From: Kees Cook keescook@chromium.org
commit 312723a0b34d6d110aa4427a982536bb36ab8471 upstream.
Since debugfs_allow is only set at boot time during __init, make it read-only after being set.
Fixes: a24c6f7bc923 ("debugfs: Add access restriction option") Cc: Peter Enderborg peter.enderborg@sony.com Reviewed-by: Peter Enderborg peter.enderborg@sony.com Signed-off-by: Kees Cook keescook@chromium.org Link: https://lore.kernel.org/r/20210405213959.3079432-1-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/debugfs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -35,7 +35,7 @@ static struct vfsmount *debugfs_mount; static int debugfs_mount_count; static bool debugfs_registered; -static unsigned int debugfs_allow = DEFAULT_DEBUGFS_ALLOW_BITS; +static unsigned int debugfs_allow __ro_after_init = DEFAULT_DEBUGFS_ALLOW_BITS;
/* * Don't allow access attributes to be changed whilst the kernel is locked down