@@ -32,6 +32,7 @@
#include <linux/ima.h>
#include <linux/dnotify.h>
#include <linux/compat.h>
+#include <linux/fsuidgid.h>
#include "internal.h"
@@ -361,8 +362,10 @@ long do_faccessat(int dfd, const char __user *filename, int mode)
if (!override_cred)
return -ENOMEM;
- override_cred->fsuid = override_cred->uid;
- override_cred->fsgid = override_cred->gid;
+ override_cred->kfsuid = override_cred->uid;
+ override_cred->kfsgid = override_cred->gid;
+ override_cred->fsuid = kuid_to_kfsuid(override_cred->user_ns, override_cred->uid);
+ override_cred->fsgid = kgid_to_kfsgid(override_cred->user_ns, override_cred->gid);
if (!issecure(SECURE_NO_SETUID_FIXUP)) {
/* Clear the capabilities if we switch to a non-root user */
@@ -626,8 +629,13 @@ static int chown_common(const struct path *path, uid_t user, gid_t group)
kuid_t uid;
kgid_t gid;
- uid = make_kuid(current_user_ns(), user);
- gid = make_kgid(current_user_ns(), group);
+ if (is_userns_visible(inode->i_sb->s_iflags)) {
+ uid = make_kuid(current_user_ns(), user);
+ gid = make_kgid(current_user_ns(), group);
+ } else {
+ uid = make_kfsuid(current_user_ns(), user);
+ gid = make_kfsgid(current_user_ns(), group);
+ }
retry_deleg:
newattrs.ia_valid = ATTR_CTIME;
Let chown_common() 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. do_faccessat() just needs to translate from real ids into fsids. Filesystems that share a superblock in all user namespaces they are mounted in will retain their old semantics even with the introduction of fsid mappings. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> --- /* v2 */ - Christian Brauner <christian.brauner@ubuntu.com>: - handle faccessat() too /* v3 */ unchanged --- fs/open.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)