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* libelf: Always update e_version and e_shentsize in elf_update.Mark Wielaard2015-09-292-5/+13
| | | | | | | | | | | When e_version is EV_NONE we should set it to EV_CURRENT like we do for the EI_VERSION and like we set EI_DATA to the correct byte order when set to ELFDATANONE. Likewise we should always set e_shentsize like we do for e_phentsize, not just when ELF_F_LAYOUT isn't set. Add a new elfshphehdr testcase to check the above. Signed-off-by: Mark Wielaard <[email protected]>
* Properly mark all internal function definitions.Mark Wielaard2015-09-238-0/+23
| | | | | | | | | | | | | | | | | Since we banned old style function definitions GCC is able to diagnose function definitions that don't match the function declaration: elf32_getehdr.c:78: error: conflicting types for ‘__elf64_getehdr_wrlock’ libelfP.h:498: note: previous declaration of ‘__elf64_getehdr_wrlock’ This happens on i386 because there internal functions are marked with: # define internal_function __attribute__ ((regparm (3), stdcall)) Make sure all internal function declarations and definitions are marked with internal_function. Signed-off-by: Mark Wielaard <[email protected]>
* Remove old-style function definitions.Mark Wielaard2015-09-2386-398/+189
| | | | | | | We already require -std=gnu99 and old-style function definitions might hide some compiler warnings. Signed-off-by: Mark Wielaard <[email protected]>
* Update dl-hash.h from glibc.Mark Wielaard2015-09-232-41/+38
| | | | | | | | | | Our dl-hash.h implementation originally came from, or was written at the same time as, the glibc implementation. At some point (around 9 years ago) they diverged and the elfutils version got an updated copyright header. The glibc version saw various updates/optimizations. Just treat the file like we do for elf.h and copy it whenever the glibc version is updated. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Don't leak memory on failure paths in elf_updatefile.Mark Wielaard2015-06-192-12/+22
| | | | | | | When something goes wrong during the update make sure to always free any temporary allocated memory (shdr_data and/or scns). Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Check symbol section header exists before use in nlist.Mark Wielaard2015-06-192-2/+10
| | | | Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Always call ftruncate before posix_fallocate to set the right size.Mark Wielaard2015-06-192-2/+10
| | | | | | | | | | | | | | | When elf_update.c (write_file) doesn't know the current maximum file length it might have to reduce the file size. posix_fallocate can only extend the file. So always call ftruncate before that to set the file size and making sure the backing store is fully there. Add test cases for checking strip in place (eu-strip without -o) actually reduces the file size. But only for non-ET_REL files. We might not be able to strip ET_REL files (except when they are kernel modules) because they might contain "dangling" symbol table entries. https://bugzilla.redhat.com/show_bug.cgi?id=1232206 Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Make sure elf_getdata_rawchunk returns aligned data.Mark Wielaard2015-06-093-3/+34
| | | | | | | | | | elf_getdata_rawchunk might return an unaligned buffer for the requested ELF data type. Make sure the data is also correctly aligned when using an mmapped file. Also add some missing alignments for ELF data types for __libelf_type_align (the missing types could also make elf_getdata to return unaligned data). Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Make sure conversion functions work on aligned data for type.Mark Wielaard2015-06-092-2/+29
| | | | | | | | | | | The gelf_xlate conversion functions work on properly aligned ELF data types. If elf_get data needs to do conversion and ! ALLOW_UNALIGNED and the rawdata_base isn't aligned properly for the section type, then provide an aligned copy of the data. Found with --enable-sanitize-undefined in run-test-archive64.sh on x86_64. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Check e_shoff alignment before direct access of Elf(32|64)_Shdr.Mark Wielaard2015-06-082-4/+9
| | | | | | | | 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 <[email protected]>
* libelf: Split checks for ehdr and shdr, drop phdr check in file_read_elf.Mark Wielaard2015-06-082-65/+80
| | | | | | | | | | | | | | | | | | | | | 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 <[email protected]>
* libelf: Fix possible unbounded stack usage in load_shdr_wrlock.Mark Wielaard2015-06-052-4/+19
| | | | | | | When a copy needs to be made of the shdrs, allocate with malloc and free after conversion instead of calling alloca. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Fix possible unbounded stack usage in getphdr_wrlock.Mark Wielaard2015-06-052-4/+19
| | | | | | | When a copy needs to be made of the phdrs, allocate with malloc and free after conversion instead of calling alloca. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Fix unbounded stack usage in elf_getarsym for !ALLOW_UNALIGNED case.Mark Wielaard2015-06-052-1/+14
