From: Leo Yan leo.yan@linaro.org
[ Upstream commit 600c787dbf6521d8d07ee717ab7606d5070103ea ]
Based on the following report from Smatch, fix the potential dereferencing freed memory check.
tools/perf/util/annotate.c:1125 disasm_line__parse() error: dereferencing freed memory 'namep'
tools/perf/util/annotate.c 1100 static int disasm_line__parse(char *line, const char **namep, char **rawp) 1101 { 1102 char tmp, *name = ltrim(line);
[...]
1114 *namep = strdup(name); 1115 1116 if (*namep == NULL) 1117 goto out_free_name;
[...]
1124 out_free_name: 1125 free((void *)namep); ^^^^^ 1126 *namep = NULL; ^^^^^^ 1127 return -1; 1128 }
If strdup() fails to allocate memory space for *namep, we don't need to free memory with pointer 'namep', which is resident in data structure disasm_line::ins::name; and *namep is NULL pointer for this failure, so it's pointless to assign NULL to *namep again.
Committer note:
Freeing namep, which is the address of the first entry of the 'struct ins' that is the first member of struct disasm_line would in fact free that disasm_line instance, if it was allocated via malloc/calloc, which, later, would a dereference of freed memory.
Signed-off-by: Leo Yan leo.yan@linaro.org Acked-by: Jiri Olsa jolsa@kernel.org Cc: Adrian Hunter adrian.hunter@intel.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Alexey Budankov alexey.budankov@linux.intel.com Cc: Alexios Zavras alexios.zavras@intel.com Cc: Andi Kleen ak@linux.intel.com Cc: Changbin Du changbin.du@intel.com Cc: David S. Miller davem@davemloft.net Cc: Davidlohr Bueso dave@stgolabs.net Cc: Eric Saint-Etienne eric.saint.etienne@oracle.com Cc: Jin Yao yao.jin@linux.intel.com Cc: Konstantin Khlebnikov khlebnikov@yandex-team.ru Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Rasmus Villemoes linux@rasmusvillemoes.dk Cc: Song Liu songliubraving@fb.com Cc: Suzuki Poulouse suzuki.poulose@arm.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Thomas Richter tmricht@linux.ibm.com Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20190702103420.27540-5-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/annotate.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c index 09762985c713..b56282041f41 100644 --- a/tools/perf/util/annotate.c +++ b/tools/perf/util/annotate.c @@ -1115,16 +1115,14 @@ static int disasm_line__parse(char *line, const char **namep, char **rawp) *namep = strdup(name);
if (*namep == NULL) - goto out_free_name; + goto out;
(*rawp)[0] = tmp; *rawp = ltrim(*rawp);
return 0;
-out_free_name: - free((void *)namep); - *namep = NULL; +out: return -1; }