The API docs gave an impression that such checks are done
but they actually weren't done. In practice it made little
difference since the calling code has a bug if these are NULL.
Thanks to Jia Tan for the original patch that checked for
block->filters == NULL.
If someone sets up Clang to define __GNUC__ to 10 or greater
then symvers broke. __has_attribute is supported by such GCC
and Clang versions that don't support __symver__ so this should
be much better and simpler way to detect if __symver__ is
actually supported.
Thanks to Tomasz Gajc for the bug report.
It not only makes no sense to put symbol versions into a static library
but it can also cause breakage.
By default Libtool #defines PIC if building a shared library and
doesn't define it for static libraries. This is documented in the
Libtool manual. It can be overriden using --with-pic or --without-pic.
configure.ac detects if --with-pic or --without-pic is used and then
gives an error if neither --disable-shared nor --disable-static was
used at the same time. Thus, in normal situations it works to build
both shared and static library at the same time on GNU/Linux,
only --with-pic or --without-pic requires that only one type of
library is built.
Thanks to John Paul Adrian Glaubitz from Debian for reporting
the problem that occurred on ia64:
https://www.mail-archive.com/xz-devel@tukaani.org/msg00610.html
This time it can happen when lzma_stream_encoder_mt() is used
to reinitialize an existing multi-threaded Stream encoder
and one of 1-4 tiny allocations in lzma_filters_copy() fail.
It's very similar to the previous bug
10430fbf38, happening with
an array of lzma_filter structures whose old options are freed
but the replacement never arrives due to a memory allocation
failure in lzma_filters_copy().
The documentation mentions that lzma_block_encoder() supports
LZMA_SYNC_FLUSH but it was never added to supported_actions[]
in the internal structure. Because of this, LZMA_SYNC_FLUSH could
not be used with the Block encoder unless it was the next coder
after something like stream_encoder() or stream_encoder_mt().
The bug was in the single-threaded .xz Stream encoder
in the code that is used for both re-initialization and for
lzma_filters_update(). To trigger it, an application had
to either re-initialize an existing encoder instance with
lzma_stream_encoder() or use lzma_filters_update(), and
then one of the 1-4 tiny allocations in lzma_filters_copy()
(called from stream_encoder_update()) must fail. An error
was correctly reported but the encoder state was corrupted.
This is related to the recent fix in
f8ee61e74e which is good but
it wasn't enough to fix the main problem in stream_encoder.c.
The encoder doesn't support dictionary sizes larger than 1536 MiB.
This is validated, for example, when calculating the memory usage
via lzma_raw_encoder_memusage(). It is also enforced by the LZ
part of the encoder initialization. However, LZMA encoder with
LZMA_MODE_NORMAL did an unsafe calculation with dict_size before
such validation and that results in an infinite loop if dict_size
was 2 << 30 or greater.
__SSE2__ is the correct macro for SSE2 support with GCC, Clang,
and ICC. __SSE2_MATH__ means doing floating point math with SSE2
instead of 387. Often the latter macro is defined if the first
one is but it was still a bug.
In practice this means making the scripts work when
the input files have an unsupported check type which
isn't a problem in practice unless support for
some check types has been disabled at build time.
"xz -v < regular_file > out.xz" doesn't display the percentage
and estimated remaining time because it doesn't even try to
check the input file size when input is read from stdin.
This could be improved but for now there's just a comment
to remind about it.
It worked for one input file since the counters are zero when
xz starts but they weren't reset when starting a new file in
passthru mode. For example, if files A, B, and C are one byte each,
then "xz -dcvf A B C" would show file sizes as 1, 2, and 3 bytes
instead of 1, 1, and 1 byte.
Don't call InitOnceComplete() if initialization was already done.
So far mythread_once() has been needed only when building
with --enable-small. windows/build.bash does this together
with --disable-threads so the Vista-specific mythread_once()
is never needed by those builds. VS project files or
CMake-builds don't support HAVE_SMALL builds at all.
Example:
$ xz -dc --single-stream good-0-empty.xz
xz: good-0-empty.xz: Internal error (bug)
The code, that is tries to catch some input file issues early,
didn't anticipate LZMA_STREAM_END which is possible in that
code only when --single-stream is used.
Now files with unsupported check will make xz display
a warning, set the exit status to 2 (unless --no-warn is used),
and then decompress the file normally. This is how it was
supposed to work since the beginning but this was broken by
the commit 231c3c7098, that is,
a little before 5.0.0 was released. The buggy behavior displayed
a message, set exit status 1 (error), and xz didn't attempt to
to decompress the file.
