From: Alexei Starovoitov <ast@kernel.org>
Date: Mon, 13 Mar 2023 23:58:43 +0000 (-0700)
Subject: bpf: Fix bpf_strncmp proto.
X-Git-Tag: v6.6.7~2736^2~129^2~89^2~2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c9267aa8b794c2188d49c7d7bd2990e98b2d6b84;p=platform%2Fkernel%2Flinux-starfive.git

bpf: Fix bpf_strncmp proto.

bpf_strncmp() doesn't write into its first argument.
Make sure that the verifier knows about it.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230313235845.61029-2-alexei.starovoitov@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
---

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 77d64b6..f753676 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -571,7 +571,7 @@ static const struct bpf_func_proto bpf_strncmp_proto = {
 	.func		= bpf_strncmp,
 	.gpl_only	= false,
 	.ret_type	= RET_INTEGER,
-	.arg1_type	= ARG_PTR_TO_MEM,
+	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
 	.arg2_type	= ARG_CONST_SIZE,
 	.arg3_type	= ARG_PTR_TO_CONST_STR,
 };