[Ada] ada_unpack_from_contents: Error if target buffer not large enough

This adds a guard that the size of the "unpacked" buffer is large enough
to contain at least BIT_SIZE bits.  If not, report an error.  This is to
guard this routine from doing buffer overflows when called incorrectly.

gdb/ChangeLog:

        * ada-lang.c (ada_unpack_from_contents): Add guard that unpacked
        is large enough for BIT_SIZE.  Update function comment.
This commit is contained in:
Joel Brobecker 2015-10-09 14:16:45 -07:00
parent 0cafa88cc0
commit 5b639deae1
2 changed files with 15 additions and 1 deletions

View File

@ -1,3 +1,8 @@
2015-10-09 Joel Brobecker <brobecker@adacore.com>
* ada-lang.c (ada_unpack_from_contents): Add guard that unpacked
is large enough for BIT_SIZE. Update function comment.
2015-10-09 Joel Brobecker <brobecker@adacore.com>
* ada-lang.c (ada_value_primitive_packed_val): Move

View File

@ -2383,9 +2383,12 @@ has_negatives (struct type *type)
}
/* With SRC being a buffer containing BIT_SIZE bits of data at BIT_OFFSET,
unpack that data into UNPACKED. UNPACKED_LEN is the size in bytes of
unpack that data into UNPACKED. UNPACKED_LEN is the size in bytes of
the unpacked buffer.
The size of the unpacked buffer (UNPACKED_LEN) is expected to be large
enough to contain at least BIT_OFFSET bits. If not, an error is raised.
IS_BIG_ENDIAN is nonzero if the data is stored in big endian mode,
zero otherwise.
@ -2417,6 +2420,12 @@ ada_unpack_from_contents (const gdb_byte *src, int bit_offset, int bit_size,
the indices move. */
int delta = is_big_endian ? -1 : 1;
/* Make sure that unpacked is large enough to receive the BIT_SIZE
bits from SRC. .*/
if ((bit_size + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT > unpacked_len)
error (_("Cannot unpack %d bits into buffer of %d bytes"),
bit_size, unpacked_len);
srcBitsLeft = bit_size;
src_bytes_left = src_len;
unpacked_bytes_left = unpacked_len;