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| author | Alexei Starovoitov <ast@kernel.org> | 2020-05-14 02:03:54 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-05-15 18:29:41 +0300 |
| commit | 2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366 (patch) | |
| tree | 6f2c093168b9b2c532127994bd50ff9f8e82401e /drivers/media/rc | |
| parent | a17b53c4a4b55ec322c132b6670743612229ee9c (diff) | |
| download | linux-2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366.tar.xz | |
bpf: Implement CAP_BPF
Implement permissions as stated in uapi/linux/capability.h
In order to do that the verifier allow_ptr_leaks flag is split
into four flags and they are set as:
env->allow_ptr_leaks = bpf_allow_ptr_leaks();
env->bypass_spec_v1 = bpf_bypass_spec_v1();
env->bypass_spec_v4 = bpf_bypass_spec_v4();
env->bpf_capable = bpf_capable();
The first three currently equivalent to perfmon_capable(), since leaking kernel
pointers and reading kernel memory via side channel attacks is roughly
equivalent to reading kernel memory with cap_perfmon.
'bpf_capable' enables bounded loops, precision tracking, bpf to bpf calls and
other verifier features. 'allow_ptr_leaks' enable ptr leaks, ptr conversions,
subtraction of pointers. 'bypass_spec_v1' disables speculative analysis in the
verifier, run time mitigations in bpf array, and enables indirect variable
access in bpf programs. 'bypass_spec_v4' disables emission of sanitation code
by the verifier.
That means that the networking BPF program loaded with CAP_BPF + CAP_NET_ADMIN
will have speculative checks done by the verifier and other spectre mitigation
applied. Such networking BPF program will not be able to leak kernel pointers
and will not be able to access arbitrary kernel memory.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200513230355.7858-3-alexei.starovoitov@gmail.com
Diffstat (limited to 'drivers/media/rc')
| -rw-r--r-- | drivers/media/rc/bpf-lirc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/media/rc/bpf-lirc.c b/drivers/media/rc/bpf-lirc.c index 069c42f22a8c..5bb144435c16 100644 --- a/drivers/media/rc/bpf-lirc.c +++ b/drivers/media/rc/bpf-lirc.c @@ -110,7 +110,7 @@ lirc_mode2_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_get_prandom_u32: return &bpf_get_prandom_u32_proto; case BPF_FUNC_trace_printk: - if (capable(CAP_SYS_ADMIN)) + if (perfmon_capable()) return bpf_get_trace_printk_proto(); /* fall through */ default: |