| Message ID | 152346402306.4030.13915529680179697046.stgit@warthog.procyon.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 0244973ee544..7457f2676c6d 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2031,6 +2031,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN)) return -EPERM; + if (kernel_is_locked_down("BPF")) + return -EPERM; + err = check_uarg_tail_zero(uattr, sizeof(attr), size); if (err) return err;
There are some bpf functions can be used to read kernel memory: bpf_probe_read, bpf_probe_write_user and bpf_trace_printk. These allow private keys in kernel memory (e.g. the hibernation image signing key) to be read by an eBPF program. Completely prohibit the use of BPF when the kernel is locked down. Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: netdev@vger.kernel.org cc: Chun-Yi Lee <jlee@suse.com> cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> --- kernel/bpf/syscall.c | 3 +++ 1 file changed, 3 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html