From: Christian Brauner <christian.brauner@ubuntu.com> To: "Stéphane Graber" <stgraber@ubuntu.com>, "Eric W. Biederman" <ebiederm@xmission.com>, "Aleksa Sarai" <cyphar@cyphar.com>, "Jann Horn" <jannh@google.com> Cc: smbarber@chromium.org, Alexander Viro <viro@zeniv.linux.org.uk>, Alexey Dobriyan <adobriyan@gmail.com>, Serge Hallyn <serge@hallyn.com>, James Morris <jmorris@namei.org>, Kees Cook <keescook@chromium.org>, Jonathan Corbet <corbet@lwn.net>, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, containers@lists.linux-foundation.org, linux-security-module@vger.kernel.org, linux-api@vger.kernel.org, Christian Brauner <christian.brauner@ubuntu.com> Subject: [PATCH 15/24] commoncap:cap_bprm_set_creds(): handle fsid mappings Date: Tue, 11 Feb 2020 17:57:44 +0100 [thread overview] Message-ID: <20200211165753.356508-16-christian.brauner@ubuntu.com> (raw) In-Reply-To: <20200211165753.356508-1-christian.brauner@ubuntu.com> During exec the kfsids are currently reset to the effective kids. To retain the same semantics with the introduction of fsid mappings, we lookup the userspace effective id in the id mappings and translate the effective id into the corresponding kfsid in the fsidmapping. This means, the behavior is unchanged when no fsid mappings are setup and the semantics stay the same even when fsid mappings are setup. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> --- security/commoncap.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/security/commoncap.c b/security/commoncap.c index ecfa0d0c250e..8d1a81e98610 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -811,7 +811,10 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) struct cred *new = bprm->cred; bool effective = false, has_fcap = false, is_setid; int ret; - kuid_t root_uid; + kuid_t root_uid, kfsuid; + kgid_t kfsgid; + uid_t fsuid; + gid_t fsgid; if (WARN_ON(!cap_ambient_invariant_ok(old))) return -EPERM; @@ -848,8 +851,15 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) old->cap_permitted); } - new->suid = new->fsuid = new->euid; - new->sgid = new->fsgid = new->egid; + fsuid = from_kuid_munged(new->user_ns, new->euid); + kfsuid = make_kfsuid(new->user_ns, fsuid); + new->suid = new->euid; + new->fsuid = kfsuid; + + fsgid = from_kgid_munged(new->user_ns, new->egid); + kfsgid = make_kfsgid(new->user_ns, fsgid); + new->sgid = new->egid; + new->fsgid = kfsgid; /* File caps or setid cancels ambient. */ if (has_fcap || is_setid) -- 2.25.0
WARNING: multiple messages have this Message-ID (diff)
From: Christian Brauner <christian.brauner-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org> To: "Stéphane Graber" <stgraber-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org>, "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>, "Aleksa Sarai" <cyphar-gVpy/LI/lHzQT0dZR+AlfA@public.gmane.org>, "Jann Horn" <jannh-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> Cc: smbarber-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, Alexander Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>, Alexey Dobriyan <adobriyan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Serge Hallyn <serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org>, James Morris <jmorris-gx6/JNMH7DfYtjvyW6yDsg@public.gmane.org>, Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>, Jonathan Corbet <corbet-T1hC0tSOHrs@public.gmane.org>, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Christian Brauner <christian.brauner-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org> Subject: [PATCH 15/24] commoncap:cap_bprm_set_creds(): handle fsid mappings Date: Tue, 11 Feb 2020 17:57:44 +0100 [thread overview] Message-ID: <20200211165753.356508-16-christian.brauner@ubuntu.com> (raw) In-Reply-To: <20200211165753.356508-1-christian.brauner-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org> During exec the kfsids are currently reset to the effective kids. To retain the same semantics with the introduction of fsid mappings, we lookup the userspace effective id in the id mappings and translate the effective id into the corresponding kfsid in the fsidmapping. This means, the behavior is unchanged when no fsid mappings are setup and the semantics stay the same even when fsid mappings are setup. Signed-off-by: Christian Brauner <christian.brauner-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org> --- security/commoncap.