| | | | | | | The number of entries in the index can be large, don't use alloca to read in temporary data, use malloc (which is freed after out). Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Don't call memmove with possible NULL buffer.Mark Wielaard2015-06-052-2/+7
| | | | | | When size is zero the buffer src and dest buffers might be NULL. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Don't call mempcpy with possible NULL d_buf.Mark Wielaard2015-06-052-1/+6
| | | | | | | When d_size is zero d_buf might be NULL. last_position doesn't need to be updated in that case. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Fix possible unbounded stack usage in updatefile.Mark Wielaard2015-05-272-3/+26
| | | | | | | Allocate shdr_data and scns with malloc, not alloca. Free after writing section headers. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Fix possible unbounded stack usage in updatemmap.Mark Wielaard2015-05-272-8/+28
| | | | | | | Allocate temporary shdr storage with malloc, not alloca. Free after writing section headers. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Fix possible unbounded stack usage in elf_getarsym.Mark Wielaard2015-05-272-2/+17
| | | | | | | The number of entries in the index can be large, don't use alloca to read in temporary data, use malloc (and free after out). Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Use posix_fallocate instead of ftruncate to extend ELF file.Mark Wielaard2015-05-272-3/+18
| | | | | | | | | | | | | | | | | | | This fixes an obscure SIGBUS error when using ELF_C_WRITE_MMAP on an ELF file that needs extending when the underlying file system is (nearly) full. Use posix_fallocate to make sure the file content is really there. Using ftruncate might mean the file is extended, but space isn't allocated yet. This might cause a SIGBUS once we write into the mmapped space and the disk is full. Using fallocate might fail on some file systems. posix_fallocate is required to extend the file and allocate enough space even if the underlying filesystem would normally return EOPNOTSUPP or the kernel doesn't implement the fallocate syscall. Also posix_fallocate has been in glibc since 2.1.94, while support for fallocate was only added in 2.10 and kernel 2.6.23. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: If e_phnum is zero then set e_phoff also to zero.Mark Wielaard2015-05-182-0/+13
| | | | | | | | | | If phnum is zero make sure e_phoff is also zero and not some random value. That would cause trouble in update_file. This could happen when ELF_F_LAYOUT is set and the user copied over a ehdr from a bogus ELF file where the phdrs are unreadable. In that case trying to write out the new ELF image would crash trying to follow the bogus e_phdr value. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: More checking of valid sh_addralign values.Mark Wielaard2015-05-183-0/+26
| | | | | | | | | | | | | | | | | | | | There were two issues with bogus sh_addralign values. First we would only check the individual Elf_Data d_align values were powerof2. But not the actual shdr addralign value. This would cause an issue if the shdr addralign was bigger than all of the individual d_align values. Then we could write out a bogus (! powerof2) shdr addralign value for the sections. Secondly when reading in the Elf_Data we would set the d_align value to the value of the shdr addralign value. But we would not check it was valid at all. In practice there are ELF files with incorrect sh_addralign values (they are a powerof2, but aren't aligned to the ELF image offset). We would try to fix that up in elf_update by adding extra padding. But this could bloat the ELF image a lot for large alignment values. So for too large alignments that are bigger than the offset in the ELF file clamp them to the offset value. This could lead us to reject to write out the data again when the offset was not a powerof2. But this will only happen for aligment values bigger than 64. Which are uncommon in practice. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Make sure shdrs are valid before storing extended phnum in newphdr.Mark Wielaard2015-05-182-1/+17
| | | | | | | | | Creating phdr with more than PN_XNUM phnum requires a valid section zero shdr to store the extended value. Make sure the shdrs are valid. Also fix the error when count was too big to store by setting ELF_E_INVALID_INDEX before failing. Signed-off-by: Mark Wielaard <[email protected]>
* Always call gelf_fsize with EV_CURRENT as argument.Mark Wielaard2015-05-132-1/+5
| | | | | | | | | | Don't trust the elf version given by the file. It could be completely bogus. In which case gelf_fsize just returns zero. Which could cause divide by zero errors. https://bugzilla.redhat.com/show_bug.cgi?id=1170810#c34 Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Make sure version xlate dest buffer is fully defined.Mark Wielaard2015-05-062-1/+16
