diff options
| author | Serge Hallyn <serge@hallyn.com> | 2025-11-14 04:32:36 +0000 |
|---|---|---|
| committer | Serge Hallyn <sergeh@kernel.org> | 2025-11-18 18:00:19 -0600 |
| commit | 9891d2f79a9fe9b77ad290f950eb8fa3e375330e (patch) | |
| tree | 08882b763689bb2228e43b411e93bd874057e7e9 /security | |
| parent | 211ddde0823f1442e4ad052a2f30f050145ccada (diff) | |
Clarify the rootid_owns_currentns
Split most of the rootid_owns_currentns() functionality
into a more generic rootid_owns_ns() function which
will be easier to write tests for.
Rename the functions and variables to make clear that
the ids being tested could be any uid.
Signed-off-by: Serge Hallyn <serge@hallyn.com>
CC: Ryan Foster <foster.ryan.r@gmail.com>
CC: Christian Brauner <brauner@kernel.org>
---
v2: change the function parameter documentation to mollify the bot.
Diffstat (limited to 'security')
| -rw-r--r-- | security/commoncap.c | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/security/commoncap.c b/security/commoncap.c index 6bd4adeb4795..496e054c5d37 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -358,17 +358,17 @@ int cap_inode_killpriv(struct mnt_idmap *idmap, struct dentry *dentry) return error; } -static bool rootid_owns_currentns(vfsuid_t rootvfsuid) +/** + * kuid_root_in_ns - check whether the given kuid is root in the given ns + * @kuid: the kuid to be tested + * @ns: the user namespace to test against + * + * Returns true if @kuid represents the root user in @ns, false otherwise. + */ +static bool kuid_root_in_ns(kuid_t kuid, struct user_namespace *ns) { - struct user_namespace *ns; - kuid_t kroot; - - if (!vfsuid_valid(rootvfsuid)) - return false; - - kroot = vfsuid_into_kuid(rootvfsuid); - for (ns = current_user_ns();; ns = ns->parent) { - if (from_kuid(ns, kroot) == 0) + for (;; ns = ns->parent) { + if (from_kuid(ns, kuid) == 0) return true; if (ns == &init_user_ns) break; @@ -377,6 +377,16 @@ static bool rootid_owns_currentns(vfsuid_t rootvfsuid) return false; } +static bool vfsuid_root_in_currentns(vfsuid_t vfsuid) +{ + kuid_t kuid; + + if (!vfsuid_valid(vfsuid)) + return false; + kuid = vfsuid_into_kuid(vfsuid); + return kuid_root_in_ns(kuid, current_user_ns()); +} + static __u32 sansflags(__u32 m) { return m & ~VFS_CAP_FLAGS_EFFECTIVE; @@ -481,7 +491,7 @@ int cap_inode_getsecurity(struct mnt_idmap *idmap, goto out_free; } - if (!rootid_owns_currentns(vfsroot)) { + if (!vfsuid_root_in_currentns(vfsroot)) { size = -EOVERFLOW; goto out_free; } @@ -722,7 +732,7 @@ int get_vfs_caps_from_disk(struct mnt_idmap *idmap, /* Limit the caps to the mounter of the filesystem * or the more limited uid specified in the xattr. */ - if (!rootid_owns_currentns(rootvfsuid)) + if (!vfsuid_root_in_currentns(rootvfsuid)) return -ENODATA; cpu_caps->permitted.val = le32_to_cpu(caps->data[0].permitted); |