[PATCH 16/24] sys: __sys_setfsuid(): handle fsid mappings

[Christian Brauner]

Switch setfsuid() to lookup fsids in the fsid mappings. If no fsid mappings are
setup the behavior is unchanged, i.e. fsids are looked up in the id mappings.

Signed-off-by: Christian Brauner <christian.brauner at ubuntu.com>
---
 kernel/sys.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/sys.c b/kernel/sys.c
index a9331f101883..ae376d32c1e3 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -59,6 +59,7 @@
 #include <linux/sched/cputime.h>
 #include <linux/rcupdate.h>
 #include <linux/uidgid.h>
+#include <linux/fsuidgid.h>
 #include <linux/cred.h>
 
 #include <linux/nospec.h>
@@ -802,9 +803,9 @@ long __sys_setfsuid(uid_t uid)
 	kuid_t kuid;
 
 	old = current_cred();
-	old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
+	old_fsuid = from_kfsuid_munged(old->user_ns, old->fsuid);
 
-	kuid = make_kuid(old->user_ns, uid);
+	kuid = make_kfsuid(old->user_ns, uid);
 	if (!uid_valid(kuid))
 		return old_fsuid;
 
-- 
2.25.0