getpass(3) is broken in all implementations; in some, more than
others, but somewhat broken in all of them. Check the immediate
previous commit, which added the functions, for more details.
Check also the Linux man-pages commit that marked it as
deprecated, for more details:
7ca189099d73bde954eed2d7fc21732bcc8ddc6b.
Link: <https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit?id=7ca189099d73bde954eed2d7fc21732bcc8ddc6b>
Reported-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
PARAMETERS:
According to the C2x charter, I reordered the parameters 'size'
and 'buf' from previously existing date_to_str() definitions.
C2x charter:
> 15. Application Programming Interfaces (APIs) should be
> self-documenting when possible. In particular, the order of
> parameters in function declarations should be arranged such that
> the size of an array appears before the array. The purpose is to
> allow Variable-Length Array (VLA) notation to be used. This not
> only makes the code's purpose clearer to human readers, but also
> makes static analysis easier. Any new APIs added to the Standard
> should take this into consideration.
I used 'long' for the date parameter, as some uses of the function
need to pass a negative value meaning "never".
FUNCTION BODY:
I didn't check '#ifdef HAVE_STRFTIME', which old definitions did,
since strftime(3) is guaranteed by the C89 standard, and all of
the conversion specifiers that we use are also specified by that
standard, so we don't need any extensions at all.
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
When the -S and -a options are used for passwd to list the status
of all passwords, there is a chance the pw_passwd field of struct
passwd will be NULL. This can be due to 'files compat' being set
for passwd in /etc/nsswitch.conf and the usage of some features
not available in the 'files' mode (e.g. a plus sign at the start
of a line).
Example:
germ161:~ # grep passwd /etc/nsswitch.conf
passwd: files compat
germ161:~ # rpm -qa shadow
shadow-4.2.1-34.20.x86_64
germ161:~ # grep passwd /etc/nsswitch.conf
passwd: files compat
germ161:~ # grep + /etc/passwd
+@nisgroup
germ161:~ # passwd -S -a > /dev/null
Segmentation fault (core dumped)
With this commit:
germ161:~ # passwd -S -a > /dev/null
passwd: malformed password data obtained for user +@nisgroup
Error: RESOURCE_LEAK (CWE-772): [#def1]
shadow-4.8.1/lib/commonio.c:320: alloc_fn: Storage is returned from allocation function "fopen_set_perms".
shadow-4.8.1/lib/commonio.c:320: var_assign: Assigning: "bkfp" = storage returned from "fopen_set_perms(backup, "w", &sb)".
shadow-4.8.1/lib/commonio.c:329: noescape: Resource "bkfp" is not freed or pointed-to in "putc".
shadow-4.8.1/lib/commonio.c:334: noescape: Resource "bkfp" is not freed or pointed-to in "fflush".
shadow-4.8.1/lib/commonio.c:339: noescape: Resource "bkfp" is not freed or pointed-to in "fileno".
shadow-4.8.1/lib/commonio.c:342: leaked_storage: Variable "bkfp" going out of scope leaks the storage it points to.
340| || (fclose (bkfp) != 0)) {
341| /* FIXME: unlink the backup file? */
342|-> return -1;
343| }
344|
Error: RESOURCE_LEAK (CWE-772): [#def2]
shadow-4.8.1/libmisc/addgrps.c:69: alloc_fn: Storage is returned from allocation function "malloc".
shadow-4.8.1/libmisc/addgrps.c:69: var_assign: Assigning: "grouplist" = storage returned from "malloc(i * 4UL)".
shadow-4.8.1/libmisc/addgrps.c:73: noescape: Resource "grouplist" is not freed or pointed-to in "getgroups". [Note: The source code implementation of the function has been overridden by a builtin model.]
shadow-4.8.1/libmisc/addgrps.c:126: leaked_storage: Variable "grouplist" going out of scope leaks the storage it points to.
