Annotate struct fs_struct's usage count restriction
Annotate struct fs_struct's usage count to indicate the restrictions upon it.
It may not be incremented, except by clone(CLONE_FS), as this affects the
check in check_unsafe_exec() in fs/exec.c.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/fs_struct.h b/include/linux/fs_struct.h
index a97c053..18b467d 100644
--- a/include/linux/fs_struct.h
+++ b/include/linux/fs_struct.h
@@ -4,7 +4,10 @@
#include <linux/path.h>
struct fs_struct {
- atomic_t count;
+ atomic_t count; /* This usage count is used by check_unsafe_exec() for
+ * security checking purposes - therefore it may not be
+ * incremented, except by clone(CLONE_FS).
+ */
rwlock_t lock;
int umask;
struct path root, pwd;