CVE-2022-49976

In the Linux kernel, the following vulnerability has been resolved:

platform/x86: x86-android-tablets: Fix broken touchscreen on Chuwi Hi8 with Windows BIOS

The x86-android-tablets handling for the Chuwi Hi8 is only necessary with the Android BIOS and it is causing problems with the Windows BIOS version.

Specifically when trying to register the already present touchscreen x86_acpi_irq_helper_get() calls acpi_unregister_gsi(), this breaks the working of the touchscreen and also leads to an oops:

[ 14.248946] ————[ cut here ]———— [ 14.248954] remove_proc_entry: removing non-empty directory irq/75, leaking at least MSSL0001:00 [ 14.248983] WARNING: CPU: 3 PID: 440 at fs/proc/generic.c:718 remove_proc_entry … [ 14.249293] unregister_irq_proc+0xe0/0x100 [ 14.249305] free_desc+0x29/0x70 [ 14.249312] irq_free_descs+0x4b/0x80 [ 14.249320] mp_unmap_irq+0x5c/0x60 [ 14.249329] acpi_unregister_gsi_ioapic+0x2a/0x40 [ 14.249338] x86_acpi_irq_helper_get+0x4b/0x190 [x86_android_tablets] [ 14.249355] x86_android_tablet_init+0x178/0xe34 [x86_android_tablets]

Add an init callback for the Chuwi Hi8, which detects when the Windows BIOS is in use and exits with -ENODEV in that case, fixing this.

Affected Software

References

• https://git.kernel.org/stable/c/2986c51540ed50ac654ffb5a772e546c02628c91
• https://git.kernel.org/stable/c/c77b724cddfb8ac1291a60e3e68937e62cbfc5e0