diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2020-05-13 16:03:54 -0700 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-05-15 17:29:41 +0200 |
| commit | 2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366 (patch) | |
| tree | 6f2c093168b9b2c532127994bd50ff9f8e82401e /kernel/bpf/queue_stack_maps.c | |
| parent | a17b53c4a4b55ec322c132b6670743612229ee9c (diff) | |
| download | linux-2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366.tar.bz2 | |
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 'kernel/bpf/queue_stack_maps.c')
| -rw-r--r-- | kernel/bpf/queue_stack_maps.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/bpf/queue_stack_maps.c b/kernel/bpf/queue_stack_maps.c index 30e1373fd437..05c8e043b9d2 100644 --- a/kernel/bpf/queue_stack_maps.c +++ b/kernel/bpf/queue_stack_maps.c @@ -45,7 +45,7 @@ static bool queue_stack_map_is_full(struct bpf_queue_stack *qs) /* Called from syscall */ static int queue_stack_map_alloc_check(union bpf_attr *attr) { - if (!capable(CAP_SYS_ADMIN)) + if (!bpf_capable()) return -EPERM; /* check sanity of attributes */ |