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authorTycho Andersen <tycho@docker.com>2017-10-11 09:39:21 -0600
committerKees Cook <keescook@chromium.org>2017-11-28 15:41:01 -0800
commit26500475ac1b499d8636ff281311d633909f5d20 (patch)
treee5b9fbb6661848e22324fc70678bbd432bae2688 /kernel/seccomp.c
parentf06eae831f0c1fc5b982ea200daf552810e1dd55 (diff)
ptrace, seccomp: add support for retrieving seccomp metadata
With the new SECCOMP_FILTER_FLAG_LOG, we need to be able to extract these flags for checkpoint restore, since they describe the state of a filter. So, let's add PTRACE_SECCOMP_GET_METADATA, similar to ..._GET_FILTER, which returns the metadata of the nth filter (right now, just the flags). Hopefully this will be future proof, and new per-filter metadata can be added to this struct. Signed-off-by: Tycho Andersen <tycho@docker.com> CC: Kees Cook <keescook@chromium.org> CC: Andy Lutomirski <luto@amacapital.net> CC: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'kernel/seccomp.c')
-rw-r--r--kernel/seccomp.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 99bddaf79076..61bd9dc260c8 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -1061,6 +1061,39 @@ out:
__put_seccomp_filter(filter);
return ret;
}
+
+long seccomp_get_metadata(struct task_struct *task,
+ unsigned long size, void __user *data)
+{
+ long ret;
+ struct seccomp_filter *filter;
+ struct seccomp_metadata kmd = {};
+
+ if (!capable(CAP_SYS_ADMIN) ||
+ current->seccomp.mode != SECCOMP_MODE_DISABLED) {
+ return -EACCES;
+ }
+
+ size = min_t(unsigned long, size, sizeof(kmd));
+
+ if (copy_from_user(&kmd, data, size))
+ return -EFAULT;
+
+ filter = get_nth_filter(task, kmd.filter_off);
+ if (IS_ERR(filter))
+ return PTR_ERR(filter);
+
+ memset(&kmd, 0, sizeof(kmd));
+ if (filter->log)
+ kmd.flags |= SECCOMP_FILTER_FLAG_LOG;
+
+ ret = size;
+ if (copy_to_user(data, &kmd, size))
+ ret = -EFAULT;
+
+ __put_seccomp_filter(filter);
+ return ret;
+}
#endif
#ifdef CONFIG_SYSCTL