124| }
125|
126|-> return 0;
127| }
128| #else /* HAVE_SETGROUPS && !USE_PAM */
Error: RESOURCE_LEAK (CWE-772): [#def3]
shadow-4.8.1/libmisc/chowntty.c:62: alloc_fn: Storage is returned from allocation function "getgr_nam_gid".
shadow-4.8.1/libmisc/chowntty.c:62: var_assign: Assigning: "grent" = storage returned from "getgr_nam_gid(getdef_str("TTYGROUP"))".
shadow-4.8.1/libmisc/chowntty.c:98: leaked_storage: Variable "grent" going out of scope leaks the storage it points to.
96| */
97| #endif
98|-> }
99|
Error: RESOURCE_LEAK (CWE-772): [#def4]
shadow-4.8.1/libmisc/copydir.c:742: 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/libmisc/copydir.c:742: var_assign: Assigning: "ifd" = handle returned from "open(src, 0)".
shadow-4.8.1/libmisc/copydir.c:748: leaked_handle: Handle variable "ifd" going out of scope leaks the handle.
746| #ifdef WITH_SELINUX
747| if (set_selinux_file_context (dst, NULL) != 0) {
748|-> return -1;
749| }
750| #endif /* WITH_SELINUX */
Error: RESOURCE_LEAK (CWE-772): [#def5]
shadow-4.8.1/libmisc/copydir.c:751: 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/libmisc/copydir.c:751: var_assign: Assigning: "ofd" = handle returned from "open(dst, 577, statp->st_mode & 0xfffU)".
shadow-4.8.1/libmisc/copydir.c:752: noescape: Resource "ofd" is not freed or pointed-to in "fchown_if_needed".
shadow-4.8.1/libmisc/copydir.c:775: leaked_handle: Handle variable "ofd" going out of scope leaks the handle.
773| ) {
774| (void) close (ifd);
775|-> return -1;
776| }
777|
Error: RESOURCE_LEAK (CWE-772): [#def7]
shadow-4.8.1/libmisc/idmapping.c:188: alloc_fn: Storage is returned from allocation function "xmalloc".
shadow-4.8.1/libmisc/idmapping.c:188: var_assign: Assigning: "buf" = storage returned from "xmalloc(bufsize)".
shadow-4.8.1/libmisc/idmapping.c:188: var_assign: Assigning: "pos" = "buf".
shadow-4.8.1/libmisc/idmapping.c:213: noescape: Resource "buf" is not freed or pointed-to in "write".
shadow-4.8.1/libmisc/idmapping.c:219: leaked_storage: Variable "pos" going out of scope leaks the storage it points to.
shadow-4.8.1/libmisc/idmapping.c:219: leaked_storage: Variable "buf" going out of scope leaks the storage it points to.
217| }
218| close(fd);
219|-> }
Error: RESOURCE_LEAK (CWE-772): [#def8]
shadow-4.8.1/libmisc/list.c:211: alloc_fn: Storage is returned from allocation function "xstrdup".
shadow-4.8.1/libmisc/list.c:211: var_assign: Assigning: "members" = storage returned from "xstrdup(comma)".
shadow-4.8.1/libmisc/list.c:217: var_assign: Assigning: "cp" = "members".
shadow-4.8.1/libmisc/list.c:218: noescape: Resource "cp" is not freed or pointed-to in "strchr".
shadow-4.8.1/libmisc/list.c:244: leaked_storage: Variable "cp" going out of scope leaks the storage it points to.
shadow-4.8.1/libmisc/list.c:244: leaked_storage: Variable "members" going out of scope leaks the storage it points to.
242| if ('\0' == *members) {
243| *array = (char *) 0;
244|-> return array;
245| }
246|
Error: RESOURCE_LEAK (CWE-772): [#def11]
shadow-4.8.1/libmisc/myname.c:61: alloc_fn: Storage is returned from allocation function "xgetpwnam".
shadow-4.8.1/libmisc/myname.c:61: var_assign: Assigning: "pw" = storage returned from "xgetpwnam(cp)".
shadow-4.8.1/libmisc/myname.c:67: leaked_storage: Variable "pw" going out of scope leaks the storage it points to.
