03e54f100d
* Load/attach a BPF program that hooks to file_mprotect (int) and bprm_committed_creds (void). * Perform an action that triggers the hook. * Verify if the audit event was received using the shared global variables for the process executed. * Verify if the mprotect returns a -EPERM. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Brendan Jackman <jackmanb@google.com> Reviewed-by: Florent Revest <revest@google.com> Reviewed-by: Thomas Garnier <thgarnie@google.com> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200329004356.27286-8-kpsingh@chromium.org
49 lines
905 B
C
49 lines
905 B
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright 2020 Google LLC.
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*/
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#include "vmlinux.h"
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_tracing.h>
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#include <errno.h>
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char _license[] SEC("license") = "GPL";
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int monitored_pid = 0;
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int mprotect_count = 0;
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int bprm_count = 0;
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SEC("lsm/file_mprotect")
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int BPF_PROG(test_int_hook, struct vm_area_struct *vma,
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unsigned long reqprot, unsigned long prot, int ret)
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{
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if (ret != 0)
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return ret;
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__u32 pid = bpf_get_current_pid_tgid() >> 32;
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int is_heap = 0;
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is_heap = (vma->vm_start >= vma->vm_mm->start_brk &&
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vma->vm_end <= vma->vm_mm->brk);
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if (is_heap && monitored_pid == pid) {
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mprotect_count++;
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ret = -EPERM;
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}
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return ret;
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}
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SEC("lsm/bprm_committed_creds")
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int BPF_PROG(test_void_hook, struct linux_binprm *bprm)
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{
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__u32 pid = bpf_get_current_pid_tgid() >> 32;
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if (monitored_pid == pid)
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bprm_count++;
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return 0;
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}
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