Setting time by seconds or microseconds may cause unexpected effects
especially if sysctl vfs.timestamp_precision=3 (not default).
Calling the obsolete functions with NULL timestamps is acceptable.
This support appears to have been documented in nsswitch.conf(5) for some
time. The implementation adds two NSS netgroup providers to libc. The
default, compat, provides the behaviour documented in netgroup(5), so this
change does not make any user-visible behaviour changes. A files provider
is also implemented.
innetgr(3) is implemented as an optional NSS method so that providers such
as NIS which are able to implement efficient reverse lookup can do so.
A fallback implementation is used otherwise. getnetgrent_r(3) is added for
convenience and to provide compatibility with glibc and Solaris.
With a small patch to net/nss_ldap, it's possible to specify an ldap
netgroup provider, allowing one to query nisNetgroupTriple entries.
Sponsored by: EMC / Isilon Storage Division
Handle an empty result from yp_match() by returning NULL, which is
consistent with the handling of an empty netgroup in /etc/netgroup.
setnetgrent(3) has no return value, so there is no particular need to
distinguish this case from an error.
PR: 26486
MFC after: 2 weeks
This adds stravis() and some new encoding flags VIS_SHELL, VIS_META,
and VIS_NOLOCALE.
Assorted cleanups and fixes includeing a manpage typo[0].
PR: 210013 [0]
Submitted by: pi [0]
If malloc() fails to allocate linep, then free olinep (if it exists)
before returning to avoid a memory leak.
Reported by: Coverity
CID: 1016716
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D6755
When collation support was brought in, the second and third
arguments in __collate_range_cmp() were changed from int to
wchar_t, breaking the ABI. Change them to a "char" type which
makes more sense and keeps the ABI compatible.
Also introduce __wcollate_range_cmp() which does work with wide
characters. This function is used only internally in libc so
we don't export it. Use the new function in glob(3), fnmatch(3),
and regexec(3).
PR: 179721
Suggested by: ache. jilles
MFC after: 3 weeks (perhaps partial only)
POSIX 2008 added the psignal() function which has already been part of
the BSDs for a long time. The only difference is, the POSIX version uses
an 'int' for the signal number, unlike our version which uses an
'unsigned int'. Fix up the function to use an 'int'. This should not
affect the ABI.
intention of the POSIX IEEE Std 1003.1TM-2008/Cor 1-2013.
A robust mutex is guaranteed to be cleared by the system upon either
thread or process owner termination while the mutex is held. The next
mutex locker is then notified about inconsistent mutex state and can
execute (or abandon) corrective actions.
The patch mostly consists of small changes here and there, adding
neccessary checks for the inconsistent and abandoned conditions into
existing paths. Additionally, the thread exit handler was extended to
iterate over the userspace-maintained list of owned robust mutexes,
unlocking and marking as terminated each of them.
The list of owned robust mutexes cannot be maintained atomically
synchronous with the mutex lock state (it is possible in kernel, but
is too expensive). Instead, for the duration of lock or unlock
operation, the current mutex is remembered in a special slot that is
also checked by the kernel at thread termination.
Kernel must be aware about the per-thread location of the heads of
robust mutex lists and the current active mutex slot. When a thread
touches a robust mutex for the first time, a new umtx op syscall is
issued which informs about location of lists heads.
The umtx sleep queues for PP and PI mutexes are split between
non-robust and robust.
Somewhat unrelated changes in the patch:
1. Style.
2. The fix for proper tdfind() call use in umtxq_sleep_pi() for shared
pi mutexes.
3. Removal of the userspace struct pthread_mutex m_owner field.
4. The sysctl kern.ipc.umtx_vnode_persistent is added, which controls
the lifetime of the shared mutex associated with a vnode' page.
