Do not assume that ids from the lower filesystem are from
init_user_ns. Instead, translate them from that filesystem's
s_user_ns and then to the shiftfs user ns.
Signed-off-by: Seth Forshee <seth.forshee@xxxxxxxxxxxxx>
---
fs/shiftfs.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/shiftfs.c b/fs/shiftfs.c
index 556594988dd2..226c03d8588b 100644
--- a/fs/shiftfs.c
+++ b/fs/shiftfs.c
@@ -613,6 +613,8 @@ static int shiftfs_getattr(const struct path *path, struct kstat *stat,
struct inode *reali = real->d_inode;
const struct inode_operations *iop = reali->i_op;
struct path newpath = { .mnt = path->dentry->d_sb->s_fs_info, .dentry = real };
+ struct user_namespace *from_ns = reali->i_sb->s_user_ns;
+ struct user_namespace *to_ns = inode->i_sb->s_user_ns;
int err = 0;
if (iop->getattr)
@@ -624,8 +626,8 @@ static int shiftfs_getattr(const struct path *path, struct kstat *stat,
return err;
/* transform the underlying id */
- stat->uid = make_kuid(inode->i_sb->s_user_ns, __kuid_val(stat->uid));
- stat->gid = make_kgid(inode->i_sb->s_user_ns, __kgid_val(stat->gid));
+ stat->uid = shift_kuid(from_ns, to_ns, stat->uid);
+ stat->gid = shift_kgid(from_ns, to_ns, stat->gid);
return 0;
}
--
2.19.1
