[PATCH v3 15/21] fs: Don't remove suid for CAP_FSETID in s_user_ns

From: Seth Forshee
Date: Fri Apr 22 2016 - 11:39:41 EST


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@xxxxxxxxxxxxx>
Acked-by: Serge Hallyn <serge.hallyn@xxxxxxxxxxxxx>
---
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;
--
1.9.1