From: Tao Chen <chen.dylane@linux.dev>
To: kpsingh@kernel.org, mattbobrowski@google.com, ast@kernel.org,
daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev,
eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev,
john.fastabend@gmail.com, sdf@fomichev.me, haoluo@google.com,
jolsa@kernel.org, rostedt@goodmis.org, mhiramat@kernel.org,
mathieu.desnoyers@efficios.com
Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-trace-kernel@vger.kernel.org,
Tao Chen <chen.dylane@linux.dev>
Subject: [PATCH bpf-next] bpf: clear user buf when bpf_d_path failed
Date: Wed, 11 Jun 2025 23:48:58 +0800 [thread overview]
Message-ID: <20250611154859.259682-1-chen.dylane@linux.dev> (raw)
The bpf_d_path() function may fail. If it does,
clear the user buf, like bpf_probe_read etc.
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
---
kernel/trace/bpf_trace.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 0998cbbb963..bb1003cb271 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -916,11 +916,14 @@ BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
* potentially broken verifier.
*/
len = copy_from_kernel_nofault(©, path, sizeof(*path));
- if (len < 0)
+ if (len < 0) {
+ memset(buf, 0, sz);
return len;
+ }
p = d_path(©, buf, sz);
if (IS_ERR(p)) {
+ memset(buf, 0, sz);
len = PTR_ERR(p);
} else {
len = buf + sz - p;
--
2.48.1
next reply other threads:[~2025-06-11 15:49 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-11 15:48 Tao Chen [this message]
2025-06-11 17:20 ` Song Liu
2025-06-11 19:40 ` patchwork-bot+netdevbpf
2025-06-12 21:29 ` Andrii Nakryiko
2025-06-12 21:39 ` Alexei Starovoitov
2025-06-12 23:27 ` Andrii Nakryiko
2025-06-12 23:56 ` Alexei Starovoitov
2025-06-13 0:06 ` Andrii Nakryiko
2025-06-13 2:37 ` Tao Chen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250611154859.259682-1-chen.dylane@linux.dev \
--to=chen.dylane@linux.dev \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=eddyz87@gmail.com \
--cc=haoluo@google.com \
--cc=john.fastabend@gmail.com \
--cc=jolsa@kernel.org \
--cc=kpsingh@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=martin.lau@linux.dev \
--cc=mathieu.desnoyers@efficios.com \
--cc=mattbobrowski@google.com \
--cc=mhiramat@kernel.org \
--cc=rostedt@goodmis.org \
--cc=sdf@fomichev.me \
--cc=song@kernel.org \
--cc=yonghong.song@linux.dev \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®