In the next patch, we're going to add a way to access the underlying
filters via bpf fds. This means that we need to ref-count both the
struct seccomp_filter objects and the struct bpf_prog objects separately,
in case a process dies but a filter is still referred to by another
process.

Additionally, we mark classic converted seccomp filters as seccomp eBPF
programs, since they are a subset of what is supported in seccomp eBPF.

Signed-off-by: Tycho Andersen <[email protected]>
CC: Kees Cook <[email protected]>
CC: Will Drewry <[email protected]>
CC: Oleg Nesterov <[email protected]>
CC: Andy Lutomirski <[email protected]>
CC: Pavel Emelyanov <[email protected]>
CC: Serge E. Hallyn <[email protected]>
CC: Alexei Starovoitov <[email protected]>
CC: Daniel Borkmann <[email protected]>
---
 kernel/seccomp.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 245df6b..afaeddf 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -378,6 +378,8 @@ static struct seccomp_filter *seccomp_prepare_filter(struct 
sock_fprog *fprog)
        }
 
        atomic_set(&sfilter->usage, 1);
+       atomic_set(&sfilter->prog->aux->refcnt, 1);
+       sfilter->prog->type = BPF_PROG_TYPE_SECCOMP;
 
        return sfilter;
 }
@@ -470,7 +472,7 @@ void get_seccomp_filter(struct task_struct *tsk)
 static inline void seccomp_filter_free(struct seccomp_filter *filter)
 {
        if (filter) {
-               bpf_prog_free(filter->prog);
+               bpf_prog_put(filter->prog);
                kfree(filter);
        }
 }
-- 
2.1.4

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