From 9af201005e9cda726dfe47332769583faf23fdc7 Mon Sep 17 00:00:00 2001 From: Gregory Detal Date: Fri, 3 May 2024 19:33:25 +0000 Subject: [PATCH] Squash to "mptcp: add bpf_mptcp_sched_ops" -- fix bpf access The current behavior allows to write to mptcp_sock at offset that is defined in mptcp_subflow_context and vice versa. This fixes this by splitting the checks for each struct type. Signed-off-by: Gregory Detal --- net/mptcp/bpf.c | 42 +++++++++++++++++++++++++----------------- 1 file changed, 25 insertions(+), 17 deletions(-) diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c index 208e5d3f066ff4..57c47bb430b1e9 100644 --- a/net/mptcp/bpf.c +++ b/net/mptcp/bpf.c @@ -47,24 +47,32 @@ static int bpf_mptcp_sched_btf_struct_access(struct bpf_verifier_log *log, size_t end; t = btf_type_by_id(reg->btf, reg->btf_id); - if (t != mptcp_sock_type && t != mptcp_subflow_type) { - bpf_log(log, "only access to mptcp sock or subflow is supported\n"); - return -EACCES; - } - switch (off) { - case offsetof(struct mptcp_sock, snd_burst): - end = offsetofend(struct mptcp_sock, snd_burst); - break; - case offsetof(struct mptcp_subflow_context, scheduled): - end = offsetofend(struct mptcp_subflow_context, scheduled); - break; - case offsetof(struct mptcp_subflow_context, avg_pacing_rate): - end = offsetofend(struct mptcp_subflow_context, avg_pacing_rate); - break; - default: - bpf_log(log, "no write support to %s at off %d\n", - t == mptcp_sock_type ? "mptcp_sock" : "mptcp_subflow_context", off); + if (t == mptcp_sock_type) { + switch (off) { + case offsetof(struct mptcp_sock, snd_burst): + end = offsetofend(struct mptcp_sock, snd_burst); + break; + default: + bpf_log(log, "no write support to mptcp_sock at off %d\n", + off); + return -EACCES; + } + } else if (t == mptcp_subflow_type) { + switch (off) { + case offsetof(struct mptcp_subflow_context, scheduled): + end = offsetofend(struct mptcp_subflow_context, scheduled); + break; + case offsetof(struct mptcp_subflow_context, avg_pacing_rate): + end = offsetofend(struct mptcp_subflow_context, avg_pacing_rate); + break; + default: + bpf_log(log, "no write support to mptcp_subflow_context at off %d\n", + off); + return -EACCES; + } + } else { + bpf_log(log, "only access to mptcp sock or subflow is supported\n"); return -EACCES; }