65| }
66|
67|-> return xgetpwuid (ruid);
68| }
69|
Error: RESOURCE_LEAK (CWE-772): [#def12]
shadow-4.8.1/libmisc/user_busy.c:260: alloc_fn: Storage is returned from allocation function "opendir".
shadow-4.8.1/libmisc/user_busy.c:260: var_assign: Assigning: "task_dir" = storage returned from "opendir(task_path)".
shadow-4.8.1/libmisc/user_busy.c:262: noescape: Resource "task_dir" is not freed or pointed-to in "readdir".
shadow-4.8.1/libmisc/user_busy.c:278: leaked_storage: Variable "task_dir" going out of scope leaks the storage it points to.
276| _("%s: user %s is currently used by process %d\n"),
277| Prog, name, pid);
278|-> return 1;
279| }
280| }
Error: RESOURCE_LEAK (CWE-772): [#def20]
shadow-4.8.1/src/newgrp.c:162: alloc_fn: Storage is returned from allocation function "xgetspnam".
shadow-4.8.1/src/newgrp.c:162: var_assign: Assigning: "spwd" = storage returned from "xgetspnam(pwd->pw_name)".
shadow-4.8.1/src/newgrp.c:234: leaked_storage: Variable "spwd" going out of scope leaks the storage it points to.
232| }
233|
234|-> return;
235|
236| failure:
Error: RESOURCE_LEAK (CWE-772): [#def21]
shadow-4.8.1/src/passwd.c:530: alloc_fn: Storage is returned from allocation function "xstrdup".
shadow-4.8.1/src/passwd.c:530: var_assign: Assigning: "cp" = storage returned from "xstrdup(crypt_passwd)".
shadow-4.8.1/src/passwd.c:551: noescape: Resource "cp" is not freed or pointed-to in "strlen".
shadow-4.8.1/src/passwd.c:554: noescape: Resource "cp" is not freed or pointed-to in "strcat". [Note: The source code implementation of the function has been overridden by a builtin model.]
shadow-4.8.1/src/passwd.c:555: overwrite_var: Overwriting "cp" in "cp = newpw" leaks the storage that "cp" points to.
553| strcpy (newpw, "!");
554| strcat (newpw, cp);
555|-> cp = newpw;
556| }
557| return cp;
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().
Signed-off-by: Serge Hallyn <serge@hallyn.com>
Using hard-coded access vector ids is deprecated and can lead to issues with custom SELinux policies.
Switch to `selinux_check_access()`.
Also use the libselinux log callback and log if available to audit.
This makes it easier for users to catch SELinux denials.
Drop legacy shortcut logic for passwd, which avoided a SELinux check if uid 0 changes a password of a user which username equals the current SELinux user identifier.
Nowadays usernames rarely match SELinux user identifiers and the benefit of skipping a SELinux check is negligible.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Some distributions, notably Fedora, have the following order of nsswitch
modules by default:
passwd: sss files
group: sss files
The advantage of serving local users through SSSD is that the nss_sss
module has a fast mmapped-cache that speeds up NSS lookups compared to
accessing the disk an opening the files on each NSS request.
Traditionally, this has been done with the help of nscd, but using nscd
in parallel with sssd is cumbersome, as both SSSD and nscd use their own
independent caching, so using nscd in setups where sssd is also serving
users from some remote domain (LDAP, AD, ...) can result in a bit of
unpredictability.
