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

[Andrew Donnellan]

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

Restrict it to root.

Suggested-by: Michael Ellerman <mpe at ellerman.id.au>
Cc: Jordan Niethe <jniethe5 at gmail.com>
Cc: Stewart Smith <stewart at linux.ibm.com>
Fixes: c8742f85125d ("powerpc/powernv: Expose OPAL firmware symbol map")
Cc: stable at vger.kernel.org
Signed-off-by: Andrew Donnellan <ajd at linux.ibm.com>
---
 arch/powerpc/platforms/powernv/opal.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 2b0eca104f86..505460a72052 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -681,7 +681,10 @@ 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)
 {
@@ -698,10 +701,10 @@ 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);
 }
-- 
2.20.1