utilities is done by calling gr_addgid() for each group to be
added (usually found by traversing /etc/group) then calling the
setgroups() system call after the group set has been created.
The gr_addgid() function (helpfully?) deduplicates the addition
of group members. So, if you call it to add a group member that
already exists, it is just dropped. Because group[0] is the
effective group-ID and is over-written when a setgid program
is run, The value in group[0] is usually duplicated so that
group value is not lost when a setgid program is run.
Historically this happened because the group value indicated
in the password file also appears in /etc/group (e.g., if you
are group staff in the password file, you will also appear in
the staff line in /etc/group). But, with the addition of the
deduplication, the attempt to add group staff was lost because
it already appeared in group[0]. So, the fix is to deduplicate
starting from group[1] which allows a duplicate of the entry in
group[0], but not in later entries.
There is some confusion about the setgroups system call because in
BSD it has (always) set the entire group including the egid group
(in group[0]). However, in Linux, it skips over group[0] and starts
setting from group[1]. See this comment from linux_setgroups:
/*
* cr_groups[0] holds egid. Setting the whole set from
* the supplied set will cause egid to be changed too.
* Keep cr_groups[0] unchanged to prevent that.
*/
To make it clear what the BSD setgroups system call does, I
added the following paragraph to the setgroups(2) manual page:
The first entry of the group array (gidset[0]) is used as the effective
group-ID for the process. This entry is over-written when a setgid
program is run. To avoid losing access to the privileges of the
gidset[0] entry, it should be duplicated later in the group array.
By convention, this happens because the group value indicated in the
password file also appears in /etc/group. The group value in the
password file is placed in gidset[0] and that value then gets added a
second time when the /etc/group file is scanned to create the group set.
Reported by: Paul McMath paulm at tetrardus.net
Reviewed by: kib
MFC after: 2 weeks
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Just like with freelocale(3), I haven't been able to find any piece of
code that actually makes use of this function's return value, both in
base and in ports. The reason for this is that FreeBSD seems to be the
only operating system to have such a prototype. This is why I'm deciding
to not use symbol versioning for this.
It does seem that the pw(8) utility depends on the function's typing and
already had a switch in place to toggle between the FreeBSD and POSIX
variant of this function. Clean this up by always expecting the POSIX
variant.
There is also a single port that has a couple of local declarations of
setgrent(3) that need to be patched up. This is in the process of being
fixed.
PR: 211394 (exp-run)
MK_NIS == no by converting `i` back to an int, and instead cast the loop
comparison to `int`
The loop comparison is iterating the len(ns_dtab)-1, because
the last element is the sentinel tuple { NULL, NULL, NULL, }, so when
both HESOID and NIS are off, len(ns_dtab)-1 == 1 - 1 == 0, and the loop
is skipped because the expression is tautologically false
While here, convert `(sizeof(x) / sizeof(x[0]))` to `nitems(x)`
Tested with: clang 3.7.0, gcc 4.2.1, and gcc 4.9.4 [*] with MK_NIS={no,yes}
and by running bash -lc 'id -u && id -g && id'
* gcc 4.9.4 needs another patch in order for the compile to succeed
with -Werror with lib/libc/gen/getgrent.c
Reported by: jhibbits
As a followup to r278363, there is one more case where
stayopen can be accessed uninitialized, but even after
swapping arguments, access is possible in some other
cases so prevent it completely by initializing stayopen.
CID: 1018729
CID: 1018732
In a couple of cases a variable "stayopen" can be checked
unitialized. This is of no danger as the complementary
condition is false but prevent the access by switching
the checks.
CID: 1018729
CID: 1018732
when particular function can't be found in nsswitch-module. For
example, getgrouplist(3) will use module-supplied 'getgroupmembership'
function (which can work in an optimal way for such source as LDAP) and
will fall back to the stanard iterate-through-all-groups implementation
otherwise.
PR: ports/114655
Submitted by: Michael Hanselmann <freebsd AT hansmi DOT ch>
Reviewed by: brooks (mentor)
in rev. 1.34. Mainly I missed the fact that the buffer is used for two
purposes:
1) storing a group line from the group file;
2) __gr_parse_entry() parses the buffer and tries to put the group
members to the remaining part of the buffer and can fail if there
is no enough room for them.
Re-arrange the buffer size checks to account the latter case.
Submitted by: Kirk R Webb
MFC after: 2 weeks
If the initial buffer size (1KB) for the given group line is not big
enough, reset the offset. It helps to do not miss this line when
getrg() reallocates the larger buffer and tries to parse the line again.
