When elf_memory is called we could get a slightly too small image
that doesn't contain a full ELF header (but does contain at least
the e_ident values). Require the full header before even validating
the rest of the ELF header fields.
https://sourceware.org/bugzilla/show_bug.cgi?id=27076
Signed-off-by: Mark Wielaard <mark@klomp.org>
Some years ago, in commit b1d0b0fc "libelf: Use int64_t for offsets in
libelf.h", we changed the public interface to use 64bit offsets/sizes.
This wasn't really a API change, before we relied on loff_t always
being 64bits on all platforms.
We didn't change the implementation to use the int64_t type though.
That was a little confusing, since the function definitions used a
different type, int64_t, from the function implementations, off_t.
Since we always build with _FILE_OFFSET_BITS=64 this should be fine.
But it was a bit sloppy and confusing.
Worse is that we got the translation of offset/sizes wrong in a
couple of places when translating to ELF types. In various places
we would use Elf32_Word or Elf64_Word. But both are 32bit (unsigned)
types! As is GElf_Word. Elf32_Off is 32bits and Elf64_Off is 64bits.
But we were not using those consistently.
This patch introduces comments for the usage of [G]Elf(32|64)Word in
libelf that are correct. And introduces Elf(32|64)_SizeWord in
elf32_updatenull.c where we want to make a difference between sizes
and offsets (the ELF variants are both unsigned, while int64_t/loff_t
is signed).
It also includes a new run-large-elf-file.sh test that creates a
large ELF files (one 64bit, little endian, rel and another big endian,
non-rel) and runs eu-strip, eu-elflint, eu-unstrip and eu-elfcmp.
Before this patch, that test case fails and creates corrupt ELF files.
The test is guarded by some checks that try to make sure there is
enough disk space and memory available on the machine. The test is
skipped otherwise.
Signed-off-by: Mark Wielaard <mark@klomp.org>
Remove (partially defined out) code and data structures dealing with
multiple ELF versions. There hasn't been a new ELF version in the
last 20 years. Simplify the code a bit by just assuming there will
only be one version (EV_CURRENT == 1).
Simplifies elf_version, gets rid of __libelf_version_initialized.
Removes one (or more) array (version) dimension from various tables
and accessor functions (__elf_xfctstom, shtype_map, __libelf_data_type,
__libelf_type_aligns and __libelf_type_sizes).
Signed-off-by: Mark Wielaard <mark@klomp.org>`
The ar_size is given as a fixed size decimal string, right padded with
spaces. Make sure we read it properly even if there is no terminating
space. Also sanity check len early if we can.
https://sourceware.org/bugzilla/show_bug.cgi?id=24085
Signed-off-by: Mark Wielaard <mark@klomp.org>
Use __attribute__ ((fallthrough)) to indicate switch case fall through
instead of a comment. This ensures that the fallthrough warning is not
triggered even if the file is pre-processed (hence stripping the
comments) before it is compiled.
The actual fallback implementation is hidden behind a FALLBACK macro in
case the compiler doesn't support it.
Finally, the -Wimplict-fallthrough warning was upgraded to only allow
the attribute to satisfy it; a comment alone is no longer sufficient.
Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
We won't use the e_shoff value in that case because we will set
elf->state.elf[64|32].scns.cnt to zero to indicate not to read
any section header data from the file.
Signed-off-by: Mark Wielaard <mark@klomp.org>
Add ELF_E_INVALID_ELF which is set when the ELF file data is bad.
This is different from ELF_E_INVALID_FILE which is set when the file
could not be read.
Signed-off-by: Mark Wielaard <mark@klomp.org>
There are various sanity checks that depend on knowing the file size
of the underlying ELF file which we only used when mmapping the ELF file.
Although we probably won't crash if we use pread to try to read from
the file, we still might return completely bogus data structures. This
could cause us to malloc insane amounts of memory.
Always try to get the maxsize when unknown in elf_begin.c (read_file).
https://bugzilla.redhat.com/show_bug.cgi?id=1388057
Signed-off-by: Mark Wielaard <mjw@redhat.com>
This change also creates a new header file libeu.h to provide the
prototypes for the function of libeu. That hides the definition of function
crc32, which can conflict with zlib, from libelf. It also prevents mistakes
to refer those functions from a component which doesn't link with libeu,
such as libelf.
