diff options
| author | Mark Wielaard <mark@klomp.org> | 2020-12-16 10:57:22 +0100 |
|---|---|---|
| committer | Mark Wielaard <mark@klomp.org> | 2020-12-16 11:01:52 +0100 |
| commit | d21692c7ebc4d511d1b40e9c0cc8d95c590c2070 (patch) | |
| tree | 5d439c4b29a72eef9e78aab4eb96843747cba930 /libelf | |
| parent | a5b95a38b77d7e9387945d06a2b6318c1aa6f5a4 (diff) | |
| download | elfutils-d21692c7ebc4d511d1b40e9c0cc8d95c590c2070.tar.gz | |
libelf: Make sure we have at least a full ELF header available.
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>
Diffstat (limited to 'libelf')
| -rw-r--r-- | libelf/ChangeLog | 4 | ||||
| -rw-r--r-- | libelf/elf_begin.c | 7 |
2 files changed, 11 insertions, 0 deletions
diff --git a/libelf/ChangeLog b/libelf/ChangeLog index 41727fbd..a280a262 100644 --- a/libelf/ChangeLog +++ b/libelf/ChangeLog @@ -1,3 +1,7 @@ +2020-12-15 Mark Wielaard <mark@klomp.org> + + * elf_begin.c (get_shnum): Make sure the full Ehdr is available. + 2020-12-12 Dmitry V. Levin <ldv@altlinux.org> * common.h: Fix spelling typo in comment. diff --git a/libelf/elf_begin.c b/libelf/elf_begin.c index 43828c9a..32648c15 100644 --- a/libelf/elf_begin.c +++ b/libelf/elf_begin.c @@ -88,6 +88,13 @@ get_shnum (void *map_address, unsigned char *e_ident, int fildes, } ehdr_mem; bool is32 = e_ident[EI_CLASS] == ELFCLASS32; + if ((is32 && maxsize < sizeof (Elf32_Ehdr)) + || (!is32 && maxsize < sizeof (Elf64_Ehdr))) + { + __libelf_seterrno (ELF_E_INVALID_ELF); + return (size_t) -1l; + } + /* Make the ELF header available. */ if (e_ident[EI_DATA] == MY_ELFDATA && (ALLOW_UNALIGNED |