| | | | | | | | | | | | | | https://bugzilla.redhat.com/show_bug.cgi?id=1170810#c16 contains an example of usage of undefined memory when version section data needs to be translated, but the version xlate functions detect they cannot fully transform the section data. To make sure the dest buffer data is completely defined this patch makes sure all data is moved from src to dest first. This is somewhat inefficient since normally all data will be fully converted. But the translation functions have no way to indicate only partial data was converted. Reported-by: Alexander Cherepanov <[email protected]> Signed-off-by: Mark Wielaard <[email protected]>
* Update elf.h from glibc.Mark Wielaard2015-04-282-10/+184
| | | | Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Don't extend ELF file size with SHT_NOBITS sh_offset.Mark Wielaard2015-03-272-4/+8
| | | | | | | | | | | | | | | | | | | | | Don't explicitly extend the file size for SHT_NOBITS sections. Since that could cause a size beyond any actual file content it will cause issues when the underlying ELF file has been mmapped or will extend the file size to increase (writing fill bytes) when not mmapped. The sh_offset value is essentially meaningless for SHT_NOBITS. gabi says that a NOBITS section sh_offset member locates the "conceptual placement" in the file. But it doesn't say this cannot be beyond the enf of the file. When ELF_F_LAYOUT is set we should trust sh_offset as given is what is wanted for an SHT_NOBITS section without extending the file size. https://bugzilla.redhat.com/show_bug.cgi?id=1020842 Buggy binutils ld could generate files where SHT_NOBITS sections have sh_offset outside the file. https://sourceware.org/bugzilla/show_bug.cgi?id=12921 Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Make __libelf_set_data_list_rdlock an internal_function.Mark Wielaard2015-02-192-1/+5
| | | | | | | | | | __libelf_set_data_list_rdlock from elf_getdata.c is marked as an internal_function in the implementation, but not in libelfP.h when it is declared. Add internal_function to the declaration. This broke the i686 build. Reported-by: Alexander Cherepanov <[email protected]> Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Consider sh_addralign 0 as 1Jan Kratochvil2015-02-072-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the Koji build for arm32 fails with: extracting debug info from /builddir/build/BUILDROOT/etcd-2.0.0-0.3.rc1.fc22.arm/usr/bin/etcd Failed to write file: invalid section alignment This is because the binary etcd http://people.redhat.com/jkratoch/etcdctl.xz contains: Section Headers: [Nr] Name Type Addr Off Size ES Flg Lk Inf Al [11] .rel.plt REL 00459ee0 449ee0 000088 08 A 13 0 0 ^ which corresponds to golang's code: go/src/cmd/ld/elf.c case EM_X86_64: sh = elfshname(".rela.plt"); sh->addralign = RegSize; default: sh = elfshname(".rel.plt"); <nothing> ELF spec says: Values 0 and 1 mean the section has no alignment constraints. and libelf/elf32_updatenull.c really parses it that way at line 204 ElfW2(LIBELFBITS,Word) sh_align = shdr->sh_addralign ?: 1; but unfortunately the later line being patched no longer does. libelf/ 2015-02-07 Jan Kratochvil <[email protected]> * elf32_updatenull.c (__elfw2(LIBELFBITS,updatenull_wrlock)): Consider sh_addralign 0 as 1. Signed-off-by: Jan Kratochvil <[email protected]>
* libelf: Make sure string returned by elf_strptr is NUL terminated.Mark Wielaard2015-02-062-2/+26
| | | | | | | | | | The result of elf_strptr is often used directly to print or strcmp the string. If the section data was truncated or corrupted that could lead to invalid memory reads possibly crashing the application. https://bugzilla.redhat.com/show_bug.cgi?id=1170810#c24 Reported-by: Alexander Cherepanov <[email protected]> Signed-off-by: Mark Wielaard <[email protected]>
* libelf: elf_strptr should use datalist when data has been added to section.Mark Wielaard2015-02-062-6/+17
| | | | | | | | | | elf_strptr always used the rawdata when available. But when data has been added to the section it should find the correct buffer in the datalist. Adds a large testcase that checks various ways of adding and extracting strings from a section. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Fix elf_newdata when raw ELF file/image data is available.Mark Wielaard2015-02-064-41/+89
| | | | | | | | | | | | | | | When ELF data for a section has been read by elf_rawdata, data_read and rawdata_base are set, but data_list_rear will not be set until the data will be converted (by elf_getdata). elf_newdata would overwrite the existing data in that case. Both elf_getdata and elf_update rely on the fact that when data_list_rear is set they don't have to look at the raw data anymore. So make sure we update the data list properly before adding any new data and raw data is available in elf_newdata. Add newdata test that calls elf_newdata before and after elf_rawdata and elf_getdata and checks the new size and contents of the section. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: elf_strptr should fetch the shdr for the section if not yet known.Mark Wielaard2015-02-062-5/+12
