diff options
Diffstat (limited to 'libelf')
| -rw-r--r-- | libelf/ChangeLog | 7 | ||||
| -rw-r--r-- | libelf/elf32_updatenull.c | 5 | ||||
| -rw-r--r-- | libelf/elf_getdata.c | 14 |
3 files changed, 26 insertions, 0 deletions
diff --git a/libelf/ChangeLog b/libelf/ChangeLog index a7983a0a..0b9b4781 100644 --- a/libelf/ChangeLog +++ b/libelf/ChangeLog @@ -1,5 +1,12 @@ 2015-05-12 Mark Wielaard <mjw@redhat.com> + * elf32_updatenull.c (updatenull_wrlock): Check that sh_addralign + is a powerof2. + * elf_getdata.c (__libelf_set_rawdata_wrlock): Clamp large d_aligns + to the elf image offset. + +2015-05-12 Mark Wielaard <mjw@redhat.com> + * elf32_newphdr.c (newphdr): Call __libelf_seterrno with ELF_E_INVALID_INDEX before failing. Check whether section zero shdr actually exists if we need to put extended phnum in section zero. diff --git a/libelf/elf32_updatenull.c b/libelf/elf32_updatenull.c index d873a309..a0de80e1 100644 --- a/libelf/elf32_updatenull.c +++ b/libelf/elf32_updatenull.c @@ -202,6 +202,11 @@ __elfw2(LIBELFBITS,updatenull_wrlock) (Elf *elf, int *change_bop, size_t shnum) assert (shdr != NULL); ElfW2(LIBELFBITS,Word) sh_entsize = shdr->sh_entsize; ElfW2(LIBELFBITS,Word) sh_align = shdr->sh_addralign ?: 1; + if (unlikely (! powerof2 (sh_align))) + { + __libelf_seterrno (ELF_E_INVALID_ALIGN); + return -1; + } /* Set the sh_entsize value if we can reliably detect it. */ switch (shdr->sh_type) diff --git a/libelf/elf_getdata.c b/libelf/elf_getdata.c index e8f022f9..8567da1e 100644 --- a/libelf/elf_getdata.c +++ b/libelf/elf_getdata.c @@ -301,6 +301,20 @@ __libelf_set_rawdata_wrlock (Elf_Scn *scn) else scn->rawdata.d.d_type = shtype_map[LIBELF_EV_IDX][TYPEIDX (type)]; scn->rawdata.d.d_off = 0; + + /* Make sure the alignment makes sense. d_align should be aligned both + in the section (trivially true since d_off is zero) and in the file. + Unfortunately we cannot be too strict because there are ELF files + out there that fail this requirement. We will try to fix those up + in elf_update when writing out the image. But for very large + alignment values this can bloat the image considerably. So here + just check and clamp the alignment value to not be bigger than the + actual offset of the data in the file. Given that there is always + at least an ehdr this will only trigger for alignment values > 64 + which should be uncommon. */ + align = align ?: 1; + if (align > offset) + align = offset; scn->rawdata.d.d_align = align; if (elf->class == ELFCLASS32 || (offsetof (struct Elf, state.elf32.ehdr) |