This doesn't matter today except for special builds that disable
CRC64 or SHA-256 at build time (but such builds should be used
in special situations only). The bug matters if new check type
is added in the future and an old xz version is used to decompress
such a file; however, it's likely that such files would use a new
filter too and an old xz wouldn't be able to decompress the file
anyway.
The first hunk in the commit is the actual fix. The second hunk
is a cleanup since LZMA_TELL_ANY_CHECK isn't used in xz.
There is a test file for unsupported check type but it wasn't
used by test_files.sh, perhaps due to different behavior between
xz and the simpler xzdec.
Treating it as a warning (message + exit status 2) matches gzip
and it seems more logical as at that point the output file has
already been successfully closed. When it's a warning it is
possible to suppress it with --no-warn.
On OpenBSD the number of cores online is often less
than what HW_NCPU would return because OpenBSD disables
simultaneous multi-threading (SMT) by default.
Thanks to Christian Weisgerber.
The documentation states LZMA_PROG_ERROR can be returned from
lzma_index_cat. Previously, lzma_index_cat could not return
LZMA_PROG_ERROR. Now, the validation is similar to
lzma_index_append, which does a NULL check on the index
parameter.
The check type of the last Stream in dest was never copied to
dest->checks (the code tried to copy it but it was done too late).
This meant that the value returned by lzma_index_checks() would
only include the check type of the last Stream when multiple
lzma_indexes had been concatenated.
In xz --list this meant that the summary would only list the
check type of the last Stream, so in this sense this was only
a visual bug. However, it's possible that some applications
use this information for purposes other than merely showing
it to the users in an informational message. I'm not aware of
such applications though and it's quite possible that such
applications don't exist.
Regular streamed decompression in xz or any other application
doesn't use lzma_index_cat() and so this bug cannot affect them.
If lzma_code() returns LZMA_MEMLIMIT_ERROR it is now possible
to use lzma_memlimit_set() to increase the limit and continue
decoding. This was supposed to work from the beginning but
there was a bug. With other decoders (.lzma or threaded .xz)
this already worked correctly.
Running the current xzgrep on Slackware 10.1 with GNU bash 3.00.15:
xzgrep: line 231: syntax error near unexpected token `;;'
On SCO OpenServer 5.0.7 with Korn Shell 93r:
syntax error at line 231 : `;;' unexpected
Turns out that some old shells don't like apostrophes (') inside
command substitutions. For example, the following fails:
x=$(echo foo
# asdf'zxcv
echo bar)
printf '%s\n' "$x"
The problem was introduced by commits
69d1b3fc29 (2022-03-29),
bd7b290f3f (2022-07-18), and
a648978b20 (2022-07-19).
5.2.6 is the only stable release that included
this problem.
Thanks to Kevin R. Bulgrien for reporting the problem
on SCO OpenServer 5.0.7 and for providing the fix.
lzma_stream_encoder() and lzma_stream_encoder_mt() always assumed
this. Before this patch, failing lzma_filters_copy() could result
in free(invalid_pointer) or invalid memory reads in stream_encoder.c
or stream_encoder_mt.c.
To trigger this, allocating memory for a filter options structure
has to fail. These are tiny allocations so in practice they very
rarely fail.
Certain badness in the filter chain array could also make
lzma_filters_copy() fail but both stream_encoder.c and
stream_encoder_mt.c validate the filter chain before
trying to copy it, so the crash cannot occur this way.
The documentation in src/liblzma/api/lzma/index.h suggests that
both the unpadded (compressed) size and the uncompressed size
are checked for overflow, but only the unpadded size was checked.
The uncompressed check is done first since that is more likely to
occur than the unpadded or index field size overflows.
RHEL/CentOS 7 shipped with 5.1.2alpha, including the threaded
encoder that is behind #ifdef LZMA_UNSTABLE in the API headers.
In 5.1.2alpha these symbols are under XZ_5.1.2alpha in liblzma.map.
API/ABI compatibility tracking isn't done between development
releases so newer releases didn't have XZ_5.1.2alpha anymore.
Later RHEL/CentOS 7 updated xz to 5.2.2 but they wanted to keep
the exported symbols compatible with 5.1.2alpha. After checking
the ABI changes it turned out that >= 5.2.0 ABI is backward
compatible with the threaded encoder functions from 5.1.2alpha
(but not vice versa as fixes and extensions to these functions
were made between 5.1.2alpha and 5.2.0).
