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| author | Tycho Andersen <tycho@docker.com> | 2017-10-11 17:39:21 +0200 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2017-11-29 00:41:01 +0100 |
| commit | 26500475ac1b499d8636ff281311d633909f5d20 (patch) | |
| tree | e5b9fbb6661848e22324fc70678bbd432bae2688 /kernel | |
| parent | seccomp: hoist out filter resolving logic (diff) | |
| download | linux-26500475ac1b499d8636ff281311d633909f5d20.tar.xz linux-26500475ac1b499d8636ff281311d633909f5d20.zip | |
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')
| -rw-r--r-- | kernel/ptrace.c | 4 | ||||
| -rw-r--r-- | kernel/seccomp.c | 33 |
2 files changed, 37 insertions, 0 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 84b1367935e4..58291e9f3276 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -1092,6 +1092,10 @@ int ptrace_request(struct task_struct *child, long request, ret = seccomp_get_filter(child, addr, datavp); break; + case PTRACE_SECCOMP_GET_METADATA: + ret = seccomp_get_metadata(child, addr, datavp); + break; + default: break; } 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 |