powerpc/powernv: Restrict OPAL symbol map to only be readable by root

Currently the OPAL symbol map is globally readable, which seems bad as
it contains physical addresses.

Restrict it to root.

Fixes: c8742f85125d ("powerpc/powernv: Expose OPAL firmware symbol map")
Cc: stable@vger.kernel.org # v3.19+
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190503075253.22798-1-ajd@linux.ibm.com

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index aba443be7daafd07f80016b969fa957694050e42..d271accf224b5b0e9b78718c4cc7d206205a99be 100644 (file)
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -705,7 +705,10 @@ static ssize_t symbol_map_read(struct file *fp, struct kobject *kobj,
                                       bin_attr->size);
 }
 
-static BIN_ATTR_RO(symbol_map, 0);
+static struct bin_attribute symbol_map_attr = {
+       .attr = {.name = "symbol_map", .mode = 0400},
+       .read = symbol_map_read
+};
 
 static void opal_export_symmap(void)
 {
@@ -722,10 +725,10 @@ static void opal_export_symmap(void)
                return;
 
        /* Setup attributes */
-       bin_attr_symbol_map.private = __va(be64_to_cpu(syms[0]));
-       bin_attr_symbol_map.size = be64_to_cpu(syms[1]);
+       symbol_map_attr.private = __va(be64_to_cpu(syms[0]));
+       symbol_map_attr.size = be64_to_cpu(syms[1]);
 
-       rc = sysfs_create_bin_file(opal_kobj, &bin_attr_symbol_map);
+       rc = sysfs_create_bin_file(opal_kobj, &symbol_map_attr);
        if (rc)
                pr_warn("Error %d creating OPAL symbols file\n", rc);
 }