diff options
| author | Nick Clifton <nickc@redhat.com> | 2021-04-29 17:41:43 +0100 |
|---|---|---|
| committer | Nick Clifton <nickc@redhat.com> | 2021-04-29 17:41:43 +0100 |
| commit | 063e75c9e4307d21b787a71b6d5b61a2560f5073 (patch) | |
| tree | 654ec96b82519cdc9a82f1b976507bf9cc6f693e /bfd/som.c | |
| parent | 89ba430c6b4cba43a2e77fe9a103e26e6c96bc12 (diff) | |
| download | binutils-gdb-063e75c9e4307d21b787a71b6d5b61a2560f5073.tar.gz | |
Fix illegal memory accesses when parsing a corrupt SOM format file.
PR 27792
* som.c (som_slurp_string_table): Place a terminating NUL byte at
the end of the table.
(som_slurp_symbol_table): Check for an over-large offset into the
string string table.
Diffstat (limited to 'bfd/som.c')
| -rw-r--r-- | bfd/som.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/bfd/som.c b/bfd/som.c index 5308ac5aa9e..656ded96b69 100644 --- a/bfd/som.c +++ b/bfd/som.c @@ -4576,9 +4576,11 @@ som_slurp_string_table (bfd *abfd) if (bfd_seek (abfd, obj_som_str_filepos (abfd), SEEK_SET) != 0) return false; amt = obj_som_stringtab_size (abfd); - stringtab = (char *) _bfd_malloc_and_read (abfd, amt, amt); + stringtab = (char *) _bfd_malloc_and_read (abfd, amt + 1, amt); if (stringtab == NULL) return false; + /* Make sure that the strings are zero-terminated. */ + stringtab[amt] = 0; /* Save our results and return success. */ obj_som_stringtab (abfd) = stringtab; @@ -4697,6 +4699,7 @@ som_slurp_symbol_table (bfd *abfd) (flags >> SOM_SYMBOL_TYPE_SH) & SOM_SYMBOL_TYPE_MASK; unsigned int symbol_scope = (flags >> SOM_SYMBOL_SCOPE_SH) & SOM_SYMBOL_SCOPE_MASK; + bfd_vma offset; /* I don't think we care about these. */ if (symbol_type == ST_SYM_EXT || symbol_type == ST_ARG_EXT) @@ -4728,7 +4731,14 @@ som_slurp_symbol_table (bfd *abfd) /* Some reasonable defaults. */ sym->symbol.the_bfd = abfd; - sym->symbol.name = bfd_getb32 (bufp->name) + stringtab; + offset = bfd_getb32 (bufp->name); + if (offset < obj_som_stringtab_size (abfd)) + sym->symbol.name = offset + stringtab; + else + { + bfd_set_error (bfd_error_bad_value); + goto error_return; + } sym->symbol.value = bfd_getb32 (bufp->symbol_value); sym->symbol.section = 0; sym->symbol.flags = 0; @@ -4795,7 +4805,6 @@ som_slurp_symbol_table (bfd *abfd) /* Check for a weak symbol. */ if (flags & SOM_SYMBOL_SECONDARY_DEF) sym->symbol.flags |= BSF_WEAK; - /* Mark section symbols and symbols used by the debugger. Note $START$ is a magic code symbol, NOT a section symbol. */ if (sym->symbol.name[0] == '$' @@ -4809,7 +4818,6 @@ som_slurp_symbol_table (bfd *abfd) } else if (startswith (sym->symbol.name, "L$0\001")) sym->symbol.flags |= BSF_DEBUGGING; - /* Note increment at bottom of loop, since we skip some symbols we can not include it as part of the for statement. */ sym++; |