diff options
Diffstat (limited to 'toys/posix/file.c')
| -rw-r--r-- | toys/posix/file.c | 26 |
1 files changed, 16 insertions, 10 deletions
diff --git a/toys/posix/file.c b/toys/posix/file.c index 4ff2cca7..ecb3fc43 100644 --- a/toys/posix/file.c +++ b/toys/posix/file.c @@ -37,7 +37,7 @@ static void do_elf_file(int fd) phentsize, phnum, shsize, shnum; int64_t (*elf_int)(void *ptr, unsigned size); char *map = 0; - off_t phoff, shoff; + long phoff, shoff; printf("ELF "); elf_int = (endian==2) ? peek_be : peek_le; @@ -107,11 +107,11 @@ static void do_elf_file(int fd) // We need to read the phdrs for dynamic vs static. // (Note: fields got reordered for 64 bit) - if (phoff+phnum*phentsize>TT.len) goto bad; + if (phoff<0 || phoff>TT.len || phnum*phentsize>TT.len-phoff) goto bad; for (i = 0; i<phnum; i++) { char *phdr = map+phoff+i*phentsize; int p_type = elf_int(phdr, 4); - long long p_offset, p_filesz; + unsigned long long p_offset, p_filesz; if (p_type==2 /*PT_DYNAMIC*/) dynamic = 1; if (p_type!=3 /*PT_INTERP*/ && p_type!=4 /*PT_NOTE*/) continue; @@ -121,7 +121,7 @@ static void do_elf_file(int fd) p_filesz = elf_int(phdr+16*j, 4*j); if (p_type==3 /*PT_INTERP*/) { - if (p_offset+p_filesz>TT.len) goto bad; + if (p_filesz>TT.len || p_offset>TT.len-p_filesz) goto bad; printf(", dynamic (%.*s)", (int)p_filesz, map+p_offset); } } @@ -131,12 +131,17 @@ static void do_elf_file(int fd) // Notes are in program headers *and* section headers, but some files don't // contain program headers, so we prefer to check here. // (Note: fields got reordered for 64 bit) - if (shoff+i*shnum>TT.len) goto bad; + if (shoff<0 || shoff>TT.len || shnum*shsize>TT.len-shoff) goto bad; for (i = 0; i<shnum; i++) { char *shdr = map+shoff+i*shsize; - int sh_type = elf_int(shdr+4, 4); - long sh_offset = elf_int(shdr+8+8*(bits+1), 4*(bits+1)); - int sh_size = elf_int(shdr+8+12*(bits+1), 4); + unsigned long sh_offset; + int sh_type, sh_size; + + if (shdr>map+TT.len-(8+4*(bits+1))) goto bad; + sh_type = elf_int(shdr+4, 4); + sh_offset = elf_int(shdr+8+8*(bits+1), 4*(bits+1)); + sh_size = elf_int(shdr+8+12*(bits+1), 4); + if (sh_offset>TT.len || sh_size>TT.len-sh_offset) goto bad; if (sh_type == 2 /*SHT_SYMTAB*/) { stripped = 0; @@ -151,12 +156,13 @@ static void do_elf_file(int fd) while (sh_size >= 3*4) { // Don't try to read a truncated entry. unsigned n_namesz, n_descsz, n_type, notesz; - if (sh_offset+sh_size>TT.len) goto bad; + if (note>map+TT.len-3*4) goto bad; n_namesz = elf_int(note, 4); n_descsz = elf_int(note+4, 4); n_type = elf_int(note+8, 4); notesz = 3*4 + ((n_namesz+3)&~3) + ((n_descsz+3)&~3); + if (notesz<n_namesz || notesz<n_descsz) goto bad; // Does the claimed size of this note actually fit in the section? if (notesz > sh_size) goto bad; @@ -191,7 +197,7 @@ bad: static void do_regular_file(int fd, char *name) { char *s; - int len, magic; + unsigned len, magic; // zero through elf shnum, just in case memset(toybuf, 0, 80); |