| | | | | | | | | elf_strptr might be called before the shdrs are read in. In that case it needs to explicitly call __elf[32|64]_getshdr_rdlock to check the section type and size. The new strptr testcase triggers this corner case and crashes before the fix. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: gelf_getphdr should check phdr index is valid.Mark Wielaard2015-01-154-28/+40
| | | | | | | | | | | | elf_getphdrnum does checks the phdrnum makes sense. But gelf_getphdr checked the given index against the "raw" e_phnum or internal __elf_getphdrnum_rdlock result without checking. Extract the checking code into a new internal __elf_getphdrnum_chk_rdlock function and use that. Found by afl-fuzz. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: ar_size cannot be negative. Fix max ar size.Mark Wielaard2015-01-122-1/+13
| | | | | | | | | | 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 <[email protected]>
* libelf: Fix dir traversal vuln in ar extraction.Alexander Cherepanov2014-12-292-4/+6
| | | | | | | | | | | | | | | | | | 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 <[email protected]>
* avoid scary command outputUlrich Drepper2014-12-182-1/+5
| | | | | | The commands to check for invalid text relocations in the generated DSOs shouldn't be displayed. They contain an echo which prints the text. This patch suppresses the commands from being printed.
* libelf: Make sure ar archive long_names len fits in mapped ELF file.Mark Wielaard2014-12-172-5/+15
| | | | Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Check index_size doesn't overflow in elf_getarsym.Mark Wielaard2014-12-172-1/+6
| | | | Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Clear any garbage left in the ar name table.Mark Wielaard2014-12-172-2/+11
| | | | Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Correct ELF64 section offset check in file_read_elf.Mark Wielaard2014-12-152-2/+6
| | | | | | | The ELF64 case didn't check for overflow and accidentially used the 32bit Shdr size. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Add some ar header sanity checking.Mark Wielaard2014-12-152-3/+18
| | | | | | Don't allow entries or size to overflow the parent file size. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Make sure n * w doesn't overflow in elf_getarsym.Mark Wielaard2014-12-122-1/+5
| | | | Signed-off-by: Mark Wielaard <[email protected]>
* Add configure --disable-textrelcheck option to enable CC=afl-fuzz on 32bit.Mark Wielaard2014-12-042-1/+5
| | | | | | | | | | | | | | | Using american fuzzy lop has found a lot of issues. It would be nice to make using it a bit easier. Our build files make sure that no shared library uses text relocations, but afl-gcc will insert some on i686. http://www.akkadia.org/drepper/textrelocs.html Now CC=afl-gcc ./configure --disable-textrelcheck will allow them so that afl can instrument the libraries. Don't try to use or install them except with afl-fuzz. When selinux is enabled it might prevent loading the libraries with DT_TEXTREL set. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Change signed overflow check to unsigned in elf_getdata_rawchunk.Mark Wielaard2014-11-262-3/+9
| | | | | | | Arithmetic of signed values that overflow causes undefined behaviour Change to explicit unsigned arithmetic overflow check. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Copy over any leftover data from src to dest in elf_cvt_note.Mark Wielaard2014-11-262-1/+11
| | | | | | | | If any data is left then the data is likely part of the truncated note name/desc. This probably means the note is corrupted, but it is better to have the actual data in dest instead of random uninitialized memory. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: elf_getphdrnum sanity check the returned phnum result.Mark Wielaard2014-11-262-0/+38
| | | | | | | | | The internal __elf_getphdrnum_rdlock might return an inconsistent phnum. Return a sanitized value, or return an error to users that rely on phnum to be consistent. That way iterating over all phdrs using elf_getphdr will return consistent results. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: Check for overflow in version_xlate elf_cvt_Verdef and elf_cvt_Verneed.Mark Wielaard2014-11-182-4/+9
| | | | Signed-off-by: Mark Wielaard <[email protected]>
* Check elf_strptr didn't fail getting section name.Mark Wielaard2014-11-172-2/+7
| | | | | | | | Since elf_strptr can fail and return NULL we should always check the result before usage. Debug sections are only handled by section name, so make sure the name actually exists. Signed-off-by: Mark Wielaard <[email protected]>
* libelf: elf_getshdrstrndx cannot use SHN_XINDEX without section headers.Mark Wielaard2014-11-172-0/+20
| | | | Signed-off-by: Mark Wielaard <[email protected]>
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