More details about why Fedora chose to use sss before files can be found
on e.g.:
https://fedoraproject.org//wiki/Changes/SSSDCacheForLocalUsers
or:
https://docs.pagure.org/SSSD.sssd/design_pages/files_provider.html
Now, even though sssd watches the passwd and group files with the help
of inotify, there can still be a small window where someone requests a
user or a group, finds that it doesn't exist, adds the entry and checks
again. Without some support in shadow-utils that would explicitly drop
the sssd caches, the inotify watch can fire a little late, so a
combination of commands like this:
getent passwd user || useradd user; getent passwd user
can result in the second getent passwd not finding the newly added user
as the racy behaviour might still return the cached negative hit from
the first getent passwd.
This patch more or less copies the already existing support that
shadow-utils had for dropping nscd caches, except using the "sss_cache"
tool that sssd ships.
The third field in the /etc/shadow file (sp_lstchg) contains the date of
the last password change expressed as the number of days since Jan 1, 1970.
As this is a relative time, creating a user today will result in:
username:17238:0:99999:7:::
whilst creating the same user tomorrow will result in:
username:17239:0:99999:7:::
This has an impact for the Reproducible Builds[0] project where we aim to
be independent of as many elements the build environment as possible,
including the current date.
This patch changes the behaviour to use the SOURCE_DATE_EPOCH[1]
environment variable (instead of Jan 1, 1970) if valid.
[0] https://reproducible-builds.org/
[1] https://reproducible-builds.org/specs/source-date-epoch/
Signed-off-by: Chris Lamb <lamby@debian.org>
passwd, shadow, group, gshadow etc. can be managed via nss -
e.g. system default accounts can be specified using nss_altfiles,
rather than in /etc/. Thus despite having default accounts, these
files can be missing on disk and thus should be opened with O_CREATE
whenever they are attempted to be opened in O_RDWR modes.
* Changelog: Update documentation of 2013-07-28 mancha entry.
* lib/prototypes.h, lib/encrypt.c: Update splint marker,
pw_encrypt can return NULL.
* lib/encrypt.c: Fix outdated statement on GNU crypt.
* src/chgpasswd.c: Improve diagnostic to user when pw_encrypt
fails and use fail_exit() instead of exit().
* src/chpasswd.c: Likewise.
* src/newusers.c: Likewise.
* src/passwd.c: Likewise when new password is encrypted.
* src/newgrp.c: Improve diagnostic to user and syslog when
pw_encrypt fails. Do not apply 1s penalty as this is not an
invalid password issue.
* src/passwd.c: Likewise when password is checked.
a salt that violates specs. On Linux, crypt() also fails with
DES/MD5 salts in FIPS140 mode. Rather than exit() on NULL returns
we send them back to the caller for appropriate handling.
* lib/commonio.c: Avoid multiple statements per line.
* lib/commonio.c: Ignore fclose return value when the file was
open read only or was not changed, or if an error is already
reported.
instead of an int.
* libmisc/obscure.c, libmisc/tz.c, src/passwd.c, lib/encrypt.c,
libmisc/copydir.c, lib/prototypes.h: Add splint annotations.
* libmisc/tz.c: Fix some const issues.
* libmisc/tz.c: Avoid multi-statements lines.
* libmisc/tz.c: Add brackets.
* libmisc/copydir.c: Do not check *printf/*puts return value.
* libmisc/copydir.c: Fail if we cannot set or reset the SELinux
fscreate context.
* libmisc/copydir.c: Use xmalloc instead of malloc.
* libmisc/copydir.c: Do not check lutimes return value
* src/vipw.c: Avoid implicit conversion of integer to boolean.
* src/su.c (iswheel): Return a bool instead of an int.
* src/passwd.c: Remove insert_crypt_passwd(). Use xstrdup instead.
* src/passwd.c: Return constant strings when sufficient.
* src/passwd.c: Do not check *printf/*puts return value.
* src/passwd.c: Avoid implicit conversion of character to boolean.
* src/passwd.c: Do not check sleep return value.
* src/sulogin.c: Do not check *printf/*puts return value.
