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| author | Seth Forshee <seth.forshee@canonical.com> | 2015-09-23 23:16:04 +0300 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2016-06-24 18:40:31 +0300 |
| commit | d07b846f6200454c50d791796edb82660192513d (patch) | |
| tree | 0addc4233c4e08fc7ca69511761bbd2c7402c1de /include/linux/user_namespace.h | |
| parent | cc50a07a247e17db76b1f0b0ca06652556e04fa3 (diff) | |
| download | linux-d07b846f6200454c50d791796edb82660192513d.tar.xz | |
fs: Limit file caps to the user namespace of the super block
Capability sets attached to files must be ignored except in the
user namespaces where the mounter is privileged, i.e. s_user_ns
and its descendants. Otherwise a vector exists for gaining
privileges in namespaces where a user is not already privileged.
Add a new helper function, current_in_user_ns(), to test whether a user
namespace is the same as or a descendant of another namespace.
Use this helper to determine whether a file's capability set
should be applied to the caps constructed during exec.
--EWB Replaced in_userns with the simpler current_in_userns.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'include/linux/user_namespace.h')
| -rw-r--r-- | include/linux/user_namespace.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index 8297e5b341d8..9217169c64cb 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -72,6 +72,7 @@ extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); extern int proc_setgroups_show(struct seq_file *m, void *v); extern bool userns_may_setgroups(const struct user_namespace *ns); +extern bool current_in_userns(const struct user_namespace *target_ns); #else static inline struct user_namespace *get_user_ns(struct user_namespace *ns) @@ -100,6 +101,11 @@ static inline bool userns_may_setgroups(const struct user_namespace *ns) { return true; } + +static inline bool current_in_userns(const struct user_namespace *target_ns) +{ + return true; +} #endif #endif /* _LINUX_USER_H */ |