Messages in this thread Patch in this message |  | | From | Linyu Yuan <> | Subject | [PATCH 2/2] tracing/probes: make match function safe | Date | Sun, 1 May 2022 17:34:11 +0800 |
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When delete one kprobe/uprobe/eprobe event entry using /sys/kernel/debug/tracing/dynamic_events file, it will loop all dynamic envent entries, as user will not input dyn_event_operations type, when call the match function of kprobe/uprobe/eprobe, the dynamic event may have different dyn_event_operations type, but currently match function may return a match.
Fix by check dyn_event_operations type first.
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com> --- kernel/trace/trace_eprobe.c | 31 +++++++++++++++++++++++-------- kernel/trace/trace_kprobe.c | 3 +++ kernel/trace/trace_uprobe.c | 3 +++ 3 files changed, 29 insertions(+), 8 deletions(-)
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index b16e067..0029840 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -19,6 +19,21 @@ #define EPROBE_EVENT_SYSTEM "eprobes" +static int eprobe_dyn_event_create(const char *raw_command); +static int eprobe_dyn_event_show(struct seq_file *m, struct dyn_event *ev); +static bool eprobe_dyn_event_is_busy(struct dyn_event *ev); +static int eprobe_dyn_event_release(struct dyn_event *ev); +static bool eprobe_dyn_event_match(const char *system, const char *event, + int argc, const char **argv, struct dyn_event *ev); + +static struct dyn_event_operations eprobe_dyn_event_ops = { + .create = eprobe_dyn_event_create, + .show = eprobe_dyn_event_show, + .is_busy = eprobe_dyn_event_is_busy, + .free = eprobe_dyn_event_release, + .match = eprobe_dyn_event_match, +}; + struct trace_eprobe { /* tracepoint system */ const char *event_system; @@ -39,6 +54,11 @@ struct eprobe_data { static int __trace_eprobe_create(int argc, const char *argv[]); +static bool is_trace_eprobe(struct dyn_event *ev) +{ + return ev->ops == &eprobe_dyn_event_ops; +} + static void trace_event_probe_cleanup(struct trace_eprobe *ep) { if (!ep) @@ -121,6 +141,9 @@ static bool eprobe_dyn_event_match(const char *system, const char *event, struct trace_eprobe *ep = to_trace_eprobe(ev); const char *slash; + if (!is_trace_eprobe(ev)) + return false; + /* * We match the following: * event only - match all eprobes with event name @@ -174,14 +197,6 @@ static bool eprobe_dyn_event_match(const char *system, const char *event, return trace_probe_match_command_args(&ep->tp, argc, argv); } -static struct dyn_event_operations eprobe_dyn_event_ops = { - .create = eprobe_dyn_event_create, - .show = eprobe_dyn_event_show, - .is_busy = eprobe_dyn_event_is_busy, - .free = eprobe_dyn_event_release, - .match = eprobe_dyn_event_match, -}; - static struct trace_eprobe *alloc_event_probe(const char *group, const char *this_event, struct trace_event_call *event, diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 2cd8ef9..f63abfa 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -163,6 +163,9 @@ static bool trace_kprobe_match(const char *system, const char *event, { struct trace_kprobe *tk = to_trace_kprobe(ev); + if (!is_trace_kprobe(ev)) + return false; + return (event[0] == '\0' || strcmp(trace_probe_name(&tk->tp), event) == 0) && (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) && diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index a935c08..ee55ed0 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -312,6 +312,9 @@ static bool trace_uprobe_match(const char *system, const char *event, { struct trace_uprobe *tu = to_trace_uprobe(ev); + if (!is_trace_uprobe(ev)) + return false; + return (event[0] == '\0' || strcmp(trace_probe_name(&tu->tp), event) == 0) && (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) && -- 2.7.4
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