acpi/nfit: Fix race accessing memdev in nfit_get_smbios_id() (0919871a) · Commits · 戴 / test

Possible race accessing memdev structures after dropping the mutex. Dan Williams says this could race against another thread that is doing: # echo "ACPI0012:00" > /sys/bus/acpi/drivers/nfit/unbind Reported-by:

Jane Chu <jane.chu@oracle.com> Fixes: ("acpi, nfit: Add function to look up nvdimm...") Signed-off-by:

Tony Luck <tony.luck@intel.com> Signed-off-by:

Dan Williams <dan.j.williams@intel.com>

drivers/acpi/nfit/core.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -714,6 +714,7 @@ int nfit_get_smbios_id(u32 device_handle, u16 *flags)
		struct acpi_nfit_memory_map *memdev;
		struct acpi_nfit_desc *acpi_desc;
		struct nfit_mem *nfit_mem;
		u16 physical_id;

		mutex_lock(&acpi_desc_lock);
		list_for_each_entry(acpi_desc, &acpi_descs, list) {
		@@ -721,10 +722,11 @@ int nfit_get_smbios_id(u32 device_handle, u16 *flags)
		list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
		memdev = __to_nfit_memdev(nfit_mem);
		if (memdev->device_handle == device_handle) {
		*flags = memdev->flags;
		physical_id = memdev->physical_id;
		mutex_unlock(&acpi_desc->init_mutex);
		mutex_unlock(&acpi_desc_lock);
		*flags = memdev->flags;
		return memdev->physical_id;
		return physical_id;
		}
		}
		mutex_unlock(&acpi_desc->init_mutex);

Admin message