Fwd: Memory corruption bug

Hi Cristoph, Cleaned up my code and submitted bug at https://bugs.php.net/bug.php?id=69693 Pretty sure this is a PHP bug, probably related to an incomplete port to x32 ABI. Let's see what knowledgeable people can say about this. Best regards, Tiago On Wed, May 20, 2015 at 12:08 PM, Christoph Becker <cmbecker69@gmx.de> wrote: > Tiago Marques wrote: > >> I've been running a PHP server with Wordpress for a good while now, >> when I stumbled upon a problem uploading some posts, where the script >> would enter a loop and run till it crashed, running out of process >> memory. >> >> I managed to create a test case based on Wordpress's code and my HTML >> content, then narrowed down the loop and variables that are being >> (apparently) corrupted in some way: >> >> The relevant variables are $i and $l, which at the time the code blows >> up, store 68 and 71, as integers. These are summed as a parameter to >> substr() in the loop, which gets a float instead of the value "139". >> The rest of the code runs a $text var and a $newtext var, upon which >> the force_balance_tags() function from formatting.php iterates. >> These are the dumps at the time when the code does bad things: >> >> $i: int(68) >> $l: int(71) >> $i + $l: float(9.7837007760303E+18) >> >> Only the sum gives wrong results, the other operations like >> subtraction and multiplication produce accurate results. This only >> happens in this iteration of the loop. >> >> Previously, I managed to circumvent the bug by copying the $text >> variable into another variable, just before the line with the two >> substr() operations on $text, which was were the code was having >> problems. After a while of successfully posting my edits without >> knowing anything more about the problem, I noticed this might be a >> more widespread problem when Wordpress started producing garbage HTML >> on some strings, in other places, and went looking deeper. >> >> I tried to find a way to maybe debug this but have no idea of how to >> look at process memory in php, or what to look for. I have a test case >> to submit but am unsure if I should file a bug or if I'm posting in >> the right mailing list at all. > > If you have a small self-contained test case to demonstrate the erratic > behavior, I suggest you file a bug report on <https://bugs.php.net/ >>. > If you are not sure whether it is a bug in PHP, you can post the code > here. If the reproduce code is long, it might be best to post it > somewhere else (e.g. <https://gist.github.com/>), and > only send a link > to this mailing list resp. the bug tracker. > > -- > Christoph M. Becker >