From: Michal Suchanek <msuchanek@xxxxxxx>
[ Upstream commit 358fcf5ddbec4e6706405847d6a666f5933a6c25 ]
When the kernel is locked down the kernel allows reading only debugfs
files with mode 444. Mode 400 is also valid but is not allowed.
Make the 444 into a mask.
Fixes: 5496197f9b08 ("debugfs: Restrict debugfs when the kernel is locked down")
Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
Link: https://lore.kernel.org/r/20220104170505.10248-1-msuchanek@xxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/debugfs/file.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 7d162b0efbf03..950c63fa4d0b2 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -147,7 +147,7 @@ static int debugfs_locked_down(struct inode *inode,
struct file *filp,
const struct file_operations *real_fops)
{
- if ((inode->i_mode & 07777) == 0444 &&
+ if ((inode->i_mode & 07777 & ~0444) == 0 &&
!(filp->f_mode & FMODE_WRITE) &&
!real_fops->unlocked_ioctl &&
!real_fops->compat_ioctl &&
--
2.34.1
