check_deferred_signal() returns twice, since handle_signal() emulates
the return from the normal signal handler by sigreturn(2)ing the
passed context. Second return is performed on the destroyed stack
frame, because __fillcontextx() has already returned. This causes
undefined and bad behaviour, usually the victim thread gets SIGSEGV.
Avoid nested frame and the need to return from it by doing direct call
to getcontext() in the check_deferred_signal() and using a new private
libc helper __fillcontextx2() to complement the context with the
extended CPU state if the deferred signal is still present.
The __fillcontextx() is now unused, but is kept to allow older
libthr.so to be used with the new libc.
Mark __fillcontextx() as returning twice [1].
Reported by: pgj
Pointy hat to: kib
Discussed with: dim
Tested by: pgj, dim
Suggested by: jilles [1]
MFC after: 1 week
If 'e' is used, the kernel must support the recently added pipe2() system
call.
The use of pipe2() with O_CLOEXEC also fixes race conditions between
concurrent popen() calls from different threads, even if the close-on-exec
flag on the fd of the returned FILE is later cleared (because popen() closes
all file descriptors from earlier popen() calls in the child process).
Therefore, this approach should be used in all cases when pipe2() can be
assumed present.
The old version of popen() rejects "re" and "we" but treats "r+e" like "r+".
The ability to clear a file descriptor's close-on-exec flag via
posix_spawn_file_actions_adddup2() is in fact proposed in Austin Group issue
#411.
MFC after: 1 week
As per POSIX.1-2008, posix_spawn_file_actions_add* return [EBADF] if a file
descriptor is negative, not [EINVAL]. The bug was only in the manual page;
the code is correct.
MFC after: 1 week
The functions utx_active_add(), utx_active_remove(), utx_lastlogin_add() and
utx_log_add() set errno to 0 if they are successful. This not only violates
POSIX if pututxline() is successful, but may also overwrite a valid error
with 0 if, for example, utx_lastlogin_add() fails while utx_log_add()
succeeds.
Reviewed by: ed
signal.
- Fix the old ksem implementation for POSIX semaphores to not restart
sem_wait() or sem_timedwait() if interrupted by a signal.
MFC after: 1 week
Words in shell script are separated by spaces or tabs independent of the
value of IFS. The value of IFS is only relevant for the result of
substitutions. Therefore, there should be a space between 'wordexp' and the
words to be expanded, not an IFS character.
Paranoia might dictate that the shell ignore IFS from the environment (even
though our sh currently uses it), so do not depend on it in the new test
case.
multibyte support[0] and the new functions strenvisx and strsenvisx.
Add MLINKS for vis(3) functions add by this and the initial import from
NetBSD[1].
PR: bin/166364, bin/175418
Submitted by: "J.R. Oldroyd" <fbsd@opal.com>[0]
stefanf[1]
Obtained from: NetBSD
MFC after: 2 weeks
system call, which has a nice property - it never fails, so it is a bit
easier to use. If there is no support for capability mode in the kernel
the function will return false (not in a sandbox). If the kernel is compiled
with the support for capability mode, the function will return true or false
depending if the calling process is in the capability mode sandbox or not
respectively.
Sponsored by: The FreeBSD Foundation
* Reopen the directory using openat(fd, ".", ...) instead of opening the
pathname again. This fixes a race condition where the meaning of the
pathname changes and allows a reopen with fdopendir().
* Always reopen the directory for union stacks, not only when DTF_REWIND
is passed. Applications should be able to fchdir(dirfd(dir)) and
*at(dirfd(dir), ...). DTF_REWIND now does nothing.
There are uncommon cases where fts_safe_changedir() may be called with a
non-NULL name that is not "..". Do not block or worse if an attacker put (a
(symlink to) a fifo or device where a directory used to be.
MFC after: 1 week
path longer than this.
