efi/libstub: Check return value of efi_parse_options

efi_parse_options can fail if it is unable to allocate space for a copy
of the command line. Check the return value to make sure it succeeded.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-12-nivedita@alum.mit.eduSigned-off-by: Ard Biesheuvel <ardb@kernel.org>

drivers/firmware/efi/libstub/efi-stub.c

@@ -207,11 +207,21 @@ efi_status_t efi_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg)
 
 	if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
 	    IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
-	    cmdline_size == 0)
-		efi_parse_options(CONFIG_CMDLINE);
+	    cmdline_size == 0) {
+		status = efi_parse_options(CONFIG_CMDLINE);
+		if (status != EFI_SUCCESS) {
+			efi_err("Failed to parse options\n");
+			goto fail_free_cmdline;
+		}
+	}
 
-	if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0)
-		efi_parse_options(cmdline_ptr);
+	if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0) {
+		status = efi_parse_options(cmdline_ptr);
+		if (status != EFI_SUCCESS) {
+			efi_err("Failed to parse options\n");
+			goto fail_free_cmdline;
+		}
+	}
 
 	efi_info("Booting Linux Kernel...\n");
 
@@ -223,7 +233,7 @@ efi_status_t efi_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg)
 				     dram_base, image);
 	if (status != EFI_SUCCESS) {
 		efi_err("Failed to relocate kernel\n");
-		goto fail_free_cmdline;
+		goto fail_free_screeninfo;
 	}
 
 	efi_retrieve_tpm2_eventlog();
@@ -326,8 +336,9 @@ efi_status_t efi_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg)
 fail_free_image:
 	efi_free(image_size, image_addr);
 	efi_free(reserve_size, reserve_addr);
-fail_free_cmdline:
+fail_free_screeninfo:
 	free_screen_info(si);
+fail_free_cmdline:
 	efi_free(cmdline_size, (unsigned long)cmdline_ptr);
 fail:
 	return status;

drivers/firmware/efi/libstub/x86-stub.c

@@ -739,12 +739,20 @@ unsigned long efi_main(efi_handle_t handle,
 	}
 
 #ifdef CONFIG_CMDLINE_BOOL
-	efi_parse_options(CONFIG_CMDLINE);
+	status = efi_parse_options(CONFIG_CMDLINE);
+	if (status != EFI_SUCCESS) {
+		efi_err("Failed to parse options\n");
+		goto fail;
+	}
 #endif
 	if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
 		unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |
 					       ((u64)boot_params->ext_cmd_line_ptr << 32));
-		efi_parse_options((char *)cmdline_paddr);
+		status = efi_parse_options((char *)cmdline_paddr);
+		if (status != EFI_SUCCESS) {
+			efi_err("Failed to parse options\n");
+			goto fail;
+		}
 	}
 
 	/*