From 49a7d97ce43a82f9cfa863a35ca5cc928d7caf1e Mon Sep 17 00:00:00 2001 From: kaiw Date: Wed, 21 Jul 2010 10:25:02 +0000 Subject: Perform additional checks when translating between file and memory representations of ELF types. The ELF(3) API allows applications to request a conversion that is `in-place', i.e., with source and destinations data buffers being the same. However, the file and memory sizes of ELF sections that have additional internal structure, such as those of type `Elf_Note', or `Elf_GNU_Hash_Header', can be determined only known after the type-specific headers that comprise the first few words in these sections are read and translated. Pass in the size of destination buffer to type translation routines in "libelf_convert.m4" and have these routines return an error code if the translated data would not fit inside the destination buffer. Obtained from: elftoolchain MFC after: 1 month --- lib/libelf/libelf_xlate.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'lib/libelf/libelf_xlate.c') diff --git a/lib/libelf/libelf_xlate.c b/lib/libelf/libelf_xlate.c index 362e82d..5137b2c 100644 --- a/lib/libelf/libelf_xlate.c +++ b/lib/libelf/libelf_xlate.c @@ -48,6 +48,7 @@ Elf_Data * _libelf_xlate(Elf_Data *dst, const Elf_Data *src, unsigned int encoding, int elfclass, int direction) { + int byteswap; size_t cnt, dsz, fsz, msz; uintptr_t sb, se, db, de; @@ -132,12 +133,17 @@ _libelf_xlate(Elf_Data *dst, const Elf_Data *src, unsigned int encoding, dst->d_type = src->d_type; dst->d_size = dsz; + byteswap = encoding != LIBELF_PRIVATE(byteorder); + if (src->d_size == 0 || - (db == sb && encoding == LIBELF_PRIVATE(byteorder) && fsz == msz)) + (db == sb && !byteswap && fsz == msz)) return (dst); /* nothing more to do */ - (_libelf_get_translator(src->d_type, direction, elfclass))(dst->d_buf, - src->d_buf, cnt, encoding != LIBELF_PRIVATE(byteorder)); + if (!(_libelf_get_translator(src->d_type, direction, elfclass)) + (dst->d_buf, dsz, src->d_buf, cnt, byteswap)) { + LIBELF_SET_ERROR(DATA, 0); + return (NULL); + } return (dst); } -- cgit v1.1