- Fix an unreached case of check against sizeof buf, which in turn leads
to an off-by-one nul byte write on the stack. The original condition
can never be satisfied because the passed boundary is the maximum value
that can be returned, so code was harmless.
MFC after: 1 month
NetBSD's. This output size limited versions of vis and unvis functions
as well as a set of vis variants that allow arbitrary characters to be
specified for encoding.
Finally, MIME Quoted-Printable encoding as described in RFC 2045 is
supported.
The changes were derived from what has been committed to NetBSD, with
modifications. These are:
1. Preserve the existsing GLOB_LIMIT behaviour by including the number
of matches to the set of parameters to limit.
2. Change some of the limits to avoid impacting normal use cases:
GLOB_LIMIT_STRING - change from 65536 to ARG_MAX so that glob(3)
can still provide a full command line of expanded names.
GLOB_LIMIT_STAT - change from 128 to 1024 for no other reason than
that 128 feels too low (it's not a limit that impacts the
behaviour of the test program listed in CVE-2010-2632).
GLOB_LIMIT_PATH - change from 1024 to 65536 so that glob(3) can
still provide a fill command line of expanded names.
3. Protect against buffer overruns when we hit the GLOB_LIMIT_STAT or
GLOB_LIMIT_READDIR limits. We append SEP and EOS to pathend in
those cases. Return GLOB_ABORTED instead of GLOB_NOSPACE when we
would otherwise overrun the buffer.
This change also modifies the existing behaviour of glob(3) in case
GLOB_LIMIT is specifies by limiting the *new* matches and not all
matches. This is an important distinction when GLOB_APPEND is set or
when the caller uses a non-zero gl_offs. Previously pre-existing
matches or the value of gl_offs would be counted in the number of
matches even though the man page states that glob(3) would return
GLOB_NOSPACE when gl_matchc or more matches were found.
The limits that cannot be circumvented are GLOB_LIMIT_STRING and
GLOB_LIMIT_PATH all others can be crossed by simply calling glob(3)
again and with GLOB_APPEND set.
The entire description above applies only when GLOB_LIMIT has been
specified of course. No limits apply when this flag isn't set!
Obtained from: Juniper Networks, Inc
equivalent to malloc(size). This eliminates the conditional expression
used for calling either realloc() or malloc() when realloc() will do
all the time.
free and clear the gl_pathv pointer in the glob_t structure. Such
breaks the invariant of the glob_t structure, as stated in the comment
right in front of the globextend() function. If gl_pathv was non-NULL,
then gl_pathc was > 0. Making gl_pathv a NULL pointer without also
setting gl_pathc to 0 is wrong.
Since we otherwise don't free the memory associated with a glob_t in
error cases, it's unlikely that this change will cause a memory leak
that wasn't already there to begin with. Callers of glob(3) must
call globfree(3) irrespective of whether glob(3) returned an error
or not.
libc.a and libc_p.a. In addition, define isnan in libm.a and libm_p.a,
but not in libm.so.
This makes it possible to statically link executables using both isnan
and isnanf with libc and libm.
Tested by: kargl
MFC after: 1 week
This adds two features:
* uid_from_user() and gid_from_group() as the reverse of user_from_uid()
and groups_from_gid().
* pwcache_userdb() and pwcache_groupdb() which allow alternative lookup
functions to be used. For example lookups from passwd and group
databases in a non-standard location.
This fixes a race condition where another thread may fork() before CLOEXEC
is set, unintentionally passing the descriptor to the child process.
This commit only adds O_CLOEXEC flags to open() or openat() calls where no
fcntl(fd, F_SETFD, FD_CLOEXEC) follows. The separate fcntl() call still
leaves a race window so it should be fixed later.
Because fts keeps internal file descriptors open across calls, making such
descriptors close-on-exec helps not only multi-threaded applications but
also single-threaded applications.
In particular, this prevents passing a temporary file descriptor for saving
the current directory to processes created via find -exec.
