Bug #80457 [Opn->Csd]: stream_get_contents() fails with maxlength=-1 or default

Edit report at https://bugs.php.net/bug.php?id=80457&edit=1 ID: 80457 Updated by: nikic@php.net Reported by: bruno dot premont at restena dot lu Summary: stream_get_contents() fails with maxlength=-1 or default -Status: Open +Status: Closed Type: Bug Package: Filesystem function related Operating System: Linux, x32 PHP Version: 7.3.25 Block user comment: N Private report: N New Comment: Automatic comment on behalf of nikita.ppv@gmail.com Revision: http://git.php.net/?p=php-src.git;a=commit;h=d6fcaf5da4368918936a875876e0639b7e6f3bd2 Log: Fixed bug #80457 Previous Comments: ------------------------------------------------------------------------ [2020-12-01 16:28:43] bruno dot premont at restena dot lu @cmb: If I had a public git repo I could offer a pull request, though I don't, thus the patch. I didn't check if PHP-7.4.x or PHP-8 are affected too, but I guess they are. Yes, X32 is a Linux ABI on x86_64. What I was more surprised is about size_t and ssize_t being 32bit and not 64bit as plain x86_64 while off_t is 64bit. ------------------------------------------------------------------------ [2020-12-01 15:57:12] nikic@php.net @cmb: Note that x32 != x86. x32 is a Linux ABI for ... x64. ------------------------------------------------------------------------ [2020-12-01 15:52:22] cmb@php.net > Under X32 zend_long is 64bit […] That shouldn't be the case. What's the value of PHP_INT_SIZE on that system? That said, the patch looks good to me. Care to provide a PR? ------------------------------------------------------------------------ [2020-12-01 15:28:30] bruno dot premont at restena dot lu Description: ------------ The change introduced in commit 62dce97973436f1830b18304e7939a03b18d44ba (Require non-negative length in stream_get_contents()) causes stream_get_contents() to fail if no maxlength is provided and even if maxlength is explicitly provided as -1. This also causes some stream tests to fail. The cause of the failure is the mix of type conversions where parts are signed and parts are unsigned. Under X32 zend_long is 64bit but size_t and ssize_t seem not to be. Thus zend_long maxlength = (ssize_t)PHP_STREAM_COPY_ALL; will store -1 but maxlength == PHP_STREAM_COPY_ALL will compare a signed and a unsigned value causing trouble due to extending unsigned 32bit PHP_STREAM_COPY_ALL to a signed 64bit value. Blindly converting between unsigned PHP_STREAM_COPY_ALL and signed zend_long is prone to trouble. Other probably affected code: phar extension (passing zend_long to php_stream_copy_to_mem() which takes a size_t for maxlength after eventually having assigned PHP_STREAM_COPY_ALL to the zend_long. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=80457&edit=1