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| author |   Daniel Rosenberg <drosen@google.com> | 2023-05-05 18:31:32 -0700 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2023-05-06 16:42:57 -0700 |
| commit | 3881fdfed21ff129a23979c0a92df6d3c5f49aa9 (patch) | |
| tree | 0e50cd606e6abbe6d3b8374c7ff3bba922177e4a | |
| parent | selftests/bpf: Test allowing NULL buffer in dynptr slice (diff) | |
| download | wireguard-linux-3881fdfed21ff129a23979c0a92df6d3c5f49aa9.tar.xz wireguard-linux-3881fdfed21ff129a23979c0a92df6d3c5f49aa9.zip | |
selftests/bpf: Check overflow in optional buffer
This ensures we still reject invalid memory accesses in buffers that are
marked optional.
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Link: https://lore.kernel.org/r/20230506013134.2492210-4-drosen@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/testing/selftests/bpf/progs/dynptr_fail.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/dynptr_fail.c b/tools/testing/selftests/bpf/progs/dynptr_fail.c index efe4ce72d00e..c2f0e18af951 100644 --- a/tools/testing/selftests/bpf/progs/dynptr_fail.c +++ b/tools/testing/selftests/bpf/progs/dynptr_fail.c @@ -1665,3 +1665,23 @@ int clone_xdp_packet_data(struct xdp_md *xdp) return 0; } + +/* Buffers that are provided must be sufficiently long */ +SEC("?cgroup_skb/egress") +__failure __msg("memory, len pair leads to invalid memory access") +int test_dynptr_skb_small_buff(struct __sk_buff *skb) +{ + struct bpf_dynptr ptr; + char buffer[8] = {}; + __u64 *data; + + if (bpf_dynptr_from_skb(skb, 0, &ptr)) { + err = 1; + return 1; + } + + /* This may return NULL. SKB may require a buffer */ + data = bpf_dynptr_slice(&ptr, 0, buffer, 9); + + return !!data; +} |