PR: bin/52433, kern/55031, bin/83696, misc/97640, misc/98111
Submitted by: bsw71@mail.ru, Philip M. Gollucci, Justin Erenkrantz
Glanced at: nectar
MFC after: 1 month
technique) so that we don't wind up calling into an application's
version if the application defines them.
Inspired by: qpopper's interfering and buggy version of strlcpy
setgrent, and endgrent also. (The previous NSS implementation used to
simply twiddle the internal data of the various modules directly.)
A symptom (group list set incorrectly in sshd) was
Reported by: Glenn Johnson <gjohnson@srrc.ars.usda.gov>
Sponsored by: DARPA, Network Associates Laboratories
Correct a bug that should have wreaked havoc everywhere, but for
some reason only bit unlucky people who use `-march' optimizations.
The compiler cannot assist one in distinguishing between the two
function calls below.
int nsdispatch(void *, ...);
void *discard;
nsdispatch(&discard, ...); /* correct .. no, really! */
nsdispatch(discard, ...); /* Boom */
Robin provided me with a debugging environment in which I could see
what was going on.
Badness when using CPUTYPE was
Reported by: "Robin P. Blanchard" <Robin.Blanchard@gactr.uga.edu>
Reported by: nork
Sponsored by: DARPA, Network Associates Laboratories
would result in an incorrectly terminated grouplist.
login(1) crashes
Reported by: Morten Rodal <morten@rodal.no>,
Matthias Schuendehuette <msch@snafu.de>
family of functions using the new nsdispatch(3) core. Remove
arbitrary size limits when using the thread-safe versions.
= Re-implement the traditional getpwent(3)/getgrent(3) functions on
top of the thread-safe versions.
= Update the on-disk format of the hashed version of the passwd(5)
databases to allow for versioned entries. The legacy version is
`3'. (Don't ask.)
= Add support for version `4' entries in the passwd(5) database.
Entries in this format are identical to version 3 entries except
that all integers are stored as 32-bit integers in network byte
order (big endian).
= pwd_mkdb is updated to generate both version 3 and version 4
entries.
Sponsored by: DARPA, Network Associates Laboratories
commit.
Fixed related style bugs:
basename.c: misplaced '#if 0'
dirname.c: misplaced '#if 0'
getgrent.c: missing '#if 0', and tab lossage in vendor id (the previous
commit fixed the complete corruption of the vendor id but
lost a tab)
getpwent.c: missing '#if 0'
configure FreeBSD so that various databases such as passwd and group can be
looked up using flat files, NIS, or Hesiod.
= Hesiod has been added to libc (see hesiod(3)).
= A library routine for parsing nsswitch.conf and invoking callback
functions as specified has been added to libc (see nsdispatch(3)).
= The following C library functions have been modified to use nsdispatch:
. getgrent, getgrnam, getgrgid
. getpwent, getpwnam, getpwuid
. getusershell
. getaddrinfo
. gethostbyname, gethostbyname2, gethostbyaddr
. getnetbyname, getnetbyaddr
. getipnodebyname, getipnodebyaddr, getnodebyname, getnodebyaddr
= host.conf has been removed from src/etc. rc.network has been modified
to warn that host.conf is no longer used at boot time. In addition, if
there is a host.conf but no nsswitch.conf, the latter is created at boot
time from the former.
Obtained from: NetBSD
In some cases replace if (a == null) a = malloc(x); else a =
realloc(a, x); with simple reallocf(a, x). Per ANSI-C, this is
guaranteed to be the same thing.
I've been running these on my system here w/o ill effects for some
time. However, the CTM-express is at part 6 of 34 for the CAM
changes, so I've not been able to do a build world with the CAM in the
tree with these changes. Shouldn't impact anything, but...
The character `#' introduces a comment. Leading spaces and tabs are
ignored: '^[ \t]*#.*\n$'
Count an empty line - only spaces, tabs or newline - also as a comment.
(to be compatibel with password database comments). '^[ \t]*\n$'
- getpwent:
o adjunctbuf should be NUL terminated after copying
o _pw_breakout_yp() needs to know the length of the buffer returned
from YP so it can properly NUL terminate its local buffer.
- getgrent:
o YP buffers should be YPMAXRECORD + 2 bytes long and NUL terminated.
(Previously they were hardcoded to 1024 bytes.)
