From: Leo Yan <leo....@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....@linaro.org> Acked-by: Jiri Olsa <jo...@kernel.org> Cc: Adrian Hunter <adrian.hun...@intel.com> Cc: Alexander Shishkin <alexander.shish...@linux.intel.com> Cc: Alexey Budankov <alexey.budan...@linux.intel.com> Cc: Alexios Zavras <alexios.zav...@intel.com> Cc: Andi Kleen <a...@linux.intel.com> Cc: Changbin Du <changbin...@intel.com> Cc: David S. Miller <da...@davemloft.net> Cc: Davidlohr Bueso <d...@stgolabs.net> Cc: Eric Saint-Etienne <eric.saint.etie...@oracle.com> Cc: Jin Yao <yao....@linux.intel.com> Cc: Konstantin Khlebnikov <khlebni...@yandex-team.ru> Cc: Mathieu Poirier <mathieu.poir...@linaro.org> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Rasmus Villemoes <li...@rasmusvillemoes.dk> Cc: Song Liu <songliubrav...@fb.com> Cc: Suzuki Poulouse <suzuki.poul...@arm.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Thomas Richter <tmri...@linux.ibm.com> Cc: linux-arm-ker...@lists.infradead.org Link: http://lkml.kernel.org/r/20190702103420.27540-5-leo....@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> Signed-off-by: Sasha Levin <sas...@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; } -- 2.20.1