[PATCH net 2/2] bpf: fix two missing target_size settings in bpf_convert_ctx_access
flat view
STALE3353d
From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2017-08-11 16:31:32
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
When CONFIG_NET_SCHED or CONFIG_NET_RX_BUSY_POLL is /not/ set and
we try a narrow __sk_buff load of tc_index or napi_id, respectively,
then verifier rightfully complains that it's misconfigured, because
we need to set target_size in each of the two cases. The rewrite
for the ctx access is just a dummy op, but needs to pass, so fix
this up.
Fixes: f96da09473b5 ("bpf: simplify narrower ctx access")
Reported-by: Shubham Bansal <redacted>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
net/core/filter.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/core/filter.c b/net/core/filter.c
index f44fc22..6280a60 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -3505,6 +3505,7 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type, bpf_target_off(struct sk_buff, tc_index, 2, target_size)); #else + *target_size = 2; if (type == BPF_WRITE) *insn++ = BPF_MOV64_REG(si->dst_reg, si->dst_reg); else
@@ -3520,6 +3521,7 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type, *insn++ = BPF_JMP_IMM(BPF_JGE, si->dst_reg, MIN_NAPI_ID, 1); *insn++ = BPF_MOV64_IMM(si->dst_reg, 0); #else + *target_size = 4; *insn++ = BPF_MOV64_IMM(si->dst_reg, 0); #endif break;
--
1.9.3