Messages in this thread | | | Date | Thu, 14 Feb 2019 05:22:39 -0500 | From | YU Bo <> | Subject | Re: [PATCH] perf trace: Fix potential USE_AFTER_FREE problem |
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Hi, On Thu, Feb 14, 2019 at 09:34:11AM +0100, Jiri Olsa wrote: >On Thu, Feb 14, 2019 at 12:23:56AM -0500, Bo YU wrote: >> From: Bo Yu <tsu.yubo@gmail.com> >> >> There is a freed pointer "evsel", so fix it. >> >> Detected by CoverityScan, CID#1442595("Memory-illegalaccesses >> (USE_AFTER_FREE)") >> Fixes: 6ab3bc240ade4("perf trace: Support multiple "vfs_getname" probes") >> >> Signed-off-by: Bo Yu <tsu.yubo@gmail.com> >> --- >> tools/perf/builtin-trace.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c >> index b36061cd1ab8..4036b20a1067 100644 >> --- a/tools/perf/builtin-trace.c >> +++ b/tools/perf/builtin-trace.c >> @@ -2515,7 +2515,7 @@ static size_t trace__fprintf_thread_summary(struct trace *trace, FILE *fp); >> static bool perf_evlist__add_vfs_getname(struct perf_evlist *evlist) >> { >> bool found = false; >> - struct perf_evsel *evsel, *tmp; >> + struct perf_evsel *evsel = NULL, *tmp; > >hum, I can't see how this change could matter, >could you pelase explain First, this is a warning reported by CoverityScan,but in fact i do not how to answer your question :(. Second, if i remember right, temporary element of list_for_each_entry_safe should be initialized with NULL otherwise it will complain via gcc. Please correct me :) Thanks, > >jirka > >> struct parse_events_error err = { .idx = 0, }; >> int ret = parse_events(evlist, "probe:vfs_getname*", &err); >> >> -- >> 2.11.0 >>
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