Patch "perf parse-events: Fix incorrect conversion of 'if () free()' to 'zfree()'" has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    perf parse-events: Fix incorrect conversion of 'if () free()' to 'zfree()'

to the 5.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     perf-parse-events-fix-incorrect-conversion-of-if-fre.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 8dbb125df1a9a3ef386611634ed3c850771f5e93
Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Date:   Wed May 13 10:20:26 2020 -0300

    perf parse-events: Fix incorrect conversion of 'if () free()' to 'zfree()'
    
    [ Upstream commit 7fcdccd4237724931d9773d1e3039bfe053a6f52 ]
    
    When applying a patch by Ian I incorrectly converted to zfree() an
    expression that involved testing some other struct member, not the one
    being freed, which lead to bugs reproduceable by:
    
      $ perf stat -e i/bs,tsc,L2/o sleep 1
      WARNING: multiple event parsing errors
      Segmentation fault (core dumped)
      $
    
    Fix it by restoring the test for pos->free_str before freeing
    pos->val.str, but continue using zfree(&pos->val.str) to set that member
    to NULL after freeing it.
    
    Reported-by: Ian Rogers <irogers@xxxxxxxxxx>
    Fixes: e8dfb81838b1 ("perf parse-events: Fix memory leaks found on parse_events")
    Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
    Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
    Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
    Cc: clang-built-linux@xxxxxxxxxxxxxxxx
    Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
    Cc: Leo Yan <leo.yan@xxxxxxxxxx>
    Cc: Mark Rutland <mark.rutland@xxxxxxx>
    Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
    Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
    Cc: Stephane Eranian <eranian@xxxxxxxxxx>
    Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index f3b10b8449010..ca9006cd4bf18 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -1370,7 +1370,8 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
 
 		list_for_each_entry_safe(pos, tmp, &config_terms, list) {
 			list_del_init(&pos->list);
-			zfree(&pos->val.str);
+			if (pos->free_str)
+				zfree(&pos->val.str);
 			free(pos);
 		}
 		return -EINVAL;