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| author | Eric W. Biederman <ebiederm@xmission.com> | 2012-07-27 06:21:27 -0700 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2012-11-20 04:17:40 -0800 |
| commit | 37657da3c5d4a3bbbbb9d3b78f53a8134a0abae0 (patch) | |
| tree | 8287f406233004f244d7c0add3d1d7c6fbea4525 /kernel/user_namespace.c | |
| parent | 7fa294c8991ce0ed4e713f08209eb2ce3e1044ac (diff) | |
| download | lwn-37657da3c5d4a3bbbbb9d3b78f53a8134a0abae0.tar.gz lwn-37657da3c5d4a3bbbbb9d3b78f53a8134a0abae0.zip | |
userns: Allow setting a userns mapping to your current uid.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'kernel/user_namespace.c')
| -rw-r--r-- | 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 456a6b9fba34..49096d559e08 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; |