Re: RFC on proposal fix [Re: Crash caused by insert-file-contents, both trunk (bzr 111532) and 24.2.92 affected]

[Dmitry Antipov]

On 01/17/2013 09:50 PM, Eli Zaretskii wrote:

> Can you tell which problems you found in the original code that these
> changes are supposed to fix?

1) Original code do emacs_read to ((char *) BEG_ADDR + PT_BYTE - BEG_BYTE + 
offset
   without adjusting gap size, z and zv; this (IIUC) fools make_gap and so
   enlarge_buffer_text; we end up with the gap which is less than expected,
   read_non_regular do emacs_read into the buffer beyond allocated buffer text,
   which finally causes EFAULT from emacs_read or heap corruption.

2) Original code throws I/O error too early without decoding the data possibly
   read before. When not-yet-decoded part of buffer text is displayed, redisplay
   is likely to crash.

Dmitry