From: Wenbo Zhang <ethercflow@gmail.com>
To: ast@kernel.org, daniel@iogearbox.net
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org,
linux-kernel@vger.kernel.org, ethercflow@gmail.com
Subject: [PATCH] bpf: fix fds_example SIGSEGV error
Date: Fri, 10 Jul 2020 05:20:35 -0400 [thread overview]
Message-ID: <20200710092035.28919-1-ethercflow@gmail.com> (raw)
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>
---
samples/bpf/fds_example.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/samples/bpf/fds_example.c b/samples/bpf/fds_example.c
index d5992f787232..59f45fef5110 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;
--
2.17.1
next reply other threads:[~2020-07-10 9:20 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-10 9:20 Wenbo Zhang [this message]
2020-07-10 18:46 ` [PATCH] bpf: fix fds_example SIGSEGV error Andrii Nakryiko
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