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.
comment above, POSIX_SPAWN_SETSIGMASK and POSIX_SPAWN_SETSIGDEF
handlers used libthr interposed functions instead of syscalls.
Noted by: jilles
Sponsored by: The FreeBSD Foundation
MFC after: 6 days
are aliases for the syscall stubs and are plt-interposed, to the
libc-private aliases of internally interposed sigprocmask() etc.
Since e.g. _sigaction is not interposed by libthr, calling signal()
removes thr_sighandler() from the handler slot etc. The result was
breaking signal semantic and rtld locking.
The added __libc_sigprocmask and other symbols are hidden, they are
not exported and cannot be called through PLT. The setjmp/longjmp
functions for x86 were changed to use direct calls, and since
PIC_PROLOGUE only needed for functional PLT indirection on i386, it is
removed as well.
The PowerPC bug of calling the syscall directly in the setjmp/longjmp
implementation is kept as is.
Reported by: Pete French <petefrench@ingresso.co.uk>
Tested by: Michiel Boland <boland37@xs4all.nl>
Reviewed by: jilles (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Distinguish between WRDE_BADVAL and WRDE_SYNTAX based on when the error
occurred (parsing or execution), not based on whether WRDE_UNDEF was passed.
Also, return WRDE_NOSPACE for a few more unexpected results from sh.
The functionality of the wordexp builtin is easily replaced using normal
shell code, although performance is slightly worse.
This does not mean that wordexp() will remain shell-independent -- a fully
reliable implementation of WRDE_NOCMD is really only possible using
extensions to the shell, or by adding much of the shell's code to libc.
the 'user' sysctl tree, which have all been coming back 0 or empty
since r240176.
Differential Revision: https://reviews.freebsd.org/D2945
Reviewed by: sbruno
Approved by: jmallett (mentor)
MFC after: 3 days
as seek to teh last location saved will still work. This is needed for Samba
to be able to correctly handle delete requests from windows. This does not
completely fix seekdir when deletes are present but fixes the worst of the
problems. The real solution must involve some changes to the API for eh VFS
and getdirentries(2).
Obtained from: Panzura inc
MFC after: 1 week
kernel, but keep explanation of the old ps_strings structure to make
it clear what sanity check tries to accomplish.
Noted by: Oliver Pinter <oliver.pinter@hardenedbsd.org>
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
waitid() function is required to be cancellable by the standard. The
wait6() and ppoll() follow the other syscalls in their groups.
Reviewed by: jhb, jilles (previous versions)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
dependent functions have been implemented, but this is enough for world.
Differential Revision: https://reviews.freebsd.org/D2132
Reviewed by: emaste
Sponsored by: The FreeBSD Foundation
When following symlinks, fts returned FTS_SLNONE when fstatat(flag=0)
failed, but a subsequent fstatat(flag=AT_SYMLINK_NOFOLLOW) succeeded. This
incorrectly triggered if a filename existed to be read from the directory,
was deleted before the fstatat(flag=0) and created again after the
fstatat(flag=0).
Fix this by only returning FTS_SLNONE if the result from
fstatat(flag=AT_SYMLINK_NOFOLLOW) is actually a symlink. If it is not a
symlink, treat it as if fstatat(flag=0) succeeded.
PR: 196724
Reported and tested by: pho
MFC after: 1 week
Per Austin group issue #884, sh should not import IFS from the environment
but always set it to $' \t\n'. For wordexp(), however, it is documented and
useful for it to use IFS from the environment.
Since sh currently imports IFS from the environment, this change has no
functional effect.
MFC after: 1 week
Commit r279154 changed the API and ABI significantly, and {NZERO} is still
wrong.
Also, preserve errno on success instead of setting it to 0.
PR: 189821
Reported by: bde
Relnotes: yes
Our man page already documented this partially but now
we have some consistent behavior.
PR: 136669
Obtained from: NetBSD (CVS rev. 1.31, 1.33)
Relnotes: yes
MFC after: 3 weeks
rlim_t is at least as large as long, so we don't need the
extra variable to keep the intermediate step. We don't
need the volatile either.
The code was tested on i386 and amd64.
Suggested by: bde
X-MFC with: r278803
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
The existing implementation had a broken comparison that could
overflow and return confusing values. Replace this with a check
that avoids the overflow before it happens.
Consistently return a maximum value also on the case of negative
arguments since negative is considered an overflow and means
infinity for our current setrlimit().
New revamped version is credited to Bruce Evans.
CID: 1199295
MFC after: 1 week
particular, stdio locking was affected.
