The patch 1b715e1b0ec5: "bpf: Support ->fill_link_info for
perf_event" from Jul 9, 2023, 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@xxxxxxxxxx>
Closes: https://lore.kernel.org/bpf/85697a7e-f897-4f74-8b43-82721bebc462@kili.mountain/
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
Acked-by: Yonghong Song <yonghong.song@xxxxxxxxx>
---
kernel/bpf/syscall.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 7f4e8c3..166390f 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -3378,14 +3378,14 @@ static int bpf_perf_link_fill_common(const struct perf_event *event,
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);
--
1.8.3.1