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/security/commoncap.c b/security/commoncap.c index ecfa0d0c250e..8d1a81e98610 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -811,7 +811,10 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) struct cred *new = bprm->cred; bool effective = false, has_fcap = false, is_setid; int ret; - kuid_t root_uid; + kuid_t root_uid, kfsuid; + kgid_t kfsgid; + uid_t fsuid; + gid_t fsgid; if (WARN_ON(!cap_ambient_invariant_ok(old))) return -EPERM; @@ -848,8 +851,15 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) old->cap_permitted); } - new->suid = new->fsuid = new->euid; - new->sgid = new->fsgid = new->egid; + fsuid = from_kuid_munged(new->user_ns, new->euid); + kfsuid = make_kfsuid(new->user_ns, fsuid); + new->suid = new->euid; + new->fsuid = kfsuid; + + fsgid = from_kgid_munged(new->user_ns, new->egid); + kfsgid = make_kfsgid(new->user_ns, fsgid); + new->sgid = new->egid; + new->fsgid = kfsgid; /* File caps or setid cancels ambient. */ if (has_fcap || is_setid) -- 2.25.0
next prev parent reply other threads:[~2020-02-11 16:59 UTC|newest] Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-02-11 16:57 [PATCH 00/24] user_namespace: introduce fsid mappings Christian Brauner 2020-02-11 16:57 ` [PATCH 01/24] user_namespace: introduce fsid mappings infrastructure Christian Brauner 2020-02-11 17:26 ` Randy Dunlap 2020-02-11 16:57 ` [PATCH 02/24] proc: add /proc/<pid>/fsuid_map Christian Brauner 2020-02-11 16:57 ` [PATCH 03/24] proc: add /proc/<pid>/fsgid_map Christian Brauner 2020-02-11 16:57 ` Christian Brauner 2020-02-11 16:57 ` [PATCH 04/24] fsuidgid: add fsid mapping helpers Christian Brauner 2020-02-11 16:57 ` [PATCH 05/24] proc: task_state(): use from_kfs{g,u}id_munged Christian Brauner 2020-02-11 16:57 ` [PATCH 06/24] fs: add is_userns_visible() helper Christian Brauner 2020-02-11 16:57 ` [PATCH 07/24] namei: may_{o_}create(): handle fsid mappings Christian Brauner 2020-02-11 16:57 ` [PATCH 08/24] inode: inode_owner_or_capable(): " Christian Brauner 2020-02-11 16:57 ` [PATCH 09/24] capability: privileged_wrt_inode_uidgid(): " Christian Brauner 2020-02-11 16:57 ` [PATCH 10/24] stat: " Christian Brauner 2020-02-11 16:57 ` [PATCH 11/24] open: chown_common(): " Christian Brauner 2020-02-11 16:57 ` [PATCH 12/24] posix_acl: " Christian Brauner 2020-02-11 16:57 ` [PATCH 13/24] attr: notify_change(): " Christian Brauner 2020-02-11 16:57 ` [PATCH 14/24] commoncap: cap_task_fix_setuid(): " Christian Brauner 2020-02-11 16:57 ` Christian Brauner 2020-02-11 16:57 ` Christian Brauner [this message] 2020-02-11 16:57 ` [PATCH 15/24] commoncap:cap_bprm_set_creds(): " Christian Brauner 2020-02-11 16:57 ` [PATCH 16/24] sys: __sys_setfsuid(): " Christian Brauner 2020-02-11 16:57 ` [PATCH 17/24] sys: __sys_setfsgid(): " Christian Brauner 2020-02-11 16:57 ` [PATCH 18/24] sys:__sys_setuid(): " Christian Brauner 2020-02-11 16:57 ` [PATCH 19/24] sys:__sys_setgid(): " Christian Brauner 2020-02-11 16:57 ` [PATCH 20/24] sys:__sys_setreuid(): " Christian Brauner 2020-02-11 16:57 ` [PATCH 21/24] sys:__sys_setregid(): " Christian Brauner 2020-02-11 16:57 ` Christian Brauner 2020-02-11 16:57 ` [PATCH 22/24] sys:__sys_setresuid(): " Christian Brauner 2020-02-11 16:57 ` [PATCH 23/24] sys:__sys_setresgid(): " Christian Brauner 2020-02-11 16:57 ` [PATCH 24/24] devpts: " Christian Brauner 2020-02-11 20:55 ` [PATCH 00/24] user_namespace: introduce " Jann Horn 2020-02-11 20:55 ` Jann Horn 2020-02-12 14:51 ` Christian Brauner 2020-02-12 18:53 ` Jann Horn 2020-02-12 18:53 ` Jann Horn
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