[PATCH 4.4 07/79] powerpc/powernv: Restrict OPAL symbol map to only be readable by root

From: Greg Kroah-Hartman
Date: Wed Oct 16 2019 - 17:53:30 EST


From: Andrew Donnellan <ajd@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxx # v3.19+
Suggested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Donnellan <ajd@xxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20190503075253.22798-1-ajd@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/powerpc/platforms/powernv/opal.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -580,7 +580,10 @@ static ssize_t symbol_map_read(struct fi
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)
{
@@ -597,10 +600,10 @@ 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);
}