From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
mainline inclusion from mainline-v5.3-rc1 commit 6f11586f4896ee448262747788a0a3faf0fe9066 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I947TK CVE: CVE-2021-46926
Reference:https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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The convention is that the SoundWire controller device is a child of the HDAudio controller. However there can be more than one child exposed in the DSDT table, and the current namespace walk returns the last (incorrect) device.
Intel documentation states that bits 28..31 of the _ADR field represent the link type, with SoundWire assigned the value 4.
Add a filter and terminate early when a valid _ADR is provided, otherwise keep iterating to find the next child.
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Liu Mingrui liumingrui@huawei.com --- drivers/soundwire/intel_init.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/soundwire/intel_init.c b/drivers/soundwire/intel_init.c index 5c8a20d99878..203192840e0b 100644 --- a/drivers/soundwire/intel_init.c +++ b/drivers/soundwire/intel_init.c @@ -12,6 +12,7 @@ #include <linux/soundwire/sdw_intel.h> #include "intel.h"
+#define SDW_LINK_TYPE 4 /* from Intel ACPI documentation */ #define SDW_MAX_LINKS 4 #define SDW_SHIM_LCAP 0x0 #define SDW_SHIM_BASE 0x2C000 @@ -149,6 +150,12 @@ static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level, { struct sdw_intel_res *res = cdata; struct acpi_device *adev; + acpi_status status; + u64 adr; + + status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &adr); + if (ACPI_FAILURE(status)) + return AE_OK; /* keep going */
if (acpi_bus_get_device(handle, &adev)) { pr_err("%s: Couldn't find ACPI handle\n", __func__); @@ -156,7 +163,19 @@ static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level, }
res->handle = handle; - return AE_OK; + + /* + * On some Intel platforms, multiple children of the HDAS + * device can be found, but only one of them is the SoundWire + * controller. The SNDW device is always exposed with + * Name(_ADR, 0x40000000), with bits 31..28 representing the + * SoundWire link so filter accordingly + */ + if ((adr & GENMASK(31, 28)) >> 28 != SDW_LINK_TYPE) + return AE_OK; /* keep going */ + + /* device found, stop namespace walk */ + return AE_CTRL_TERMINATE; }
/**