CVE-2023-54044

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> spmi: Add a check for remove callback when removing a SPMI driver<br /> <br /> When removing a SPMI driver, there can be a crash due to NULL pointer<br /> dereference if it does not have a remove callback defined. This is<br /> one such call trace observed when removing the QCOM SPMI PMIC driver:<br /> <br /> dump_backtrace.cfi_jt+0x0/0x8<br /> dump_stack_lvl+0xd8/0x16c<br /> panic+0x188/0x498<br /> __cfi_slowpath+0x0/0x214<br /> __cfi_slowpath+0x1dc/0x214<br /> spmi_drv_remove+0x16c/0x1e0<br /> device_release_driver_internal+0x468/0x79c<br /> driver_detach+0x11c/0x1a0<br /> bus_remove_driver+0xc4/0x124<br /> driver_unregister+0x58/0x84<br /> cleanup_module+0x1c/0xc24 [qcom_spmi_pmic]<br /> __do_sys_delete_module+0x3ec/0x53c<br /> __arm64_sys_delete_module+0x18/0x28<br /> el0_svc_common+0xdc/0x294<br /> el0_svc+0x38/0x9c<br /> el0_sync_handler+0x8c/0xf0<br /> el0_sync+0x1b4/0x1c0<br /> <br /> If a driver has all its resources allocated through devm_() APIs and<br /> does not need any other explicit cleanup, it would not require a<br /> remove callback to be defined. Hence, add a check for remove callback<br /> presence before calling it when removing a SPMI driver.