release/5.2.59/bpf-Fix-fds_example-SIGSEGV-error.patch

From bb81ca446659b561510346ea36eeb5e59896fde7 Mon Sep 17 00:00:00 2001
From: Wenbo Zhang <ethercflow@gmail.com>
Date: Fri, 10 Jul 2020 05:20:35 -0400
Subject: [PATCH] bpf: Fix fds_example SIGSEGV error

commit eef8a42d6ce087d1c81c960ae0d14f955b742feb upstream.

The `BPF_LOG_BUF_SIZE`'s value is `UINT32_MAX >> 8`, so define an array
with it on stack caused an overflow.

Signed-off-by: Wenbo Zhang <ethercflow@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200710092035.28919-1-ethercflow@gmail.com
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/samples/bpf/fds_example.c b/samples/bpf/fds_example.c
index e51eb060244e..2e89eb2c2688 100644
--- a/samples/bpf/fds_example.c
+++ b/samples/bpf/fds_example.c
@@ -30,6 +30,8 @@
 #define BPF_M_MAP	1
 #define BPF_M_PROG	2
 
+char bpf_log_buf[BPF_LOG_BUF_SIZE];
+
 static void usage(void)
 {
 	printf("Usage: fds_example [...]\n");
@@ -57,7 +59,6 @@ static int bpf_prog_create(const char *object)
 		BPF_EXIT_INSN(),
 	};
 	size_t insns_cnt = sizeof(insns) / sizeof(struct bpf_insn);
-	char bpf_log_buf[BPF_LOG_BUF_SIZE];
 	struct bpf_object *obj;
 	int prog_fd;
 
-- 
2.27.0