CVE-2022-49841: linux kernel vulnerability

What is known

In the Linux kernel, the following vulnerability has been resolved: serial: imx: Add missing .thaw_noirq hook The following warning is seen with non-console UART instance when system hibernates. [ 37.371969] ------------[ cut here ]------------ [ 37.376599] uart3_root_clk already disabled [ 37.380810] WARNING: CPU: 0 PID: 296 at drivers/clk/clk.c:952 clk_core_disable+0xa4/0xb0 ... [ 37.506986] Call trace: [ 37.509432] clk_core_disable+0xa4/0xb0 [ 37.513270] clk_disable+0x34/0x50 [ 37.516672] imx_uart_thaw+0x38/0x5c [ 37.520250] platform_pm_thaw+0x30/0x6c [ 37.524089] dpm_run_callback.constprop.0+0x3c/0xd4 [ 37.528972] device_resume+0x7c/0x160 [ 37.532633] dpm_resume+0xe8/0x230 [ 37.536036] hibernation_snapshot+0x288/0x430 [ 37.540397] hibernate+0x10c/0x2e0 [ 37.543798] state_store+0xc4/0xd0 [ 37.547203] kobj_attr_store+0x1c/0x30 [ 37.550953] sysfs_kf_write+0x48/0x60 [ 37.554619] kernfs_fop_write_iter+0x118/0x1ac [ 37.559063] new_sync_write+0xe8/0x184 [ 37.562812] vfs_write+0x230/0x290 [ 37.566214] ksys_write+0x68/0xf4 [ 37.569529] __arm64_sys_write+0x20/0x2c [ 37.573452] invoke_syscall.constprop.0+0x50/0xf0 [ 37.578156] do_el0_svc+0x11c/0x150 [ 37.581648] el0_svc+0x30/0x140 [ 37.584792] el0t_64_sync_handler+0xe8/0xf0 [ 37.588976] el0t_64_sync+0x1a0/0x1a4 [ 37.592639] ---[ end trace 56e22eec54676d75 ]--- On hibernating, pm core calls into related hooks in sequence like: .freeze .freeze_noirq .thaw_noirq .thaw With .thaw_noirq hook being absent, the clock will be disabled in a unbalanced call which results the warning above. imx_uart_freeze() clk_prepare_enable() imx_uart_suspend_noirq() clk_disable() imx_uart_thaw clk_disable_unprepare() Adding the missing .thaw_noirq hook as imx_uart_resume_noirq() will have the call sequence corrected as below and thus fix the warning. imx_uart_freeze() clk_prepare_enable() imx_uart_suspend_noirq() clk_disable() imx_uart_resume_noirq() clk_enable() imx_uart_thaw clk_disable_unprepare()

Business impact

Successful exploitation of CVE-2022-49841, a medium vulnerability (CVSS 5.5) affecting linux kernel, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether linux kernel is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
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