[PATCH v4 15/21] fs: Don't remove suid for CAP_FSETID in s_user_ns

[Seth Forshee]

Expand the check in should_remove_suid() to keep privileges for
CAP_FSETID in s_user_ns rather than init_user_ns.

Signed-off-by: Seth Forshee <seth.forshee at canonical.com>
Acked-by: Serge Hallyn <serge.hallyn at canonical.com>
---
 fs/inode.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/inode.c b/fs/inode.c
index 69b8b526c194..cd52170f9117 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1690,7 +1690,8 @@ int should_remove_suid(struct dentry *dentry)
 	if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
 		kill |= ATTR_KILL_SGID;
 
-	if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode)))
+	if (unlikely(kill && !ns_capable(dentry->d_sb->s_user_ns, CAP_FSETID) &&
+		     S_ISREG(mode)))
 		return kill;
 
 	return 0;
-- 
2.7.4