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image: improve handling of unaligned section tables

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Rather than overrunning the heap, explicitly allocate the pad area for
cases where we've aligned-up the section table sizes.

Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
This commit is contained in:
Jeremy Kerr 2012-10-02 11:44:39 +08:00
parent 142ba5c1b3
commit de78e0cde9
1 changed files with 22 additions and 0 deletions
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22
src/image.c
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@ -405,6 +405,7 @@ struct image *image_load(const char *filename)
if (rc)
goto err;
reparse:
rc = image_pecoff_parse(image);
if (rc)
goto err;
@ -413,6 +414,27 @@ struct image *image_load(const char *filename)
if (rc)
goto err;
/* Some images may have incorrectly aligned sections, which get rounded
* up to a size that is larger that the image itself (and the buffer
* that we've allocated). We would have generated a warning about this,
* but we can improve our chances that the verification hash will
* succeed by padding the image out to the aligned size, and including
* the pad in the signed data.
*
* In this case, do a realloc, but that may peturb the addresses that
* we've calculated during the pecoff parsing, so we need to redo that
* too.
*/
if (image->data_size > image->size) {
image->buf = talloc_realloc(image, image->buf, uint8_t,
image->data_size);
memset(image->buf + image->size, 0,
image->data_size - image->size);
image->size = image->data_size;
goto reparse;
}
return image;
err:
talloc_free(image);