Arch Linux

Description:

libvdpau uses `secure_getenv()` to retrieve the value of the "DRI_PRIME" environment variable. `secure_getenv()` requires that `_GNU_SOURCE` be defined for it to be avaliable.

In libvdpau-1.1.1, `_GNU_SOURCE` is not defined, so the definition is not avaliable. As a result, the return value of `secure_getenv()` is assumed to be `int`, which on 64-bit platforms causes the pointer value to be truncated/sign extended, resulting in a segfault.

Gdb session with buggy libvdpau-1.1.1:

(gdb) p prime
$1 = 0xffffffffffffee8b <error: Cannot access memory at address 0xffffffffffffee8b>
(gdb) call ((char*(*)(char*))secure_getenv)("DRI_PRIME")
$2 = 0x7fffffffee8b "1"
(gdb) call secure_getenv("DRI_PRIME")
$3 = -4469


Additional info:

* Upstream commit 1cda354bdfd0c9ca107293b84b52f4464fdbedcc fixes this bug. https://cgit.freedesktop.org/vdpau/libvdpau/commit/?id=1cda354bdfd0c9ca107293b84b52f4464fdbedcc


Steps to reproduce:

- Install `vdpauinfo` (or anything that uses libvdpau).
- Run `DRI_PRIME=1 vdpauinfo`
- Observe segfault
- Apply patch, try again, observe successful output (or at least no segfault).


I've attached both the patch for libvdpau itself, and a patch to the libvdpau pkgbuild as I retrieved it today.