From 26500475ac1b499d8636ff281311d633909f5d20 Mon Sep 17 00:00:00 2001 From: Tycho Andersen Date: Wed, 11 Oct 2017 09:39:21 -0600 Subject: 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 CC: Kees Cook CC: Andy Lutomirski CC: Oleg Nesterov Signed-off-by: Kees Cook --- kernel/seccomp.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'kernel/seccomp.c') 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 -- cgit