In RHEL/CentOS 7, XZ Utils 5.2.2 was patched with
xz-5.2.2-compat-libs.patch to modify liblzma.map:
- XZ_5.1.2alpha was added with lzma_stream_encoder_mt and
lzma_stream_encoder_mt_memusage. This matched XZ Utils 5.1.2alpha.
- XZ_5.2 was replaced with XZ_5.2.2. It is clear that this was
an error; the intention was to keep using XZ_5.2 (XZ_5.2.2
has never been used in XZ Utils). So XZ_5.2.2 lists all
symbols that were listed under XZ_5.2 before the patch.
lzma_stream_encoder_mt and _mt_memusage are included too so
they are listed both here and under XZ_5.1.2alpha.
The patch didn't add any __asm__(".symver ...") lines to the .c
files. Thus the resulting liblzma.so exports the threaded encoder
functions under XZ_5.1.2alpha only. Listing the two functions
also under XZ_5.2.2 in liblzma.map has no effect without
matching .symver lines.
The lack of XZ_5.2 in RHEL/CentOS 7 means that binaries linked
against unpatched XZ Utils 5.2.x won't run on RHEL/CentOS 7.
This is unfortunate but this alone isn't too bad as the problem
is contained within RHEL/CentOS 7 and doesn't affect users
of other distributions. It could also be fixed internally in
RHEL/CentOS 7.
The second problem is more serious: In XZ Utils 5.2.2 the API
headers don't have #ifdef LZMA_UNSTABLE for obvious reasons.
This is true in RHEL/CentOS 7 version too. Thus now programs
using new APIs can be compiled without an extra #define. However,
the programs end up depending on symbol version XZ_5.1.2alpha
(and possibly also XZ_5.2.2) instead of XZ_5.2 as they would
with an unpatched XZ Utils 5.2.2. This means that such binaries
won't run on other distributions shipping XZ Utils >= 5.2.0 as
they don't provide XZ_5.1.2alpha or XZ_5.2.2; they only provide
XZ_5.2 (and XZ_5.0). (This includes RHEL/CentOS 8 as the patch
luckily isn't included there anymore with XZ Utils 5.2.4.)
Binaries built by RHEL/CentOS 7 users get distributed and then
people wonder why they don't run on some other distribution.
Seems that people have found out about the patch and been copying
it to some build scripts, seemingly curing the symptoms but
actually spreading the illness further and outside RHEL/CentOS 7.
The ill patch seems to be from late 2016 (RHEL 7.3) and in 2017 it
had spread at least to EasyBuild. I heard about the events only
recently. :-(
This commit splits liblzma.map into two versions: one for
GNU/Linux and another for other OSes that can use symbol versioning
(FreeBSD, Solaris, maybe others). The Linux-specific file and the
matching additions to .c files add full compatibility with binaries
that have been built against a RHEL/CentOS-patched liblzma. Builds
for OSes other than GNU/Linux won't get the vaccine as they should
be immune to the problem (I really hope that no build script uses
the RHEL/CentOS 7 patch outside GNU/Linux).
The RHEL/CentOS compatibility symbols XZ_5.1.2alpha and XZ_5.2.2
are intentionally put *after* XZ_5.2 in liblzma_linux.map. This way
if one forgets to #define HAVE_SYMBOL_VERSIONS_LINUX when building,
the resulting liblzma.so.5 will have lzma_stream_encoder_mt@@XZ_5.2
since XZ_5.2 {...} is the first one that lists that function.
Without HAVE_SYMBOL_VERSIONS_LINUX @XZ_5.1.2alpha and @XZ_5.2.2
will be missing but that's still a minor problem compared to
only having lzma_stream_encoder_mt@@XZ_5.1.2alpha!
The "local: *;" line was moved to XZ_5.0 so that it doesn't need
to be moved around. It doesn't matter where it is put.
Having two similar liblzma_*.map files is a bit silly as it is,
at least for now, easily possible to generate the generic one
from the Linux-specific file. But that adds extra steps and
increases the risk of mistakes when supporting more than one
build system. So I rather maintain two files in parallel and let
validate_map.sh check that they are in sync when "make mydist"
is run.
