[RFC 01/18] capabilities: track actually used capabilities
[Posted July 13, 2016 by jake]
| From: |
| Topi Miettinen <toiwoton-AT-gmail.com> |
| To: |
| linux-kernel-AT-vger.kernel.org |
| Subject: |
| [RFC 01/18] capabilities: track actually used capabilities |
| Date: |
| Mon, 13 Jun 2016 22:44:08 +0300 |
| Message-ID: |
| <1465847065-3577-2-git-send-email-toiwoton@gmail.com> |
| Cc: |
| Topi Miettinen <toiwoton-AT-gmail.com>, Alexander Viro <viro-AT-zeniv.linux.org.uk>, Ingo Molnar <mingo-AT-redhat.com>, Peter Zijlstra <peterz-AT-infradead.org>, Serge Hallyn <serge.hallyn-AT-canonical.com>, Andrew Morton <akpm-AT-linux-foundation.org>, Kees Cook <keescook-AT-chromium.org>, Christoph Lameter <cl-AT-linux.com>, "Serge E. Hallyn" <serge.hallyn-AT-ubuntu.com>, Andy Shevchenko <andriy.shevchenko-AT-linux.intel.com>, "Richard W.M. Jones" <rjones-AT-redhat.com>, =?UTF-8?q?Iago=20L=C3=B3pez=20Galeiras?= <iago-AT-endocode.com>, Chris Metcalf <cmetcalf-AT-ezchip.com>, Andy Lutomirski <luto-AT-kernel.org>, Jann Horn <jann-AT-thejh.net>, linux-fsdevel-AT-vger.kernel.org (open list:FILESYSTEMS (VFS and infrastructure)), linux-security-module-AT-vger.kernel.org (open list:CAPABILITIES) |
| Archive‑link: | |
Article |
Track what capabilities are actually used and present the current
situation in /proc/self/status.
Signed-off-by: Topi Miettinen <toiwoton@gmail.com>
---
fs/exec.c | 1 +
fs/proc/array.c | 1 +
include/linux/sched.h | 1 +
kernel/capability.c | 1 +
4 files changed, 4 insertions(+)
diff --git a/fs/exec.c b/fs/exec.c
index 887c1c9..ff6f644 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1269,6 +1269,7 @@ void setup_new_exec(struct linux_binprm * bprm)
if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)
set_dumpable(current->mm, suid_dumpable);
}
+ cap_clear(current->cap_used);
/* An exec changes our domain. We are no longer part of the thread
group */
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 88c7de1..cccc9ee 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -343,6 +343,7 @@ static inline void task_cap(struct seq_file *m, struct task_struct *p)
render_cap_t(m, "CapEff:\t", &cap_effective);
render_cap_t(m, "CapBnd:\t", &cap_bset);
render_cap_t(m, "CapAmb:\t", &cap_ambient);
+ render_cap_t(m, "CapUsd:\t", &p->cap_used);
}
static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6e42ada..9c48a08 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1918,6 +1918,7 @@ struct task_struct {
#ifdef CONFIG_MMU
struct task_struct *oom_reaper_list;
#endif
+ kernel_cap_t cap_used; /* Capabilities actually used */
/* CPU-specific state of this task */
struct thread_struct thread;
/*
diff --git a/kernel/capability.c b/kernel/capability.c
index 45432b5..aad8854 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -380,6 +380,7 @@ bool ns_capable(struct user_namespace *ns, int cap)
}
if (security_capable(current_cred(), ns, cap) == 0) {
+ cap_raise(current->cap_used, cap);
current->flags |= PF_SUPERPRIV;
return true;
}
--
2.8.1
--
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