1 files changed, 40 insertions, 21 deletions

diff --git a/drivers/acpi/apei/apei-base.c b/drivers/acpi/apei/apei-base.c
index e5d53b7ddc7e..1d3656f6919f 100644
--- a/drivers/acpi/apei/apei-base.c
+++ b/drivers/acpi/apei/apei-base.c
@@ -558,33 +558,48 @@ void apei_resources_release(struct apei_resources *resources)
 }
 EXPORT_SYMBOL_GPL(apei_resources_release);
 
-static int apei_check_gar(struct acpi_generic_address *reg, u64 *paddr)
+static int apei_check_gar(struct acpi_generic_address *reg, u64 *paddr,
+                                u32 *access_bit_width)
 {
-        u32 width, space_id;
+        u32 bit_width, bit_offset, access_size_code, space_id;
 
-        width = reg->bit_width;
+        bit_width = reg->bit_width;
+        bit_offset = reg->bit_offset;
+        access_size_code = reg->access_width;
         space_id = reg->space_id;
         /* Handle possible alignment issues */
         memcpy(paddr, &reg->address, sizeof(*paddr));
         if (!*paddr) {
                 pr_warning(FW_BUG APEI_PFX
-                           "Invalid physical address in GAR [0x%llx/%u/%u]\n",
-                           *paddr, width, space_id);
+                           "Invalid physical address in GAR [0x%llx/%u/%u/%u/%u]\n",
+                           *paddr, bit_width, bit_offset, access_size_code,
+                           space_id);
                 return -EINVAL;
         }
 
-        if ((width != 8) && (width != 16) && (width != 32) && (width != 64)) {
+        if (access_size_code < 1 || access_size_code > 4) {
                 pr_warning(FW_BUG APEI_PFX
-                           "Invalid bit width in GAR [0x%llx/%u/%u]\n",
-                           *paddr, width, space_id);
+                           "Invalid access size code in GAR [0x%llx/%u/%u/%u/%u]\n",
+                           *paddr, bit_width, bit_offset, access_size_code,
+                           space_id);
+                return -EINVAL;
+        }
+        *access_bit_width = 1UL << (access_size_code + 2);
+
+        if ((bit_width + bit_offset) > *access_bit_width) {
+                pr_warning(FW_BUG APEI_PFX
+                           "Invalid bit width + offset in GAR [0x%llx/%u/%u/%u/%u]\n",
+                           *paddr, bit_width, bit_offset, access_size_code,
+                           space_id);
                 return -EINVAL;
         }
 
         if (space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY &&
             space_id != ACPI_ADR_SPACE_SYSTEM_IO) {
                 pr_warning(FW_BUG APEI_PFX
-                           "Invalid address space type in GAR [0x%llx/%u/%u]\n",
-                           *paddr, width, space_id);
+                           "Invalid address space type in GAR [0x%llx/%u/%u/%u/%u]\n",
+                           *paddr, bit_width, bit_offset, access_size_code,
+                           space_id);
                 return -EINVAL;
         }
 
@@ -595,23 +610,25 @@ static int apei_check_gar(struct acpi_generic_address *reg, u64 *paddr)
 int apei_read(u64 *val, struct acpi_generic_address *reg)
 {
         int rc;
+        u32 access_bit_width;
         u64 address;
         acpi_status status;
 
-        rc = apei_check_gar(reg, &address);
+        rc = apei_check_gar(reg, &address, &access_bit_width);
         if (rc)
                 return rc;
 
         *val = 0;
         switch(reg->space_id) {
         case ACPI_ADR_SPACE_SYSTEM_MEMORY:
-                status = acpi_os_read_memory64((acpi_physical_address)
-                                             address, val, reg->bit_width);
+                status = acpi_os_read_memory64((acpi_physical_address) address,
+                                               val, access_bit_width);
                 if (ACPI_FAILURE(status))
                         return -EIO;
                 break;
         case ACPI_ADR_SPACE_SYSTEM_IO:
-                status = acpi_os_read_port(address, (u32 *)val, reg->bit_width);
+                status = acpi_os_read_port(address, (u32 *)val,
+                                           access_bit_width);
                 if (ACPI_FAILURE(status))
                         return -EIO;
                 break;
@@ -627,22 +644,23 @@ EXPORT_SYMBOL_GPL(apei_read);
 int apei_write(u64 val, struct acpi_generic_address *reg)
 {
         int rc;
+        u32 access_bit_width;
         u64 address;
         acpi_status status;
 
-        rc = apei_check_gar(reg, &address);
+        rc = apei_check_gar(reg, &address, &access_bit_width);
         if (rc)
                 return rc;
 
         switch (reg->space_id) {
         case ACPI_ADR_SPACE_SYSTEM_MEMORY:
-                status = acpi_os_write_memory64((acpi_physical_address)
-                                              address, val, reg->bit_width);
+                status = acpi_os_write_memory64((acpi_physical_address) address,
+                                                val, access_bit_width);
                 if (ACPI_FAILURE(status))
                         return -EIO;
                 break;
         case ACPI_ADR_SPACE_SYSTEM_IO:
-                status = acpi_os_write_port(address, val, reg->bit_width);
+                status = acpi_os_write_port(address, val, access_bit_width);
                 if (ACPI_FAILURE(status))
                         return -EIO;
                 break;
@@ -661,23 +679,24 @@ static int collect_res_callback(struct apei_exec_context *ctx,
         struct apei_resources *resources = data;
         struct acpi_generic_address *reg = &entry->register_region;
         u8 ins = entry->instruction;
+        u32 access_bit_width;
         u64 paddr;
         int rc;
 
         if (!(ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER))
                 return 0;
 
-        rc = apei_check_gar(reg, &paddr);
+        rc = apei_check_gar(reg, &paddr, &access_bit_width);
         if (rc)
                 return rc;
 
         switch (reg->space_id) {
         case ACPI_ADR_SPACE_SYSTEM_MEMORY:
                 return apei_res_add(&resources->iomem, paddr,
-                                    reg->bit_width / 8);
+                                    access_bit_width / 8);
         case ACPI_ADR_SPACE_SYSTEM_IO:
                 return apei_res_add(&resources->ioport, paddr,
-                                    reg->bit_width / 8);
+                                    access_bit_width / 8);
         default:
                 return -EINVAL;
         }