[PATCH 5.10 083/406] bpf: Clear the probe_addr for uprobe

Greg Kroah-Hartman
2023-09-17T19:24:42Z

From: Yafang Shao <laoar.shao@gmail.com>

[ Upstream commit 5125e757e62f6c1d5478db4c2b61a744060ddf3f ]

To avoid returning uninitialized or random values when querying the file
descriptor (fd) and accessing probe_addr, it is necessary to clear the
variable prior to its use.

Fixes: 41bdc4b40ed6 ("bpf: introduce bpf subcommand BPF_TASK_FD_QUERY")
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230709025630.3735-6-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/trace_events.h | 3 ++-
kernel/trace/bpf_trace.c | 2 +-
kernel/trace/trace_uprobe.c | 3 ++-
3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index e418065c2c909..6fb20722f49b7 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -745,7 +745,8 @@ extern int perf_uprobe_init(struct perf_event *event,
extern void perf_uprobe_destroy(struct perf_event *event);
extern int bpf_get_uprobe_info(const struct perf_event *event,
u32 *fd_type, const char **filename,
- u64 *probe_offset, bool perf_type_tracepoint);
+ u64 *probe_offset, u64 *probe_addr,
+ bool perf_type_tracepoint);
#endif
extern int ftrace_profile_set_filter(struct perf_event *event, int event_id,
char *filter_str);
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 1de9a6bf84711..71e0c1bc9759e 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2174,7 +2174,7 @@ int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
#ifdef CONFIG_UPROBE_EVENTS
if (flags & TRACE_EVENT_FL_UPROBE)
err = bpf_get_uprobe_info(event, fd_type, buf,
- probe_offset,
+ probe_offset, probe_addr,
event->attr.type == PERF_TYPE_TRACEPOINT);
#endif
}
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index f6c47361c154e..60ff36f5d7f9e 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -1422,7 +1422,7 @@ static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,

int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
const char **filename, u64 *probe_offset,
- bool perf_type_tracepoint)
+ u64 *probe_addr, bool perf_type_tracepoint)
{
const char *pevent = trace_event_name(event->tp_event);
const char *group = event->tp_event->class->system;
@@ -1439,6 +1439,7 @@ int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
: BPF_FD_TYPE_UPROBE;
*filename = tu->filename;
*probe_offset = tu->offset;
+ *probe_addr = 0;
return 0;
}
#endif /* CONFIG_PERF_EVENTS */
--
2.40.1