Signed-off-by: Akihiko Odaki <akihiko.odaki.4i@stu.hosei.ac.jp>
* Move nested functions to file scope
in libelf/elf_begin.c and elf32_updatefile.c
to compile with clang.
Signed-off-by: Chih-Hung Hsieh <chh@google.com>
In get_shnum the check was whether the Elf(32|64)_Ehdr was correctly
aligned, but to access the Shdr directly we need to check whether the
address that points to the Elf(32|64)_Shdr structure is correctly aligned.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
There are various places in the code that check whether mmapped structures
are correctly aligned (or ALLOW_UNALIGNED is set). Some of these checks
are asserts. Like the one in elf(32|64)_getshdr. We should not get into
that part of the code if the shdr scn structure was cached in elf_begin
because it was mmapped in and properly aligned.
These asserts could trigger because in elf_begin.c file_read_elf ()
all alignment checks were combined. So even though only one of the ehdr,
shdr or phdr structures were not properly aligned all structures would be
copied. Also the phdr structure was not even read in elf_begin, so the
alignment check was unnecessary.
This patch splits the alignment checks and reading of ehdr and shdr
structures into separate code paths. It also drops the phdr alignment
checks in elf_begin. Those phdr checks are done in elf(32|64)_getphdr
already.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
Elf_Arhdr ar_size is loff_t, which is signed. Make sure it isn't negative.
When the parent start_offset is non-zero maxsize should include it to
compensate for ar offset.
Found with afl-fuzz.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
read_long_names terminates names at the first '/' found but then skips
one character without checking (it's supposed to be '\n'). Hence the
next name could start with any character including '/'. This leads to
a directory traversal vulnerability at the time the contents of the
archive is extracted.
The danger is mitigated by the fact that only one '/' is possible in a
resulting filename and only in the leading position. Hence only files
in the root directory can be written via this vuln and only when ar is
executed as root.
The fix for the vuln is to not skip any characters while looking
for '/'.
Signed-off-by: Alexander Cherepanov <cherepan@mccme.ru>
- The problem this is trying to solve can be seen for example thus:
$ eu-readelf -a /
eu-readelf: failed reading '/': (null)
With the fix we see a proper error number and get a reasonable error
message:
$ eu-readelf -a /
eu-readelf: failed reading '/': invalid file descriptor
Signed-off-by: Petr Machata <pmachata@redhat.com>
The --enable-mudflap configure build has been broken for 2 years without
anybody apparently noticing. GCC 4.9 removed mudflap support. Before
release we now run make distcheck with valgrind support. Removal of the
mudflap configure option simplifies the build a little.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
* Change name from "Red Hat elfutils" to "elfutils".
* Update license of standalone tools and test from GPLv2 to GPLv3+.
* Change license of libraries from GPLv2+exception to GPLv2/LGPLv3+.
* Add Developer Certificate of Origin based contributor policy.
top-level:
- COPYING: Upgraded from GPLv2 to GPLv3.
- CONTRIBUTING, COPYING-GPLv2, COPYING-LGPLv3: New files.
- NEWS: Added note about new contribution and license policy.
- Makefile.am: Updated to GPLv3, added new files to EXTRA_DIST.
- configure.ac: Update to GPLv3, changed AC_INIT name to 'elfutils'.
backends, lib, libasm, libcpu, libdw, libdwfl, libebl, libelf:
- All files updated to GPLv2/LGPLv3+. Except some very small files
(<5 lines) which didn't have any headers at all before, the linker
.maps files and the libcpu/defs files which only contain data and
libelf/elf.h which comes from glibc and is under LGPLv2+.
config:
- elfutils.spec.in: Add new License: headers and new %doc files.
- Update all license headers to GPLv2/LGPLv3+ for files used by libs.
src, tests:
- All files updated to GPLv3+. Except for the test bz2 data files, the
linker maps and script files and some very small files (<5 lines)
that don't have any headers.
Signed-off-by: Richard Fontana <rfontana@redhat.com>
Signed-off-by: Mark Wielaard <mjw@redhat.com>
2008-09-29 Roland McGrath <roland@redhat.com>
* segment.c (insert): Must realloc DWFL->lookup_module here too.
(dwfl_report_segment): Clear DWFL->lookup_module before insert calls.
lizhenlin