The setuid, setgid, and sticky bits are not copied during copy_tree.
Also start with very restrictive permissions before setting ownerships.
This prevents situations in which users in a group with less permissions
than others could win a race in opening the file before permissions are
removed again.
Proof of concept:
$ echo $HOME
/home/uwu
$ install -o uwu -g fandom -m 604 /dev/null /home/uwu/owo
$ ls -l /home/uwu/owo
-rw----r-- 1 uwu fandom 0 Sep 4 00:00 /home/uwu/owo
If /tmp is on another filesystem, then "usermod -md /tmp/uwu uwu" leads
to this temporary situation:
$ ls -l /tmp/uwu/owo
-rw----r-- 1 root root 0 Sep 4 00:00 /tmp/uwu/owo
This means that between openat and chownat_if_needed a user of group
fandom could open /tmp/uwu/owo and read the content when it is finally
written into the file.
Fixes regression introduced in faeab50e71.
If a directory contains fifos, then openat blocks until the other side
of the fifo is connected as well.
This means that users can prevent "usermod -m" from completing if their
home directories contain at least one fifo.
Use *at() functions to pin the directory operating in to avoid being
redirected by unprivileged users replacing parts of paths by symlinks to
privileged files.
Introduce a path_info struct with the full path and dirfd and name
information for *at() functions, since the full path is needed for link
resolution, SELinux label lookup and ACL attributes.
Allow the compiler to verify the format string against the supplied
arguments.
chage.c:239:51: warning: format not a string literal, format string not checked [-Wformat-nonliteral]
239 | (void) strftime (buf, sizeof buf, format, tp);
| ^~~~~~
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>
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>
libmisc/copydir.c, lib/selinux.c: Move set_selinux_file_context()
and reset_selinux_file_context() from libmisc/copydir.c to
lib/selinux.c.
* lib/commonio.c: Use set_selinux_file_context() and
reset_selinux_file_context() instead of using the existing
database SELinux context to set the context for the newly created
files.
* libmisc/copydir.c: Missing parenthesis in comment.
* libmisc/chowndir.c: Fixed memory leak on failed realloc().
* libmisc/chowndir.c: Make sure the buffer for the path is large
enough.
* libmisc/remove_tree.c: Remove check for NULL before free().
selinux_file_context renamed set_selinux_file_context.
* lib/protoypes.h, libmisc/copydir.c, src/useradd.c:
Added reset_selinux_file_context.
* src/useradd.c: Check the return value of
set_selinux_file_context and reset_selinux_file_context.
* libmisc/copydir.c: Check the return value of
reset_selinux_file_context.
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.
copy the extended attributes (the SELinux context is hence reset)
* src/usermod.c: Copy the extended attributes.
* src/useradd.c: Only reset the SELinux context.
* src/useradd.c: spool is a constant string.
* src/useradd.c: Set the new copy_tree's paramater 'copy_root' to false
2010-04-04 Nicolas François <nicolas.francois@centraliens.net>
* src/usermod.c: move_home() is only called if mflg is set.
* src/usermod.c: Fail is -m is provided but the old home directory
is not a directory.
* src/usermod.c: Use the previous improvement of copy_tree to
provide better error diagnosis.
* src/usermod.c: When rename() is used, also change the ownership.
* src/usermod.c: Do not change the ownership of the root directory
twice.
* src/usermod.c: When -u is provided, only change the ownership of
the home directory if it is a directory.
* src/usermod.c: Also change ownerships when -g is used.
2010-04-04 Nicolas François <nicolas.francois@centraliens.net>
* lib/prototypes.h, libmisc/copydir.c: Add the old UID and GID to
copy_tree to detect when ownership shall be changed.
* libmisc/copydir.c: Document the behavior when the IDs are set to
-1.
* lib/prototypes.h, libmisc/copydir.c (copy_tree): Add parameter
copy_root.
* libmisc/copydir.c: error() and ctx can be static.
* libmisc/copydir.c (copy_hardlink): Remove parameter src.
2010-04-04 Nicolas François <nicolas.francois@centraliens.net>
* libmisc/chowndir.c: Dynamically allocate memory to support
path longer than 1024 characters.
* libmisc/chowndir.c: Fix typos in documentation.
* libmisc/chowndir.c: Support and document the behavior when a old
or new ID is set to -1.
