The typical case was:
static __inline int
convert_ccl(FILE *fp, char * __restrict p, [...])
{
[...]
if (p == SUPPRESS_PTR) {
[...]
} else {
[...]
}
[...]
}
This qualifier says that the pointer is the only one at that time
pointing to the resource.
Here, clang considers that "p" will never match "SUPPRESS_PTR" and
optimize the if{} block out. This leads to segfaults in programs calling
vfscanf(3) and vfwscanf(3) with just the format string (no arguments
following it).
The following softwares were reported to abort with segmentation fault
and this patch fixes it:
o cmake
o smartd
o devel/ORBit2
dim@ opened an LLVM PR to discuss this clang optimization:
http://llvm.org/bugs/show_bug.cgi?id=12656
Tested by: bsam@
conversions. Both the specification and the documentation say the
width is interpreted as the max number of wide characters to read, but
the implementation was interpreting it as the number of bytes to convert.
(See also r105317.)
This change has security implications for any applications that depend
on the buggy behavior, but the impact in practice is probably nil.
Any such application would already be buggy on other platforms that
get the semantics right. Also, these conversions are rarely used;
%ls, %lc, and %l[ are more appropriate.
reading wide characters manually. With this change, they now use
fgetwc(). To make this work, we use an internal version of fgetwc()
with a few extensions: it takes an mbstate * because non-wide streams
don't have a built-in mbstate, and it indicates the number of bytes
read.
vfscanf() now resembles vfwscanf() more closely. Minor functional
improvements include working xlocale support in vfscanf(), setting the
stream error indicator on encoding errors, and proper handling of
shift-based encodings. (Actually, making shift-based encodings work
with non-wide streams is hopeless, but the implementation now matches
the broken specification.)
This tool changes the default buffering behaviour of standard
stdio streams.
It only works on dynamic binaries. To make it work for static
ones it would require cluttering stdio because there no single
entry point.
PR: 166660
Reviewed by: current@, jhb
Approved by: kib (mentor)
MFC after: 1 week
indicates the avaliability of FILE, to prevent possible reordering of
the writes as seen by other CPUs.
Reported by: Fengwei yin <yfw.bsd gmail com>
Reviewed by: jhb
MFC after: 1 week
by separate conversion functions. This will hopefully make bugs more
noticeable (I noticed several already) and provide opportunities to
reduce code duplication.
(i.e., the return value would overflow), set errno to EOVERFLOW
and return an error. This improves the chances that buggy
applications -- for instance, ones that pass in a negative integer
as the size due to a bogus calculation -- will fail in safe ways.
Returning an error in these situations is specified by POSIX, but
POSIX appears to have an off-by-one error that isn't duplicated in
this change.
Previously, some of these functions would silently cap the size at
INT_MAX+1, and others would exit with an error after writing more
than INT_MAX characters.
PR: 39256
MFC after: 2 weeks
true if the size is zero.
- Fix a claim that sprintf() is the same as snprintf() with an
infinite size. It's equivalent to snprintf() with a size of
INT_MAX + 1.
- Document the return values in the return values section.
- Document the possible errno value of EOVERFLOW.
MFC after: 2 weeks
infinite loop pretty much unconditionally. It's remarkable that the
patch that introduced the bug was never tested, but even more
remarkable that nobody noticed for over two years.
PR: 167039
MFC after: 3 days
load of _l suffixed versions of various standard library functions that use
the global locale, making them take an explicit locale parameter. Also
adds support for per-thread locales. This work was funded by the FreeBSD
Foundation.
Please test any code you have that uses the C standard locale functions!
Reviewed by: das (gdtoa changes)
Approved by: dim (mentor)
- If precision is 0, don't print period followed by no digits.
- If precision is 0 stop printing units as soon as possible
(eg. if we have three years and five days and precision is 0
print only 3y5d).
- If precision is not 0, print all units (eg. 3y0d0h0m0s.00).
MFC after: 2 weeks
the existing file descriptor. Instead, let dup2() atomically close the
old file descriptor when assigning the newly opened file to the same
descriptor. This closes a race in a multithreaded application where a
concurrent open() could allocate the existing file descriptor in between
the calls to close() and dup2().
PR: threads/79887
Submitted by: Dmitrij Tejblum tejblum of yandex-team.ru
Reviewed by: davidxu
MFC after: 1 week
bottom of the manpages and order them consistently.
GNU groff doesn't care about the ordering, and doesn't even mention
CAVEATS and SECURITY CONSIDERATIONS as common sections and where to put
them.
Found by: mdocml lint run
Reviewed by: ru
by *sprintf(), etc.
- Explicitly initialize _fl_mutex to PTHREAD_MUTEX_INITIALIZER for all FILE
objects. This is currently a nop on FreeBSD, but is import for other
platforms (or in the future) where PTHREAD_MUTEX_INITIALIZER is not simply
zero.
PR: threads/141198
Reported by: Jeremy Huddleston @ Apple
MFC after: 2 weeks
Prior to this commit, fread/fwrite calls with size * nmemb > SIZE_MAX
were handled by reading or writing (size_t)(size * nmemb) bytes; for
example, on 32-bit platforms, fread(ptr, 641, 6700417, f) would read 1
byte and indicate that the requested 6700417 blocks had been read.
This commit adds a check for such integer overflows, and treats them as
if an overly large request was passed to read/write; i.e., it sets errno
to EINVAL, sets the error indicator on the file, and returns a short
object count (0, to be specific).
The overflow check involves an integer division, so as a performance
optimization we check first to see if both size and nmemb are less than
2^16; if they are, no overflow is possible and we avoid the division.
We assume here that size_t is at least 32 bits; this appears to be true
on all platforms FreeBSD supports.
Although this commit fixes an integer overflow, it is not likely to have
any security implications, since any program which would be affected by
this bug fix is quite clearly already very confused.
Reviewed by: kib
MFC after: 1 month
and moving the default initialization of prec into the else clause.
The clang static analyzer erroneously thought that nsec can be used
uninitialized here; it was not actually possible, but better to make
the code clearer. (Clang can't know that sprintf() won't modify *pi
behind the scenes.)
uninitialized. Initialize it to a safe value so that there's no
chance of returning an error if stack garbage happens to be equal to
(size_t)-1 or (size_t)-2.
Found by: Clang static analyzer
MFC after: 7 days
- Tolerate applications that pass a NULL pointer for the buffer and
claim that the capacity of the buffer is nonzero.
- If an application passes in a non-NULL buffer pointer and claims the
buffer has zero capacity, we should free (well, realloc) it
anyway. It could have been obtained from malloc(0), so failing to
free it would be a small memory leak.
MFC After: 2 weeks
Reported by: naddy
PR: ports/138320
Right now nmemb is returned when size is 0. In newer versions of the
standards, it is explicitly required that fwrite() should return 0.
Submitted by: Christoph Mallon
Approved by: re (kib)
because it means getdelim() returns -1 for both error and EOF, and
never returns 0. However, this is what the original GNU implementation
does, and POSIX inherited the bug.
Reported by: marcus@
