modpost: fix segfault with short symbol names

memcmp() is wrong here, the symbol name can be shorter than KSYMTAB_PFX
or CRC_PFX.
Signed-off-by: NMichal Marek <mmarek@suse.cz>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

scripts/mod/modpost.c

@@ -522,7 +522,7 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
 		break;
 	case SHN_ABS:
 		/* CRC'd symbol */
-		if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
+		if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
 			crc = (unsigned int) sym->st_value;
 			sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
 					export);
@@ -566,7 +566,7 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
 		break;
 	default:
 		/* All exported symbols */
-		if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
+		if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
 			sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
 					export);
 		}