drm/xe/oa: Fix potential UAF in xe_oa_add_config_ioctl()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: drm/xe/oa: Fix potential UAF in xe_oa_add_config_ioctl() In xe_oa_add_config_ioctl(), we accessed oa_config->id after dropping metrics_lock. Since this lock protects the lifetime of oa_config, an attacker could guess the id and call xe_oa_remove_config_ioctl() with perfect timing, freeing oa_config before we dereference it, leading to a potential use-after-free. Fix this by caching the id in a local variable while holding the lock. v2: (Matt A) - Dropped mutex_unlock(&oa->metrics_lock) ordering change from xe_oa_remove_config_ioctl() (cherry picked from commit 28aeaed130e8e587fd1b73b6d66ca41ccc5a1a31)

References

• https://git.kernel.org/stable/c/c6d30b65b7a44dac52ad49513268adbf19eab4a2
• https://git.kernel.org/stable/c/7cdb9a9da935c687563cc682155461fef5f9b48d
• https://git.kernel.org/stable/c/dcb171931954c51a1a7250d558f02b8f36570783