Reported and tested by: "Matthew D. Fuller" <fullermd@over-yonder.net>
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
The existing implementation had a broken comparison that could overflow.
Replace this with a check that avoids the overflow before it happens.
Consistently return a maximum value also on the case of negative
arguments since negative is considered an overflow and means
infinity for our current setrlimit().
Discussed with: bde (rather extensively)
CID: 1199295
MFC after: 1 week
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
This was a local addition to the original change from NetBSD.
Being this libc there is some chance for it to interfere with
user's cget*() functions usage. The memory leak was finely
plugged by r278300.
Pointed out by: ache
Only i386 and amd64 provide a non-trivial __getcontextx(). Use a common
trivial implementation in gen/ for other architectures, rather than
copying the file to each MD subdirectory.
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D1472
cancellation-handling code in the libthr. Translate some syscalls
into their more generic counterpart, and remove translated syscalls
from the table.
List of the affected syscalls:
creat, open -> openat
raise -> thr_kill
sleep, usleep -> nanosleep
pause -> sigsuspend
wait, wait3, waitpid -> wait4
Suggested and reviewed by: jilles (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
(or loading a dso linked to libthr.so into process which was not
linked against threading library).
- Remove libthr interposers of the libc functions, including
__error(). Instead, functions calls are indirected through the
interposing table, similar to how pthread stubs in libc are already
done. Libc by default points either to syscall trampolines or to
existing libc implementations. On libthr load, libthr rewrites the
pointers to the cancellable implementations already in libthr. The
interposition table is separate from pthreads stubs indirection
table to not pull pthreads stubs into static binaries.
- Postpone the malloc(3) internal mutexes initialization until libthr
is loaded. This avoids recursion between calloc(3) and static
pthread_mutex_t initialization.
- Reinstall signal handlers with wrapper on libthr load. The
_rtld_is_dlopened(3) is used to avoid useless calls to sigaction(2)
when libthr is statically referenced from the main binary.
In the process, fix openat(2), swapcontext(2) and setcontext(2)
interposing. The libc symbols were exported at different versions
than libthr interposers. Export both libc and libthr versions from
libc now, with default set to the higher version from libthr.
Remove unused and disconnected swapcontext(3) userspace implementation
from libc/gen.
No objections from: deischen
Tested by: pho, antoine (exp-run) (previous versions)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
In r228193 the test of CONNPRIV have been moved to before the _usleep
and send in vsyslog(). When syslogd restarts, this would prevent the
message being logged after the disconnect/connect dance for
scenario #1.
PR: 194751
Submitted by: Peter Creath <pjcreath+freebsd gmail com>
Reviewed By: glebius
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D1227
It is automatically set when -fPIC is passed to the compiler.
Reviewed by: dim, kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D1179
in a separate word from the _count. This does not permit both items to
be updated atomically in a portable manner. As a result, sem_post()
must always perform a system call to safely clear _has_waiters.
This change removes the _has_waiters field and instead uses the high bit
of _count as the _has_waiters flag. A new umtx object type (_usem2) and
two new umtx operations are added (SEM_WAIT2 and SEM_WAKE2) to implement
these semantics. The older operations are still supported under the
COMPAT_FREEBSD9/10 options. The POSIX semaphore API in libc has
been updated to use the new implementation. Note that the new
implementation is not compatible with the previous implementation.
However, this only affects static binaries (which cannot be helped by
symbol versioning). Binaries using a dynamic libc will continue to work
fine. SEM_MAGIC has been bumped so that mismatched binaries will error
rather than corrupting a shared semaphore. In addition, a padding field
has been added to sem_t so that it remains the same size.
Differential Revision: https://reviews.freebsd.org/D961
Reported by: adrian
Reviewed by: kib, jilles (earlier version)
Sponsored by: Norse
previous seek location was 0. Without this, readdir() would see
dd_loc of zero and call getdirentries() which would start reading
entries at the current seek location of the directory ignoring the
first batch of entries. Also, rewinddir() should always seek so that
it reads the directory from the beginning to get updated entries.
PR: 192935
Reported by: iron@mail.ua
MFC after: 3 days
requires the return value of telldir() to equal the value passed to
seekdir(). The current seekdir code with SINGLEUSE enabled breaks
this case as each call to telldir() allocates a new cookie. Instead,
remove the SINGLEUSE code and change telldir() to look for an existing
cookie for the directory's current location rather than always creating
a new cookie.
CR: https://phabric.freebsd.org/D490
PR: 121656
Reviewed by: jilles
MFC after: 1 week
