bpf: Clear the probe_addr for uprobe

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>

diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 7c4a0b72334eb4e9eb8b476153317b984d9cc716..36de9ebec440964bf3460d3a0c20a5450f3050bf 100644 (file)
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -864,7 +864,8 @@ 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 acb3d6dd7a772edde9ba1df82f9057b744285361..31ec0e2853ec422062b04b41e56ce7ba98df152f 100644 (file)
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2384,7 +2384,7 @@ 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 8b92e34ff0c832888ef394ae91270f5cbec544c2..fd6c71450ba741d9fc0a69743476ee67fcfe0b21 100644 (file)
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -1415,7 +1415,7 @@ 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;
@@ -1432,6 +1432,7 @@ 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 */