_timestamp to
select the algorithm that is going to be used to calculate the message
authentication code.
pam_timestamp is currently using an embedded algorithm to calculate the
HMAC message, but the idea is to improve this behaviour by relying on
openssl's implementation. On top of that, the ability to change the
algorithm with a simple configuration change allows to simplify the
process of removing unsecure algorithms.
set_selinux_file_context(): prepare context for actual file type
Search the SELinux selabel database for the file type to be created.
Not specifying the file mode can cause an incorrect file context to be
returned.
Also prepare contexts in commonio_close() for the generic database
filename, not with the backup suffix appended, to ensure the desired
file context after the final rename.
Closes: #322 Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Acked-by: James Carter <jwcart2@gmail.com>
selinux.c: do not use deprecated typedef and skip context translation
These retrieved contexts are just passed to libselinux functions and not
printed or otherwise made available to the outside, so a context
translation to human readable MCS/MLS labels is not needed.
(see man:setrans.conf(5))
vipw[selinux]: do not use deprecated typedef and skip context translation
This retrieved context is just passed to libselinux functions and not
printed or otherwise made available to the outside, so a context
translation to human readable MCS/MLS labels is not needed.
(see man:setrans.conf(5))
Currently, supplying a relative path via the --prefix flag to the
useradd command triggers a bug in the creation of home directories. The
code seems to unintentionally prepend a leading "/" to all paths,
quietly transforming a relative prefixed home path into an absolute
path. This can be seen in the following strace logs from running
"useradd --create-home --prefix tmp/root squat":
```
access("tmp/root//home/squat", F_OK) = -1 ENOENT (No such file or directory)
access("/mp", F_OK) = 0
access("/mp/root", F_OK) = 0
access("/mp/root/home", F_OK) = 0
access("/mp/root/home/squat", F_OK) = -1 ENOENT (No such file or directory)
mkdir("/mp/root/home/squat", 000) = 0
chown("/mp/root/home/squat", 0, 0) = 0
chmod("/mp/root/home/squat", 0755) = 0
chown("tmp/root//home/squat", 1000, 1000) = -1 ENOENT (No such file or directory)
chmod("tmp/root//home/squat", 0700) = -1 ENOENT (No such file or directory)
```
Note that the relative path is correctly probed in the beginning and it
is only during the recursive creation that the path is turned into an
absolute path. This invocation results in the creation of a "/mp"
hierarchy in the root of the filesystem.
Similar problems occur when using `--prefix ./tmp/root`.
This commit fixes the handling of relative paths by not assuming that
the given path is anchored with a "/".
Signed-off-by: Lucas Servén Marín <lserven@gmail.com>
Otherwise our su -p uses bash if that is what root was
configured to use, and then fails to read /root/ for
.bash_profile. This caused an unexpected error message
in /tmp/err, failing the test.
Serge Hallyn [Sun, 31 Jan 2021 23:38:20 +0000 (17:38 -0600)]
subids: support nsswitch
Closes #154
When starting any operation to do with subuid delegation, check
nsswitch for a module to use. If none is specified, then use
the traditional /etc/subuid and /etc/subgid files.
Currently only one module is supported, and there is no fallback
to the files on errors. Several possibilities could be considered:
1. in case of connection error, fall back to files
2. in case of unknown user, also fall back to files
etc...
When non-files nss module is used, functions to edit the range
are not supported. It may make sense to support it, but it also
may make sense to require another tool to be used.
libsubordinateio also uses the nss_ helpers. This is how for instance
lxc could easily be converted to supporting nsswitch.
Add a set of test cases, including a dummy libsubid_zzz module. This
hardcodes values such that:
'ubuntu' gets 200000 - 300000
'user1' gets 100000 - 165536
'error' emulates an nss module error
'unknown' emulates a user unknown to the nss module
'conn' emulates a connection error ot the nss module
Changes to libsubid:
Change the list_owner_ranges api: return a count instead of making the array
null terminated.
This is a breaking change, so bump the libsubid abi major number.
Rename free_subuid_range and free_subgid_range to ungrant_subuid_range,
because otherwise it's confusing with free_subid_ranges which frees
memory.
Serge Hallyn [Mon, 1 Feb 2021 04:44:09 +0000 (22:44 -0600)]
try again to fix libmisc sharing problem
Issue #297 reported seeing
*** Warning: Linking the shared library libsubid.la against the
*** static library ../libmisc/libmisc.a is not portable!
which commit b5fb1b38eea2fb0489ed088c82daf6700e72363e was supposed
to fix. But a few commits later it's back. So try to fix it
in the way the bug reporter suggested. This broke builds some
other ways, namely a few missing library specifications, so add
those.
ikerexxe [Tue, 2 Feb 2021 10:27:17 +0000 (11:27 +0100)]
man: usermod clarification
man/usermod.8.xml: specify what happens when the current home directory
doesn't exist if using -d and -m options. Moreover, specify what happens
when the group ownership is changed and the uid's don't match in -u and
-g options.
ikerexxe [Tue, 2 Feb 2021 10:21:12 +0000 (11:21 +0100)]
man: shadow clarification
man/shadow.5.xml: indicate the exact time and timezone for the dates.
Moreover, clarify that when the password expires the user won't be able
to login.
ikerexxe [Tue, 2 Feb 2021 09:24:32 +0000 (10:24 +0100)]
man: chage clarification
man/chage.1.xml: Indicate that -d option with a value of 0 forces the
user to change his password. Besides, set an example on how to use -E
option. Finally, add a general note to clarify that chage only takes
charge of local users and another note to indicate that it doesn't check
inconsistencies between shadow and passwd files.
ikerexxe [Tue, 27 Oct 2020 10:35:53 +0000 (11:35 +0100)]
useradd: free grp to avoid leak
covscan issue:
Error: RESOURCE_LEAK (CWE-772): [#def39] [important]
src/useradd.c:728: alloc_fn: Storage is returned from allocation function "get_local_group".
src/useradd.c:728: var_assign: Assigning: "grp" = storage returned from "get_local_group(list)".
src/useradd.c:728: overwrite_var: Overwriting "grp" in "grp = get_local_group(list)" leaks the storage that "grp" points to.
726| * GID values, otherwise the string is looked up as is.
727| */
728|-> grp = get_local_group (list);
729|
730| /*
Karel Zak [Thu, 8 Oct 2020 10:17:30 +0000 (12:17 +0200)]
getdefs: add foreign (non-shadow-utils) items
The login.defs is shared between more upstream projects (util-linux,
etc.). We need to improve compatibility between the projects do not
report valid, but foreign items.
Addresses: https://github.com/shadow-maint/shadow/issues/276 Signed-off-by: Karel Zak <kzak@redhat.com>
projects / thirdparty / shadow.git / log