* libmisc/chowndir.c: Improved error detection when chown fails.
* libmisc/chowndir.c: Harmonize error handling strategy when an
error occurs: stop changing ownership as soon as an error was
detected.
no more used.
* lib/groupmem.c: Limit the scope of variable i.
* lib/shadow.c: Avoid implicit conversion of pointers and integers
to booleans.
* lib/shadow.c: Added brackets.
* libmisc/limits.c: Limit the scope of variable tmpmask.
* libmisc/copydir.c: Close opened file on failure.
* libmisc/loginprompt.c: Limit the scope of variable envc.
* libmisc/find_new_uid.c, libmisc/find_new_gid.c: Limit the scope
of variable id.
* NEWS: Add support for TCB.
* lib/tcbfuncs.h, lib/tcbfuncs.c, lib/Makefile.am: New library to
support TCB.
* lib/prototypes, libmisc/copydir.c (remove_tree): Add boolean
parameter remove_root.
* configure.in: Add conditional WITH_TCB.
* src/userdel.c, src/usermod.c: Add support for TCB. Update call to
remove_tree().
* src/pwconv.c, src/pwunconv.c: Should not be used with TCB enabled.
* src/vipw.c: Add support for TCB. Update call to remove_tree().
* src/useradd.c: Add support for TCB. Open the shadow file outside
of open_files().
* src/chage.c: Add support for TCB.
* src/Makefile.am: Install passwd sgid shadow when TCB is enabled.
* lib/getdefs.c, man/vipw.8.xml, man/login.defs.5.xml,
man/login.defs/TCB_AUTH_GROUP.xml, man/login.defs/USE_TCB.xml,
man/login.defs/TCB_SYMLINKS.xml, man/generate_mans.mak,
man/generate_mans.deps, man/Makefile.am: New configuration
parameters: TCB_AUTH_GROUP, TCB_SYMLINKS, USE_TCB.
* lib/shadowio.c, lib/commonio.c: Add support for TCB.
with a NULL argument.
* src/useradd.c: Replace PATH_MAX by a fixed constant. The buffer
was not meant as a storage for a path.
* src/useradd.c, src/newusers.c, src/chpasswd.c: Better detection
of fgets errors. Lines shall end with a \n, unless we reached the
end of file.
* libmisc/copydir.c: Avoid PATH_MAX. Support file paths with any
length. Added readlink_malloc().
* libmisc/copydir.c: Added assert to help splint.
* libmisc/copydir.c: Free allocated structures in cas of failure.
* libmisc/copydir.c: Avoid implicit conversion of pointers to
booleans.
* libmisc/copydir.c: Use buffers of size PATH_MAX instead of 1024
for filenames.
* libmisc/copydir.c: Use fchmod and fchown to change the mode of
the opened file.
* libmisc/copydir.c: Indicate the mode to open(), even if we chmod
later.
SELinux user for user's login.
* NEWS, src/usermod.c, man/usermod.8.xml: Likewise.
* libmisc/system.c, libmisc/Makefile.am, lib/prototypes.h: Added
safe_system(). Used to run semanage.
* lib/prototypes.h, libmisc/copydir.c: Make a
selinux_file_context() an extern function.
* libmisc/copydir.c: Reset SELinux to create files with default
contexts at the end of copy_tree().
* NEWS, src/userdel.c: Delete the SELinux user mapping for user's
login.
* configure.in, libmisc/copydir.c: futimes() and lutimes() are not
standard. Check if they are implemented before using them. Do not
set the time of links if lutimes() does not exist, and use
utimes() as a replacement for futimes().
prototypes.
* libmisc/copydir.c: Use a size_t for the length of strings.
* libmisc/copydir.c: Cast the return value of malloc().
* libmisc/copydir.c: The size argument of write() is a size_t.
followed by rmdir to remove the directory itself, delete also the
root directory in remove_tree.
* src/userdel.c, src/usermod.c: Do not call rmdir after
remove_tree.
with post increments (x++), use of integers as booleans, and
explicitly mark blocks with brackets.
* libmisc/copydir.c: Likewise.
* libmisc/fields.c: Add comments.
* libmisc/copydir.c: Mark function whose return value is not
checked as such.
* libmisc/copydir.c (remove_tree): Make sure unlink is successful
when removing files.