Reviewed by: jilles (previous version, supposedly the objection was fixed)
Discussed with: brooks, Martin Simmons <martin@lispworks.com> (some aspects)
Tested by: pho
Sponsored by: The FreeBSD Foundation
According to style(9):
> normally, include <sys/types.h> OR <sys/param.h>, but not both.
(<sys/param.h> already includes <sys/types.h> when LOCORE is not defined).
We have an nitems() macro in the <sys/param.h> header that is
convenient to re-use as it makes things easier to read.
Given that it is available already without adding additional
headers and other parts of libc already use it, extend a bit
more its use.
In r103767 the kern.ps_strings sysctl was added as the preferred way to
locate the ps_strings struct and is available in any FreeBSD release
supported within the last decade.
Reviewed by: kib
While here also cleanup some surrounding code; particularly
drop some malloc() casts.
Found with devel/coccinelle.
Reviewed by: bde (previous version - all new bugs are mine)
do not participate in the global symbols namespace, but rtld locks are
still replaced and functions are interposed. In particular,
__pthread_map_stacks_exec is resolved to the libc version. If a
library is loaded later, which requires adjustment of the stack
protection mode, rtld calls into libc __pthread_map_stacks_exec due to
the symbols scope. The libc version might recurse into binder and
recursively acquire rtld bind lock, causing the hang.
Make libc __pthread_map_stacks_exec() interposed, which synchronizes
rtld locks and version of the stack exec hook when libthr loaded,
regardless of the symbol scope control or symbol resolution order.
The __pthread_map_stacks_exec() symbol is removed from the private
version in libthr since libc symbol now operates correctly in presence
of libthr.
Reported and tested by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
wraps sendmsg(2) and recvmsg(2) into batch send and receive operation.
The goal of this implementation is only to provide API compatibility
with Linux.
The cancellation behaviour of the functions is not quite right, but
due to relative rare use of cancellation it is considered acceptable
comparing with the complexity of the correct implementation. If
functions are reimplemented as syscalls, the fix would come almost
trivial. The direct use of the syscall trampolines instead of libc
wrappers for sendmsg(2) and recvmsg(2) is to avoid data loss on
cancellation.
Submitted by: Boris Astardzhiev <boris.astardzhiev@gmail.com>
Discussed with: jilles (cancellation behaviour)
MFC after: 1 month
by application closing its stdin (i.e. STDIN_FILENO) prior to
calling readpassphrase WITHOUT setting RPP_STDIN. What happens
then is that the readpassphrase would open /dev/tty, and since
file descriptors are reused, the call would return first unused
fd, which is 0 which is also STDIN_FILENO. Then due to the usage
of "input != STDIN_FILENO" in the code to do its logic, that
would result in noecho flags not set on that file descriptor,
which was original issue I've been trying to fix.
In addition to that, the readpassphrase() would leak file
descriptor on its way out, so fix that one as well.
This problem can be tested with:
$ ssh-add - < /tmp/myprivate.key
The password will not be hidden as it should and ktrace will
show:
53326 ssh-add CALL open(0x80142443c,0x100002<O_RDWR|O_CLOEXEC>,<unused>0x165f030)
53326 ssh-add NAMI "/dev/tty"
53326 ssh-add RET open 0
53326 ssh-add CALL sigprocmask(SIG_SETMASK,0x802eb1324,0x7fffffffd5e0)
53326 ssh-add RET sigprocmask 0
53326 ssh-add CALL sigaction(SIGALRM,0x7fffffffd630,0x7fffffffd610)
Instead of:
57690 ssh-add CALL open(0x80142443c,0x100002<O_RDWR|O_CLOEXEC>,<unused>0x165f030)
57690 ssh-add NAMI "/dev/tty"
57690 ssh-add RET open 4
57690 ssh-add CALL ioctl(0x4,TIOCGETA,0x7fffffffd860)
57690 ssh-add RET ioctl 0
57690 ssh-add CALL ioctl(0x4,TIOCSETAF,0x7fffffffd680)
57690 ssh-add RET ioctl 0
57690 ssh-add CALL sigprocmask(SIG_SETMASK,0x802eb1324,0x7fffffffd620)
57690 ssh-add RET sigprocmask 0
57690 ssh-add CALL sigaction(SIGALRM,0x7fffffffd670,0x7fffffffd650)
For the case when the key is read from the file.
