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

commit e7de4f7b64c23e503a8c42af98d56f2a7462bd6d upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 7fb61ebc99a2d09dd8365c3e70dd64f7b3588024..c34a44e04c87974de8f4a1b092c26dde682a0d58 100644 (file)
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -579,7 +579,10 @@ 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)
 {
@@ -596,10 +599,10 @@ 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);
 }