diff options
Diffstat (limited to 'libelf/elf_begin.c')
| -rw-r--r-- | libelf/elf_begin.c | 69 |
1 files changed, 49 insertions, 20 deletions
diff --git a/libelf/elf_begin.c b/libelf/elf_begin.c index 6f850382..b20ab4f3 100644 --- a/libelf/elf_begin.c +++ b/libelf/elf_begin.c @@ -158,6 +158,7 @@ get_shnum (void *map_address, unsigned char *e_ident, int fildes, off_t offset, else { Elf32_Word size; + ssize_t r; if (likely (map_address != NULL)) /* gcc will optimize the memcpy to a simple memory @@ -167,11 +168,19 @@ get_shnum (void *map_address, unsigned char *e_ident, int fildes, off_t offset, + offset))->sh_size, sizeof (Elf32_Word)); else - if (unlikely (pread_retry (fildes, &size, sizeof (Elf32_Word), - offset + ehdr.e32->e_shoff - + offsetof (Elf32_Shdr, sh_size)) + if (unlikely ((r = pread_retry (fildes, &size, + sizeof (Elf32_Word), + offset + ehdr.e32->e_shoff + + offsetof (Elf32_Shdr, + sh_size))) != sizeof (Elf32_Word))) - return (size_t) -1l; + { + if (r < 0) + __libelf_seterrno (ELF_E_INVALID_FILE); + else + __libelf_seterrno (ELF_E_INVALID_ELF); + return (size_t) -1l; + } if (e_ident[EI_DATA] != MY_ELFDATA) CONVERT (size); @@ -207,6 +216,7 @@ get_shnum (void *map_address, unsigned char *e_ident, int fildes, off_t offset, + offset))->sh_size; else { + ssize_t r; if (likely (map_address != NULL)) /* gcc will optimize the memcpy to a simple memory access while taking care of alignment issues. */ @@ -215,19 +225,30 @@ get_shnum (void *map_address, unsigned char *e_ident, int fildes, off_t offset, + offset))->sh_size, sizeof (Elf64_Xword)); else - if (unlikely (pread_retry (fildes, &size, sizeof (Elf64_Xword), - offset + ehdr.e64->e_shoff - + offsetof (Elf64_Shdr, sh_size)) + if (unlikely ((r = pread_retry (fildes, &size, + sizeof (Elf64_Xword), + offset + ehdr.e64->e_shoff + + offsetof (Elf64_Shdr, + sh_size))) != sizeof (Elf64_Xword))) - return (size_t) -1l; + { + if (r < 0) + __libelf_seterrno (ELF_E_INVALID_FILE); + else + __libelf_seterrno (ELF_E_INVALID_ELF); + return (size_t) -1l; + } if (e_ident[EI_DATA] != MY_ELFDATA) CONVERT (size); } if (size > ~((GElf_Word) 0)) - /* Invalid value, it is too large. */ - return (size_t) -1l; + { + /* Invalid value, it is too large. */ + __libelf_seterrno (ELF_E_INVALID_ELF); + return (size_t) -1l; + } result = size; } @@ -255,11 +276,13 @@ file_read_elf (int fildes, void *map_address, unsigned char *e_ident, && e_ident[EI_DATA] != ELFDATA2MSB))) { /* Cannot handle this. */ - __libelf_seterrno (ELF_E_INVALID_FILE); + __libelf_seterrno (ELF_E_INVALID_ELF); return NULL; } - /* Determine the number of sections. */ + /* Determine the number of sections. Returns -1 and sets libelf errno + if the file handle or elf file is invalid. Returns zero if there + are no section headers (or they cannot be read). */ size_t scncnt = get_shnum (map_address, e_ident, fildes, offset, maxsize); if (scncnt == (size_t) -1l) /* Could not determine the number of sections. */ @@ -269,10 +292,16 @@ file_read_elf (int fildes, void *map_address, unsigned char *e_ident, if (e_ident[EI_CLASS] == ELFCLASS32) { if (scncnt > SIZE_MAX / (sizeof (Elf_Scn) + sizeof (Elf32_Shdr))) - return NULL; + { + __libelf_seterrno (ELF_E_INVALID_ELF); + return NULL; + } } else if (scncnt > SIZE_MAX / (sizeof (Elf_Scn) + sizeof (Elf64_Shdr))) - return NULL; + { + __libelf_seterrno (ELF_E_INVALID_ELF); + return NULL; + } /* We can now allocate the memory. Even if there are no section headers, we allocate space for a zeroth section in case we need it later. */ @@ -281,7 +310,7 @@ file_read_elf (int fildes, void *map_address, unsigned char *e_ident, Elf *elf = allocate_elf (fildes, map_address, offset, maxsize, cmd, parent, ELF_K_ELF, scnmax * sizeof (Elf_Scn)); if (elf == NULL) - /* Not enough memory. */ + /* Not enough memory. allocate_elf will have set libelf errno. */ return NULL; assert ((unsigned int) scncnt == scncnt); @@ -344,13 +373,13 @@ file_read_elf (int fildes, void *map_address, unsigned char *e_ident, || (((uintptr_t) ((char *) ehdr + e_shoff) & (__alignof__ (Elf32_Shdr) - 1)) == 0))) { - if (unlikely (e_shoff >= maxsize) + if (unlikely (scncnt > 0 && e_shoff >= maxsize) || unlikely (maxsize - e_shoff < scncnt * sizeof (Elf32_Shdr))) { free_and_out: free (elf); - __libelf_seterrno (ELF_E_INVALID_FILE); + __libelf_seterrno (ELF_E_INVALID_ELF); return NULL; } elf->state.elf32.shdr @@ -446,7 +475,7 @@ file_read_elf (int fildes, void *map_address, unsigned char *e_ident, || (((uintptr_t) ((char *) ehdr + e_shoff) & (__alignof__ (Elf64_Shdr) - 1)) == 0))) { - if (unlikely (e_shoff >= maxsize) + if (unlikely (scncnt > 0 && e_shoff >= maxsize) || unlikely (maxsize - e_shoff < scncnt * sizeof (Elf64_Shdr))) goto free_and_out; @@ -582,7 +611,7 @@ read_unmmaped_file (int fildes, off_t offset, size_t maxsize, Elf_Cmd cmd, ? sizeof (Elf32_Ehdr) : sizeof (Elf64_Ehdr))) return file_read_elf (fildes, NULL, mem.header, offset, maxsize, cmd, parent); - /* FALLTHROUGH */ + FALLTHROUGH; default: break; @@ -1097,7 +1126,7 @@ elf_begin (int fildes, Elf_Cmd cmd, Elf *ref) retval = NULL; break; } - /* FALLTHROUGH */ + FALLTHROUGH; case ELF_C_READ: case ELF_C_READ_MMAP: |