- getnetgrent:
o YP data should be copied with snprintf(), not sprintf()
These are 2.2 candidates. I will wait a few days to make sure these don't
break anything and then, if there are no objections, move them to the 2.2
branch.
line length limit anymore - now 500 members or 5000 members are
possible. For security group lines longer than 256K will be count as
an error. 256K should be enough for 65536 users.
Support comments (lines that begin with a #) if compiled with
option -DGROUP_IGNORE_COMMENTS.
Fortunately it seems that all system utilities which use getgrent()
functions are dynamically linked executables. So you need only
rebuild libc.so.3.0 if you want this change. Note: if you have
an old X server which depend on libc.so.2.* you should rebuild
libc.so.2.* too.
Not a 2.2 candidate.
- In some cases, we don't properly resolve _all_ possible group memberships.
If a user is a member of both local and NIS groups, we sometimes lose some
of the membership info from NIS. (Reported by: Thorsten Kukuk
<kukuk@uni-paderborn.de>)
- Make NIS +groupname overrides actually work the way the SunOS group(5)
man page says they should (make them work for all cases: getgrent(),
getgrnam() and getgrgid()).
- When not compiled with -DYP, grscan() should ignore entries that
begin with a '+'. When compiled _with_ -DYP, grscan() should ignore
+groupname entries that don't refer to real NIS groups.
- Remove redundant redeclaration of fgets(), strsep() and index() inside
grscan(). We already #include all the right header files for these.
Note: -groupname exclusion as specified in the Sun documentation still
isn't supported. This'll be a 2.2 addition. Right now I just want this
stuff to work.
the group map after encountering a badly formatted entry.
getpwent.c: same as above for _nextyppass(), and also turn a couple of
sprintf()s into snprintf()s to avoid potential buffer overruns. (The
other day I nearly went mad because of a username in my NIS database
that's actually 9 characters long instead of 8. Stuffing a 9-character
username into an 8-character buffer can do some strange things.)
(This reminds me: I hope somebody's planning to fix the buffer overrun
security hole in syslog(3) before 2.1 ships.)
seperate function to avoid duplication. Also fix getpwent() a
small bit to properly handle the case where the magic NIS '+'
entry appears before the end of the password file.
getgrent.c: be a little more SunOS-ish. Make it look like the NIS
group map is 'inserted' at the the point(s) where the magic NIS '+'
entry/entries appear.
getgrent: fix a file descriptor leak: remember to close the netgroup
file after we determine that we're using NIS-only innetgr() lookups.
last night:
_gr_breakout_yp() doesn't check for badly formatted NIS group entries.
For example, a bogus entry like this:
bootp::user1,user2,user3
will lead to a null pointer dereference and a SEGV (note that the GID
field is missing -- this results in one of the strsep(&result, ":")
returning NULL). The symtpom of this problem is programs dumping
core left and right the moment you add a + entry to /etc/group.
Note that while this is similar to an earlier bug, it's caused by a
different set of circumstances.
The fix is to check for the NULL pointers and have _gr_breakout_yp()
punt and return a failure code if it catches one. This is more or
less the behavior of SunOS: if a bad NIS group entry is encountered,
it's silently ignored. I don't think our standard (non-NIS) group
parsing code behaves the same way. It doesn't crash though, so I'm
citing the 'it ain't broken, don't fix it' rule and leaving it alone.
I'll probably have to add similar checks to _pw_breakout_yp() in
getpwent.c to ward off the same problems. It's rare that bad NIS
map entries like this occur, but we should handle them gracefully
when they do.
- If you take the wheel entry out of /etc/group and turn on NIS,
the '+:*::' line is incorrectly flagged as the entry for wheel (the
empty gid section is translated to 0), hence getgrgid() returns '+'
as the name of the group instead of 'wheel.'
- Using just '+:' as the 'turn on NIS' switch in /etc/group makes
getgrgid() dump core because of a null pointer dereference. (Last
time I was in here, I foolishly assumed that fixing the core dump
problems with getgrnam() and getgrent() would fix getgrgid() too.
Silly me.)
add #includes for YP headers when compiling with -DYP to avoid some implicit
declarations.
getgrent.c & getnetgrent.c: add some #includes to avoid implicit declarations
of YP functions.
by heading off possible null pointer dereferences in grscan(). Also
change getgrnam() slightly to properly handle the change: if grscan()
returns an rval of 1 and leaves a '+' in the gr_name field and YP is
enabled, poll the YP group.byname map before giving up. This should
insure that we make every effort to find a match in the local and
YP group databases before bailing out.
