CVE-2022-49543: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-49543 affects the Linux kernel's ath11k driver, specifically related to device wake handling in the mhi_pm_disable_transition function. The vulnerability was discovered when testing device recovery functionality in WCN6855 and QCA6390 hardware (Kernel Commit).

The issue occurs when mhi_deassert_dev_wake() is called from mhi_device_put() without a corresponding mhi_assert_dev_wake() call from __mhi_device_get_sync() during recovery. This behavior was introduced by commit 8e0559921f9a which added pm_state checks in __mhi_device_get_sync(), preventing device wake assertion until recovery completion (Kernel Commit).

The vulnerability results in kernel warnings during device recovery operations, potentially affecting system stability and debugging capabilities. The issue specifically manifests when simulating firmware crashes on affected hardware (Kernel Commit).

The issue has been fixed by adding checks in ath11k_pci_write32() and ath11k_pci_read32() functions to skip calling mhi_device_put() when mhi_device_get_sync() does not perform the wake operation. The fix was tested on WCN6855 hw2.0 PCI with WLAN.HSP.1.1-03003-QCAHSPSWPL_V1_V2_SILICONZ_LITE-2 firmware (Kernel Commit).