CVE-2022-49458: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-49458 affects the Linux kernel's DRM (Direct Rendering Manager) MSM driver. The vulnerability was discovered in the error handling path of msmdrmuninit() when it's called from msmdrminit(). The issue occurs when attempting to free an IRQ that was not previously requested, which happens when an error occurs before the request_irq() call (Kernel Git).

The vulnerability stems from improper IRQ handling in the MSM DRM driver. When msmdrmuninit() is called during an error in initialization, it attempts to free an IRQ resource using free_irq() without first verifying if the IRQ was actually requested. This leads to a 'Trying to free already-free IRQ' warning and potential system instability. The issue was introduced by commit f026e431cf86 'drm/msm: Convert to Linux IRQ interfaces' (Kernel Git).

The vulnerability can trigger kernel warnings and potentially lead to system instability when the MSM DRM driver initialization fails. This primarily affects systems using Qualcomm's MSM graphics hardware (Kernel Git).

The issue was fixed by adding a boolean flag irqrequested to track whether the IRQ was successfully requested, and only calling freeirq() if this flag is set. The fix was implemented in the Linux kernel through a patch that adds proper IRQ resource tracking (Kernel Git).