diff options
| author | Mark Wielaard <[email protected]> | 2021-12-19 15:52:32 +0100 |
|---|---|---|
| committer | Mark Wielaard <[email protected]> | 2021-12-19 15:52:32 +0100 |
| commit | aab1cc4c0313cd0a0ad9b7ecf794301126daab15 (patch) | |
| tree | 9d61955e4112b812cece40a882c7676d92e8d668 /libelf/elf_begin.c | |
| parent | 163d1e9582efa8248057b088ad9c28fc8d24512e (diff) | |
libelf: Only set shdr state when there is at least one shdr
The elf shdr state only needs to be set when scncnt is at least
one. Otherwise e_shoff can be bogus. Also use unsigned arithmetic for
checking e_shoff alignment.
Signed-off-by: Mark Wielaard <[email protected]>
Diffstat (limited to 'libelf/elf_begin.c')
| -rw-r--r-- | libelf/elf_begin.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/libelf/elf_begin.c b/libelf/elf_begin.c index bd3399de..0c9a988d 100644 --- a/libelf/elf_begin.c +++ b/libelf/elf_begin.c @@ -383,7 +383,7 @@ file_read_elf (int fildes, void *map_address, unsigned char *e_ident, if (map_address != NULL && e_ident[EI_DATA] == MY_ELFDATA && cmd != ELF_C_READ_MMAP /* We need a copy to be able to write. */ && (ALLOW_UNALIGNED - || (((uintptr_t) ((char *) ehdr + e_shoff) + || ((((uintptr_t) ehdr + e_shoff) & (__alignof__ (Elf32_Shdr) - 1)) == 0))) { if (unlikely (scncnt > 0 && e_shoff >= maxsize) @@ -395,8 +395,10 @@ file_read_elf (int fildes, void *map_address, unsigned char *e_ident, __libelf_seterrno (ELF_E_INVALID_ELF); return NULL; } - elf->state.elf32.shdr - = (Elf32_Shdr *) ((char *) ehdr + e_shoff); + + if (scncnt > 0) + elf->state.elf32.shdr + = (Elf32_Shdr *) ((char *) ehdr + e_shoff); for (size_t cnt = 0; cnt < scncnt; ++cnt) { @@ -485,15 +487,17 @@ file_read_elf (int fildes, void *map_address, unsigned char *e_ident, if (map_address != NULL && e_ident[EI_DATA] == MY_ELFDATA && cmd != ELF_C_READ_MMAP /* We need a copy to be able to write. */ && (ALLOW_UNALIGNED - || (((uintptr_t) ((char *) ehdr + e_shoff) + || ((((uintptr_t) ehdr + e_shoff) & (__alignof__ (Elf64_Shdr) - 1)) == 0))) { if (unlikely (scncnt > 0 && e_shoff >= maxsize) || unlikely (maxsize - e_shoff < scncnt * sizeof (Elf64_Shdr))) goto free_and_out; - elf->state.elf64.shdr - = (Elf64_Shdr *) ((char *) ehdr + e_shoff); + + if (scncnt > 0) + elf->state.elf64.shdr + = (Elf64_Shdr *) ((char *) ehdr + e_shoff); for (size_t cnt = 0; cnt < scncnt; ++cnt) { |