[PATCH 4/4] nvmem: core: limit cell sysfs permissions to main attribute ones

[srinivas . kandagatla]

From: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>

The cell sysfs attribute should not provide more access to the nvmem
data than the main attribute itself.
For example if nvme_config::root_only was set, the cell attribute
would still provide read access to everybody.

Mask out permissions not available on the main attribute.

Fixes: 0331c611949f ("nvmem: core: Expose cells through sysfs")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
 drivers/nvmem/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 1285300ed239..f8dd7eb40fbe 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -462,7 +462,7 @@ static int nvmem_populate_sysfs_cells(struct nvmem_device *nvmem)
 						    "%s@%x,%x", entry->name,
 						    entry->offset,
 						    entry->bit_offset);
-		attrs[i].attr.mode = 0444;
+		attrs[i].attr.mode = 0444 & nvmem_bin_attr_get_umode(nvmem);
 		attrs[i].size = entry->bytes;
 		attrs[i].read = &nvmem_cell_attr_read;
 		attrs[i].private = entry;
-- 
2.25.1