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 v7 bpf-next 04/10] bpf: Protect probed address based on kptr_restrict setting
Date: Sun, 9 Jul 2023 02:56:24 +0000 [thread overview]
Message-ID: <20230709025630.3735-5-laoar.shao@gmail.com> (raw)
In-Reply-To: <20230709025630.3735-1-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>
Acked-by: Jiri Olsa <jolsa@kernel.org>
---
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 1b3fa7b854aa..249eb14d0f7a 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;
}
--
2.30.1 (Apple Git-130)
next prev parent reply other threads:[~2023-07-09 2:56 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-09 2:56 [PATCH v7 bpf-next 00/11] bpf: Support ->fill_link_info for kprobe_multi and perf_event links Yafang Shao
2023-07-09 2:56 ` [PATCH v7 bpf-next 01/10] bpf: Support ->fill_link_info for kprobe_multi Yafang Shao
2023-07-09 2:56 ` [PATCH v7 bpf-next 02/10] bpftool: Dump the kernel symbol's module name Yafang Shao
2023-07-09 2:56 ` [PATCH v7 bpf-next 03/10] bpftool: Show kprobe_multi link info Yafang Shao
2023-07-09 2:56 ` Yafang Shao [this message]
2023-07-09 2:56 ` [PATCH v7 bpf-next 05/10] bpf: Clear the probe_addr for uprobe Yafang Shao
2023-07-09 2:56 ` [PATCH v7 bpf-next 06/10] bpf: Expose symbol's respective address Yafang Shao
2023-07-09 2:56 ` [PATCH v7 bpf-next 07/10] bpf: Add a common helper bpf_copy_to_user() Yafang Shao
2023-07-09 2:56 ` [PATCH v7 bpf-next 08/10] bpf: Support ->fill_link_info for perf_event Yafang Shao
2023-07-09 2:56 ` [PATCH v7 bpf-next 09/10] bpftool: Add perf event names Yafang Shao
2023-08-29 9:20 ` Quentin Monnet
2023-08-29 14:35 ` Yafang Shao
2023-07-09 2:56 ` [PATCH v7 bpf-next 10/10] bpftool: Show perf link info Yafang Shao
2023-07-12 3:20 ` [PATCH v7 bpf-next 00/11] bpf: Support ->fill_link_info for kprobe_multi and perf_event links patchwork-bot+netdevbpf
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