libdraw: replace hand-rolled realloc, preventing buffer overflow.

The original buffer is f->nsubf*sizeof *subf bytes (oldsize) large.
Once it's full, a new buffer of (f->nsubf+DSUBF)*sizeof *subf
(newsize) is mallocated.  Unfortunately memmove() reads (newsize)
bytes from the original (oldsize) buffer, causing a buffer overflow.

By switching to realloc(), we don't need to do buffer size calculation,
memmoving, and freeing of the original buffer.

Change-Id: Ibf85bc06abe1c8275b11acb1d7d346a14291d2cd
Reviewed-on: https://plan9port-review.googlesource.com/1520
Reviewed-by: Gleydson Soares <gsoares@gmail.com>

0 files changed, 0 insertions, 0 deletions