From 94e81d1a4bd9cd516da84d060536226a6578565c Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Wed, 6 Dec 2023 15:27:06 -0800 Subject: [PATCH] bpf: sockmap, updating the sg structure should also update curr [ Upstream commit bb9aefde5bbaf6c168c77ba635c155b4980c2287 ] Curr pointer should be updated when the sg structure is shifted. Fixes: 7246d8ed4dcce ("bpf: helper to pop data from messages") Signed-off-by: John Fastabend Link: https://lore.kernel.org/r/20231206232706.374377-3-john.fastabend@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/core/filter.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/net/core/filter.c b/net/core/filter.c index b149a16..90fe3e7 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2591,6 +2591,22 @@ BPF_CALL_2(bpf_msg_cork_bytes, struct sk_msg *, msg, u32, bytes) return 0; } +static void sk_msg_reset_curr(struct sk_msg *msg) +{ + u32 i = msg->sg.start; + u32 len = 0; + + do { + len += sk_msg_elem(msg, i)->length; + sk_msg_iter_var_next(i); + if (len >= msg->sg.size) + break; + } while (i != msg->sg.end); + + msg->sg.curr = i; + msg->sg.copybreak = 0; +} + static const struct bpf_func_proto bpf_msg_cork_bytes_proto = { .func = bpf_msg_cork_bytes, .gpl_only = false, @@ -2710,6 +2726,7 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start, msg->sg.end - shift + NR_MSG_FRAG_IDS : msg->sg.end - shift; out: + sk_msg_reset_curr(msg); msg->data = sg_virt(&msg->sg.data[first_sge]) + start - offset; msg->data_end = msg->data + bytes; return 0; @@ -2846,6 +2863,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start, msg->sg.data[new] = rsge; } + sk_msg_reset_curr(msg); sk_msg_compute_data_pointers(msg); return 0; } @@ -3014,6 +3032,7 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start, sk_mem_uncharge(msg->sk, len - pop); msg->sg.size -= (len - pop); + sk_msg_reset_curr(msg); sk_msg_compute_data_pointers(msg); return 0; } -- 2.7.4