Bug #80457 [Opn]: stream_get_contents() fails with maxlength=-1 or default
Edit report at https://bugs.php.net/bug.php?id=80457&edit=1
ID: 80457
User updated by: bruno dot premont at restena dot lu
Reported by: bruno dot premont at restena dot lu
Summary: stream_get_contents() fails with maxlength=-1 or
default
Status: Open
Type: Bug
Package: Filesystem function related
Operating System: Linux, x32
PHP Version: 7.3.25
Block user comment: N
Private report: N
New Comment:
@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.
Previous Comments:
------------------------------------------------------------------------
[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 [â¦]
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
Thread (5 messages)