Privilege escalation / authentication bypass (via inverted IPMI ACPI interface teardown)

Note: A full remote PoC is unlikely; this is a kernel correctness bug. Conceptual PoC: On a system with two ACPI IPMI interfaces (iface 0 and iface 1), trigger the BMC gone event for iface 1. In the buggy code, the first device encountered where ipmi_ifnum != iface (i.e., iface 0) would be killed, removing iface 0 while iface 1 remains. An attacker able to trigger this path could disrupt or misconfigure IPMI interface handling, potentially bypassing interface-based access controls if the other interface is relied upon for auth checks. A concrete PoC would require kernel-space hooking or ACPI event simulation to invoke ipmi_bmc_gone with a chosen iface number; this outline demonstrates the exploit path, not a ready-to-run remote exploit.

diff --git a/drivers/acpi/acpi_ipmi.c b/drivers/acpi/acpi_ipmi.c index 79ce6e72bf295a..2dbed92d54b30d 100644 --- a/drivers/acpi/acpi_ipmi.c +++ b/drivers/acpi/acpi_ipmi.c @@ -490,7 +490,7 @@ static void ipmi_bmc_gone(int iface) mutex_lock(&driver_data.ipmi_lock); list_for_each_entry_safe(iter, temp, &driver_data.ipmi_devices, head) { - if (iter->ipmi_ifnum != iface) { + if (iter->ipmi_ifnum == iface) { ipmi_device = iter; __ipmi_dev_kill(iter); break; diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 390ab5f1d31378..4482cf28f56aee 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -1143,7 +1143,7 @@ static int acpi_processor_get_lpi_info(struct acpi_processor *pr) return 0; } -int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) +int __weak __cpuidle acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) { return -ENODEV; } @@ -1156,7 +1156,7 @@ int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) * * Return: 0 for success or negative value for error */ -static int acpi_idle_lpi_enter(struct cpuidle_device *dev, +static int __cpuidle acpi_idle_lpi_enter(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { struct acpi_processor *pr; diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c index bc8050d8a6f51c..56df4599d3604f 100644 --- a/drivers/acpi/resource.c +++ b/drivers/acpi/resource.c @@ -871,7 +871,7 @@ bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index, EXPORT_SYMBOL_GPL(acpi_dev_resource_interrupt); /** - * acpi_dev_free_resource_list - Free resource from %acpi_dev_get_resources(). + * acpi_dev_free_resource_list - Free resource from acpi_dev_get_resources(). * @list: The head of the resource list to free. */ void acpi_dev_free_resource_list(struct list_head *list) @@ -991,7 +991,7 @@ static int __acpi_dev_get_resources(struct acpi_device *adev, * * The resultant struct resource objects are put on the list pointed to by * @list, that must be empty initially, as members of struct resource_entry - * objects. Callers of this routine should use %acpi_dev_free_resource_list() to + * objects. Callers of this routine should use acpi_dev_free_resource_list() to * free that list. * * The number of resources in the output list is returned on success, an error @@ -1032,7 +1032,7 @@ static int is_memory(struct acpi_resource *ares, void *not_used) * The resultant struct resource objects are put on the list pointed to * by @list, that must be empty initially, as members of struct * resource_entry objects. Callers of this routine should use - * %acpi_dev_free_resource_list() to free that list. + * acpi_dev_free_resource_list() to free that list. * * The number of resources in the output list is returned on success, * an error code reflecting the error condition is returned otherwise. diff --git a/drivers/acpi/riscv/cpuidle.c b/drivers/acpi/riscv/cpuidle.c index 624f9bbdb58c47..c76dbabff702e6 100644 --- a/drivers/acpi/riscv/cpuidle.c +++ b/drivers/acpi/riscv/cpuidle.c @@ -66,7 +66,7 @@ int acpi_processor_ffh_lpi_probe(unsigned int cpu) return acpi_cpu_init_idle(cpu); } -int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) +int __cpuidle acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) { u32 state = lpi->address; diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c index a625de3c3c8bee..908cc5c7e6431b 100644 --- a/drivers/acpi/sysfs.c +++ b/drivers/acpi/sysfs.c @@ -17,12 +17,12 @@ #ifdef CONFIG_ACPI_DEBUG /* * ACPI debug sysfs I/F, including: - * /sys/modules/acpi/parameters/debug_layer - * /sys/modules/acpi/parameters/debug_level - * /sys/modules/acpi/parameters/trace_method_name - * /sys/modules/acpi/parameters/trace_state - * /sys/modules/acpi/parameters/trace_debug_layer - * /sys/modules/acpi/parameters/trace_debug_level + * /sys/module/acpi/parameters/debug_layer + * /sys/module/acpi/parameters/debug_level + * /sys/module/acpi/parameters/trace_method_name + * /sys/module/acpi/parameters/trace_state + * /sys/module/acpi/parameters/trace_debug_layer + * /sys/module/acpi/parameters/trace_debug_level */ struct acpi_dlayer { @@ -269,7 +269,7 @@ module_param_call(trace_state, param_set_trace_state, param_get_trace_state, #endif /* CONFIG_ACPI_DEBUG */ -/* /sys/modules/acpi/parameters/aml_debug_output */ +/* /sys/module/acpi/parameters/aml_debug_output */ module_param_named(aml_debug_output, acpi_gbl_enable_aml_debug_object, byte, 0644);