From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Acked-by: Serge Hallyn <serge.hallyn@xxxxxxxxxxxxx> Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> --- kernel/user_namespace.c | 15 +++++++++++++++ 1 files changed, 15 insertions(+), 0 deletions(-) diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 456a6b9..49096d5 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -709,6 +709,21 @@ ssize_t proc_projid_map_write(struct file *file, const char __user *buf, size_t static bool new_idmap_permitted(struct user_namespace *ns, int cap_setid, struct uid_gid_map *new_map) { + /* Allow mapping to your own filesystem ids */ + if ((new_map->nr_extents == 1) && (new_map->extent[0].count == 1)) { + u32 id = new_map->extent[0].lower_first; + if (cap_setid == CAP_SETUID) { + kuid_t uid = make_kuid(ns->parent, id); + if (uid_eq(uid, current_fsuid())) + return true; + } + else if (cap_setid == CAP_SETGID) { + kgid_t gid = make_kgid(ns->parent, id); + if (gid_eq(gid, current_fsgid())) + return true; + } + } + /* Allow anyone to set a mapping that doesn't require privilege */ if (!cap_valid(cap_setid)) return true; -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html