* lib/encrypt.c: Do not check fprintf return value.
* src/login_nopam.c: Limit the scope of variables end, lineno, i,
str_len.
* src/logoutd.c: Limit the scope of variable c.
* src/vipw.c: Re-indent.
* src/vipw.c: Close the file after the creation of the backup.
* src/useradd.c (set_default): Close input file on failure.
* src/useradd.c: Limit the scope of variables spool, file, fd, gr,
gid, mode.
* src/passwd.c: Limit the scope of variables last and ok.
* src/chage.c: Fix typo (non breaking space).
* src/login.c: Limit the scope of variables erasechar killchar, c,
failed.
* src/groups.c: Limit the scope of variable ngroups, pri_grp, i.
* src/id.c: Limit the scope of variable i.
src/chpasswd.c, src/groupmems.c, src/usermod.c, src/chgpasswd.c,
src/vipw.c, src/su.c, src/useradd.c, src/groupmod.c, src/passwd.c,
src/groupadd.c, src/chage.c, src/faillog.c, src/chsh.c: Use
booleans for tests.
* src/userdel.c, src/gpasswd.c, src/groupmems.c, src/usermod.c,
src/groupmod.c, src/passwd.c: Use a break even after usage().
src/newusers.c, src/chpasswd.c, src/groupmems.c, src/usermod.c,
src/chgpasswd.c, src/vipw.c, src/su.c, src/useradd.c,
src/groupmod.c, src/passwd.c, src/groupadd.c, src/chage.c,
src/faillog.c, src/chsh.c: If someone uses the -h/--help options,
the usage should not go to stderr nor should the utility exit with
non-zero status. All of the shadow utils do just this
unfortunately, so convert them over to sanity.
* man/groupmems.8.xml, man/gpasswd.1.xml: Added option -h/--help.
src/passwd.c, src/pwck.c, src/pwconv.c, src/useradd.c,
src/usermod.c: On Jan 01, 1970, do not set the sp_lstchg field to
0 (which means that the password shall be changed during the next
login), but use -1 (password aging disabled).
* src/passwd.c: Do not check sp_min if sp_lstchg is null or -1.
src/newusers.c, src/pwconv.c, src/chpasswd.c, src/logoutd.c,
src/chfn.c, src/groupmems.c, src/usermod.c, src/pwunconv.c,
src/expiry.c, src/groupdel.c, src/chgpasswd.c, src/useradd.c,
src/su.c, src/groupmod.c, src/passwd.c, src/pwck.c,
src/groupadd.c, src/chage.c, src/login.c, src/grpconv.c,
src/groups.c, src/grpunconv.c, src/chsh.c: Prog is now global (not
static to the file) so that it can be used by the helper functions
of libmisc.
* lib/prototypes.h: Added extern char *Prog.
* libmisc/find_new_gid.c, libmisc/find_new_uid.c: Indicate the
program name with the warning.
* src/chage.c, src/chfn.c, src/chgpasswd.c, src/chpasswd.c,
src/chsh.c, src/gpasswd.c, src/groupadd.c, src/groupmems.c,
src/groupmod.c, src/grpck.c, src/grpconv.c, src/grpunconv.c,
src/passwd.c, src/pwck.c, src/pwconv.c, src/pwunconv.c,
src/useradd.c, src/userdel.c, src/usermod.c: Harmonize the error
message sent to stderr in case of *_update () failure.
* src/chage.c, src/chsh.c, src/groupadd.c, src/passwd.c: Do not
log to syslog when pw_update() or spw_update() fail.
* src/newusers.c: Do not log specific error message to stderr when
sgr_update() fails.
* src/pwconv.c: Remove duplicated definition of Prog.
src/newgrp.c, src/passwd.c, src/su.c: Use the same stderr and
syslog warnings when the username cannot be determined.
* src/newgrp.c: Reuse the same stderr message for groups which do
not exist in the system.