Technically this can also be workaround'ed at the application side
by not closing the STDIN_FILENO in the first place, but readpassphrase(3)
doesn't need to make any assumptions about that. Plus the file descriptor
leak confirms that this is an oversight, rather than a deliberate behaviour.
MFC after: 1 week
This bug could be reproduced easily by calling sem_open() with O_CREAT |
O_EXCL on a semaphore that is already open in the process. The struct
sem_nameinfo would be freed while still in sem_list and later calls to
sem_open() or sem_close() could access freed memory.
PR: 206396
MFC after: 5 days
Set _PATH_DEFPATH to
/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin. This is the
path in the default class in the default /etc/login.conf,
excluding ~/bin which would not be expanded properly in a string
constant.
For normal logins, _PATH_DEFPATH is overridden by /etc/login.conf,
~/.login_conf or shell startup files. _PATH_DEFPATH is still used as a
default by execlp(), execvp(), posix_spawnp() and sh if PATH is not set, and
by cron. Especially the latter is a common trap (most recently in PR
204813).
PR: 204813
Reviewed by: secteam (delphij), alfred
i386 is the only current FreeBSD architecture that ever used a.out
format.
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D4687
Tracking these leads to situations where meta mode will consider the
file to be out of date if /bin/sh or /bin/ln are newer than the source
file. There's no reason for meta mode to do this as make is already
handling the rebuild dependency fine.
Sponsored by: EMC / Isilon Storage Division
Move fdopen() up near other resource allocation like malloc(); do proper
deallocation on failure later on in the function.
Submitted by: Ramachandra Topannavar <rtopannavar@panasas.com>
Reviewed by: jilles
Approved by: jhb (mentor)
MFC after: 2 weeks
Sponsored by: Panasas, Inc.
Differential Revision: https://reviews.freebsd.org/D4126
M lib/libc/gen/popen.c
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
Shell syntax is too complicated to detect command substitution and unquoted
operators reliably without implementing much of sh's parser. Therefore, have
sh do this detection.
While changing sh's support anyway, also read input from a pipe instead of
arguments to avoid {ARG_MAX} limits and improve privacy, and output count
and length using 16 instead of 8 digits.
The basic concept is:
execl("/bin/sh", "sh", "-c", "freebsd_wordexp ${1:+\"$1\"} -f "$2",
"", flags & WRDE_NOCMD ? "-p" : "", <pipe with words>);
The WRDE_BADCHAR error is still implemented in libc. POSIX requires us to
fail strings containing unquoted braces with code WRDE_BADCHAR. Since this
is normally not a syntax error in sh, there is still a need for checking
code in libc, we_check().
The new we_check() is an optimistic check that all the characters
<newline> | & ; < > ( ) { }
are quoted. To avoid duplicating too much sh logic, such characters are
permitted when quoting characters are seen, even if the quoting characters
may themselves be quoted. This code reports all WRDE_BADCHAR errors; bad
characters that get past it and are a syntax error in sh return WRDE_SYNTAX.
Although many implementations of WRDE_NOCMD erroneously allow some command
substitutions (and ours even documented this), there appears to be code that
relies on its security (codesearch.debian.net shows quite a few uses).
Passing untrusted data to wordexp() still exposes a denial of service
possibility and a fairly large attack surface.
Reviewed by: wblock (man page only)
MFC after: 2 weeks
Relnotes: yes
Security: fixes command execution with wordexp(untrusted, WRDE_NOCMD)
The old code was exponential in the number of asterisks in the pattern.
However, once a match has been found upto the next asterisk, the previous
asterisks are no longer relevant.
