diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index 2a11e9d91dfa..eb8f6cb84c10 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -36,6 +36,9 @@ struct sk_msg_sg { struct scatterlist data[MAX_MSG_FRAGS + 1]; }; +/* UAPI in filter.c depends on struct sk_msg_sg being first element. If + * this is moved filter.c also must be updated. + */ struct sk_msg { struct sk_msg_sg sg; void *data; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 1d324c2cbca2..91c43884f295 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2665,6 +2665,7 @@ struct sk_msg_md { __u32 local_ip6[4]; /* Stored in network byte order */ __u32 remote_port; /* Stored in network byte order */ __u32 local_port; /* stored in host byte order */ + __u32 size; /* Total size of sk_msg */ }; struct sk_reuseport_md { diff --git a/net/core/filter.c b/net/core/filter.c index f9348806e843..3a3b21726fb5 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -7530,6 +7530,12 @@ static u32 sk_msg_convert_ctx_access(enum bpf_access_type type, *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->dst_reg, offsetof(struct sock_common, skc_num)); break; + + case offsetof(struct sk_msg_md, size): + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_msg_sg, size), + si->dst_reg, si->src_reg, + offsetof(struct sk_msg_sg, size)); + break; } return insn - insn_buf; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 1d324c2cbca2..91c43884f295 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -2665,6 +2665,7 @@ struct sk_msg_md { __u32 local_ip6[4]; /* Stored in network byte order */ __u32 remote_port; /* Stored in network byte order */ __u32 local_port; /* stored in host byte order */ + __u32 size; /* Total size of sk_msg */ }; struct sk_reuseport_md { diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index cf242734e2eb..7865b94c02c4 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -1843,10 +1843,20 @@ static struct bpf_test tests[] = { .prog_type = BPF_PROG_TYPE_SK_SKB, }, { - "invalid 64B read of family in SK_MSG", + "valid access size in SK_MSG", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, + offsetof(struct sk_msg_md, size)), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .prog_type = BPF_PROG_TYPE_SK_MSG, + }, + { + "invalid 64B read of size in SK_MSG", .insns = { BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_1, - offsetof(struct sk_msg_md, family)), + offsetof(struct sk_msg_md, size)), BPF_EXIT_INSN(), }, .errstr = "invalid bpf_context access", @@ -1857,7 +1867,7 @@ static struct bpf_test tests[] = { "invalid read past end of SK_MSG", .insns = { BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, - offsetof(struct sk_msg_md, local_port) + 4), + offsetof(struct sk_msg_md, size) + 4), BPF_EXIT_INSN(), }, .errstr = "R0 !read_ok",