From: Yafang Shao <laoar.shao@gmail.com>
Date: Sun, 13 Aug 2023 14:18:59 +0000
Subject: bpf: Fix uninitialized symbol in bpf_perf_link_fill_kprobe()
Patch-mainline: v6.6-rc1
Git-commit: 0aa35162d2a1ed7ae5303b8d91f7290d3b8b9219
References: jsc#PED-6811
The commit 1b715e1b0ec5 ("bpf: Support ->fill_link_info for perf_event") leads
to the following Smatch static checker warning:
kernel/bpf/syscall.c:3416 bpf_perf_link_fill_kprobe()
error: uninitialized symbol 'type'.
That can happens when uname is NULL. So fix it by verifying the uname when we
really need to fill it.
Fixes: 1b715e1b0ec5 ("bpf: Support ->fill_link_info for perf_event")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Closes: https://lore.kernel.org/bpf/85697a7e-f897-4f74-8b43-82721bebc462@kili.mountain
Link: https://lore.kernel.org/bpf/20230813141900.1268-2-laoar.shao@gmail.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
kernel/bpf/syscall.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -3378,14 +3378,13 @@ static int bpf_perf_link_fill_common(con
if (!ulen ^ !uname)
return -EINVAL;
- if (!uname)
- return 0;
err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
probe_offset, probe_addr);
if (err)
return err;
-
+ if (!uname)
+ return 0;
if (buf) {
len = strlen(buf);
err = bpf_copy_to_user(uname, buf, ulen, len);