The argument to vli_ceil4() should always guarantee the return value
is also a valid lzma_vli. Thus the highest three valid lzma_vli values
are invalid arguments. All uses of the function ensure this so the
assert is updated to match this.
This was not a security bug since there was no path to overflow
UINT64_MAX in lzma_index_append() or when it calls index_file_size().
The bug was discovered by a failing assert() in vli_ceil4() when called
from index_file_size() when unpadded_sum (the sum of the compressed size
of current Stream and the unpadded_size parameter) exceeds LZMA_VLI_MAX.
Previously, the unpadded_size parameter was checked to be not greater
than UNPADDED_SIZE_MAX, but no check was done once compressed_base was
added.
This could not have caused an integer overflow in index_file_size() when
called by lzma_index_append(). The calculation for file_size breaks down
into the sum of:
- Compressed base from all previous Streams
- 2 * LZMA_STREAM_HEADER_SIZE (size of the current Streams header and
footer)
- stream_padding (can be set by lzma_index_stream_padding())
- Compressed base from the current Stream
- Unpadded size (parameter to lzma_index_append())
The sum of everything except for Unpadded size must be less than
LZMA_VLI_MAX. This is guarenteed by overflow checks in the functions
that can set these values including lzma_index_stream_padding(),
lzma_index_append(), and lzma_index_cat(). The maximum value for
Unpadded size is enforced by lzma_index_append() to be less than or
equal UNPADDED_SIZE_MAX. Thus, the sum cannot exceed UINT64_MAX since
LZMA_VLI_MAX is half of UINT64_MAX.
Thanks to Joona Kannisto for reporting this.
When the compiler supports __attribute__((__constructor__))
mythread_once() is never used, even with --enable-small. A configuration
with win95 threads and --enable-small will compile and be thread safe so
it can be allowed.
This isn't a very common configuration since MSVC does not support
__attribute__((__constructor__)), but MINGW32 and CLANG32 environments
for MSYS2 can use win95 threads and have
__attribute__((__constructor__)) support.
The "once_" variable was accidentally referred to as just "once". This
prevented building with Vista threads when
HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR was not defined.
groff defaults to SGR escapes. Using -P-c passes -c to grotty
which restores the old behavior. Perhaps there is a better way to
get pure plain text output but this works for now.
signal.h in WASI SDK doesn't currently provide sigprocmask()
or sigset_t. liblzma doesn't need them so this change makes
liblzma and xzdec build against WASI SDK. xz doesn't build yet
and the tests don't either as tuktest needs setjmp() which
isn't (yet?) implemented in WASI SDK.
Closes: https://github.com/tukaani-project/xz/pull/57
See also: https://github.com/tukaani-project/xz/pull/56
(The original commit was edited a little by Lasse Collin.)
The CMake build will try to create broken symlinks on Unix and Unix-like
platforms. Cygwin and MSYS2 are Unix-like, but may not be able to create
broken symlinks. The value of the CYGWIN or MSYS environment variables
determine if broken symlinks are valid.
The default for MSYS2 does not allow for broken symlinks, so the CMake
build has been broken for MSYS2 since commit
80a1a8bb83.
To workaround Automake lacking Windows resource compiler support, an
empty source file is compiled to overwrite the resource files for static
library builds. Translation units without an external declaration are
not allowed by the C standard and result in a warning when used with
-Wempty-translation-unit (Clang) or -pedantic (GCC).
Reword "options required" to "options read". The previous wording
may have suggested that the options listed were all required when
the filters are used for encoding or decoding. Now it should be
more clear that the options listed are the ones relevant for
encoding or decoding.
In lzma_memcmplen(), the <intrin.h> header file is only included if
_MSC_VER and _M_X64 are both defined but _BitScanForward64() was
previously used if _M_X64 was defined. GCC for MSYS2 defines _M_X64 but
not _MSC_VER so _BitScanForward64() was used without including
<intrin.h>.
Now, lzma_memcmplen() will use __builtin_ctzll() for MSYS2 GCC builds as
expected.
The new Tests section describes basic information about the tests, how
to run them, and important details when cross compiling. We have had a
few questions about how to compile the tests without running them, so
hopefully this information will help others with the same question in the
future.
Fixes: https://github.com/tukaani-project/xz/issues/54