This adds .symver lines for lzma_stream_encoder_mt@XZ_5.2.2 and
lzma_stream_encoder_mt_memusage@XZ_5.2.2 even though these
weren't exported by RHEL/CentOS 7 (only @@XZ_5.1.2alpha was
for these two). I added these anyway because someone might
misunderstand the RHEL/CentOS 7 patch and think that @XZ_5.2.2
(@@XZ_5.2.2) versions were exported too.
At glance one could suggest using __typeof__ to copy the function
prototypes when making aliases. However, this doesn't work trivially
because __typeof__ won't copy attributes (lzma_nothrow, lzma_pure)
and it won't change symbol visibility from hidden to default (done
by LZMA_API()). Attributes could be copied with __copy__ attribute
but that needs GCC 9 and a fallback method would be needed anyway.
This uses __symver__ attribute with GCC >= 10 and
__asm__(".symver ...") with everything else. The attribute method
is required for LTO (-flto) support with GCC. Using -flto with
GCC older than 10 is now broken on GNU/Linux and will not be fixed
(can silently result in a broken liblzma build that has dangerously
incorrect symbol versions). LTO builds with Clang seem to work
with the traditional __asm__(".symver ...") method.
Thanks to Boud Roukema for reporting the problem and discussing
the details and testing the fix.
Previously this required using --force but that has other
effects too which might be undesirable. Changing the behavior
of --keep has a small risk of breaking existing scripts but
since this is a fairly special corner case I expect the
likehood of breakage to be low enough.
I think the new behavior is more logical. The only reason for
the old behavior was to be consistent with gzip and bzip2.
Thanks to Vincent Lefevre and Sebastian Andrzej Siewior.
xzgrep wouldn't exit on SIGPIPE or SIGQUIT when it clearly
should have. It's quite possible that it's not perfect still
but at least it's much better.
If multiple exit statuses compete, now it tries to pick
the largest of value.
Some comments were added.
The exit status handling of signals is still broken if the shell
uses values larger than 255 in $? to indicate that a process
died due to a signal ***and*** their "exit" command doesn't take
this into account. This seems to work well with the ksh and yash
versions I tried. However, there is a report in gzip/zgrep that
OpenSolaris 5.11 (not 5.10) has a problem with "exit" truncating
the argument to 8 bits:
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22900#25
Such a bug would break xzgrep but I didn't add a workaround
at least for now. 5.11 is old and I don't know if the problem
exists in modern descendants, or if the problem exists in other
ksh implementations in use.
I don't know if this can make a difference in the real world
but it looked kind of suspicious (what happens with sed
implementations that cannot process very long lines?).
At least this commit shouldn't make it worse.
It avoids the use of sed for prefixing filenames to output lines.
Using sed for that is slower and prone to security bugs so now
the sed method is only used as a fallback.
This also fixes an actual bug: When grepping a binary file,
GNU grep nowadays prints its diagnostics to stderr instead of
stdout and thus the sed-method for prefixing the filename doesn't
work. So with this commit grepping binary files gives reasonable
output with GNU grep now.
This was inspired by zgrep but the implementation is different.
Also replace one use of expr with printf.
The rationale for LC_ALL=C was already mentioned in
69d1b3fc29 that fixed a security
issue. However, unrelated uses weren't changed in that commit yet.
POSIX says that with sed and such tools one should use LC_ALL=C
to ensure predictable behavior when strings contain byte sequences
that aren't valid multibyte characters in the current locale. See
under "Application usage" in here:
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/sed.html
With GNU sed invalid multibyte strings would work without this;
it's documented in its Texinfo manual. Some other implementations
aren't so forgiving.
Fix handling of "xzgrep -25 foo" (in GNU grep "grep -25 foo" is
an alias for "grep -C25 foo"). xzgrep would treat "foo" as filename
instead of as a pattern. This bug was fixed in zgrep in gzip in 2012.
Add -E, -F, -G, and -P to the "no argument required" list.
Add -X to "argument required" list. It is an
intentionally-undocumented GNU grep option so this isn't
an important option for xzgrep but it seems that other grep
implementations (well, those that I checked) don't support -X
so I hope this change is an improvement still.
grep -d (grep --directories=ACTION) requires an argument. In
contrast to zgrep, I kept -d in the "no argument required" list
because it's not supported in xzgrep (or zgrep). This way
"xzgrep -d" gives an error about option being unsupported instead
of telling that it requires an argument. Both zgrep and xzgrep
tell that it's unsupported if an argument is specified.
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