From: Yafang Shao <laoar.shao@gmail.com>
To: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com,
andrii@kernel.org, martin.lau@linux.dev, song@kernel.org,
yhs@fb.com, kpsingh@kernel.org, sdf@google.com,
haoluo@google.com, jolsa@kernel.org, quentin@isovalent.com,
rostedt@goodmis.org, mhiramat@kernel.org
Cc: bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
Yafang Shao <laoar.shao@gmail.com>
Subject: [PATCH v3 bpf-next 04/10] bpf: Protect probed address based on kptr_restrict setting
Date: Mon, 12 Jun 2023 15:16:02 +0000 [thread overview]
Message-ID: <20230612151608.99661-5-laoar.shao@gmail.com> (raw)
In-Reply-To: <20230612151608.99661-1-laoar.shao@gmail.com>
The probed address can be accessed by userspace through querying the task
file descriptor (fd). However, it is crucial to adhere to the kptr_restrict
setting and refrain from exposing the address if it is not permitted.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
kernel/trace/trace_kprobe.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 59cda19..e4554db 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1551,7 +1551,10 @@ int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
} else {
*symbol = NULL;
*probe_offset = 0;
- *probe_addr = (unsigned long)tk->rp.kp.addr;
+ if (kallsyms_show_value(current_cred()))
+ *probe_addr = (unsigned long)tk->rp.kp.addr;
+ else
+ *probe_addr = 0;
}
return 0;
}
--
1.8.3.1
next prev parent reply other threads:[~2023-06-12 15:16 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-12 15:15 [PATCH v3 bpf-next 00/10] bpf: Support ->fill_link_info for kprobe_multi and perf_event links Yafang Shao
2023-06-12 15:15 ` [PATCH v3 bpf-next 01/10] bpf: Support ->fill_link_info for kprobe_multi Yafang Shao
2023-06-15 8:29 ` Jiri Olsa
2023-06-15 12:09 ` Yafang Shao
2023-06-16 17:24 ` Andrii Nakryiko
2023-06-17 2:48 ` Yafang Shao
2023-06-12 15:16 ` [PATCH v3 bpf-next 02/10] bpftool: Dump the kernel symbol's module name Yafang Shao
2023-06-13 13:41 ` Quentin Monnet
2023-06-13 14:56 ` Yafang Shao
2023-06-16 17:25 ` Andrii Nakryiko
2023-06-17 2:55 ` Yafang Shao
2023-06-12 15:16 ` [PATCH v3 bpf-next 03/10] bpftool: Show probed function in kprobe_multi link info Yafang Shao
2023-06-13 13:41 ` Quentin Monnet
2023-06-13 14:59 ` Yafang Shao
2023-06-13 22:36 ` Kui-Feng Lee
2023-06-14 2:42 ` Yafang Shao
2023-06-14 8:33 ` Quentin Monnet
2023-06-16 17:30 ` Andrii Nakryiko
2023-06-17 3:08 ` Yafang Shao
2023-06-20 17:17 ` Andrii Nakryiko
2023-06-21 1:29 ` Yafang Shao
2023-06-12 15:16 ` Yafang Shao [this message]
2023-06-12 15:16 ` [PATCH v3 bpf-next 05/10] bpf: Clear the probe_addr for uprobe Yafang Shao
2023-06-12 17:22 ` Yonghong Song
2023-06-12 15:16 ` [PATCH v3 bpf-next 06/10] bpf: Expose symbol's respective address Yafang Shao
2023-06-12 15:16 ` [PATCH v3 bpf-next 07/10] bpf: Add a common helper bpf_copy_to_user() Yafang Shao
2023-06-12 15:16 ` [PATCH v3 bpf-next 08/10] bpf: Support ->fill_link_info for perf_event Yafang Shao
2023-06-12 17:36 ` Yonghong Song
2023-06-13 2:47 ` Yafang Shao
2023-06-14 2:34 ` Kui-Feng Lee
2023-06-14 2:45 ` Yafang Shao
2023-06-16 20:36 ` Andrii Nakryiko
2023-06-17 3:13 ` Yafang Shao
2023-06-15 10:21 ` Jiri Olsa
2023-06-15 12:10 ` Yafang Shao
2023-06-12 15:16 ` [PATCH v3 bpf-next 09/10] bpftool: Add perf event names Yafang Shao
2023-06-13 13:41 ` Quentin Monnet
2023-06-13 15:01 ` Yafang Shao
2023-06-15 10:23 ` Jiri Olsa
2023-06-12 15:16 ` [PATCH v3 bpf-next 10/10] bpftool: Show probed function in perf_event link info Yafang Shao
2023-06-13 13:42 ` Quentin Monnet
2023-06-13 15:11 ` Yafang Shao
2023-06-16 20:41 ` Andrii Nakryiko
2023-06-17 3:20 ` Yafang Shao
2023-06-17 3:29 ` Yafang Shao
2023-06-15 10:04 ` [PATCH v3 bpf-next 00/10] bpf: Support ->fill_link_info for kprobe_multi and perf_event links Jiri Olsa
2023-06-15 12:09 ` Yafang Shao
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=20230612151608.99661-5-laoar.shao@gmail.com \
--to=laoar.shao@gmail.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=haoluo@google.com \
--cc=john.fastabend@gmail.com \
--cc=jolsa@kernel.org \
--cc=kpsingh@kernel.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=martin.lau@linux.dev \
--cc=mhiramat@kernel.org \
--cc=quentin@isovalent.com \
--cc=rostedt@goodmis.org \
--cc=sdf@google.com \
--cc=song@kernel.org \
--cc=yhs@fb.com \
/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;
as well as URLs for NNTP newsgroup(s).