diff options
| author | Christian Brauner <christian.brauner@ubuntu.com> | 2021-01-21 14:19:23 +0100 |
|---|---|---|
| committer | Christian Brauner <christian.brauner@ubuntu.com> | 2021-01-24 14:27:16 +0100 |
| commit | 0558c1bf5a0811bf5e3753eed911a15b9bd08271 (patch) | |
| tree | bbaad2c11479beaac5328c5c3eb33241f9b3cc45 /include/linux | |
| parent | 02f92b3868a1b34ab98464e76b0e4e060474ba10 (diff) | |
capability: handle idmapped mounts
In order to determine whether a caller holds privilege over a given
inode the capability framework exposes the two helpers
privileged_wrt_inode_uidgid() and capable_wrt_inode_uidgid(). The former
verifies that the inode has a mapping in the caller's user namespace and
the latter additionally verifies that the caller has the requested
capability in their current user namespace.
If the inode is accessed through an idmapped mount map it into the
mount's user namespace. Afterwards the checks are identical to
non-idmapped inodes. If the initial user namespace is passed all
operations are a nop so non-idmapped mounts will not see a change in
behavior.
Link: https://lore.kernel.org/r/20210121131959.646623-5-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/capability.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/include/linux/capability.h b/include/linux/capability.h index b2f698915c0f..62bfa3ed84d7 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -247,8 +247,11 @@ static inline bool ns_capable_setid(struct user_namespace *ns, int cap) return true; } #endif /* CONFIG_MULTIUSER */ -extern bool privileged_wrt_inode_uidgid(struct user_namespace *ns, const struct inode *inode); -extern bool capable_wrt_inode_uidgid(const struct inode *inode, int cap); +bool privileged_wrt_inode_uidgid(struct user_namespace *ns, + struct user_namespace *mnt_userns, + const struct inode *inode); +bool capable_wrt_inode_uidgid(struct user_namespace *mnt_userns, + const struct inode *inode, int cap); extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap); extern bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns); static inline bool perfmon_capable(void) |