From: Ian Rogers irogers@google.com
[ Upstream commit 266150c94c69429cf6d18e130237224a047f5061 ]
Realloc of size zero is a free not an error, avoid this causing a double free. Caught by clang's address sanitizer:
==2634==ERROR: AddressSanitizer: attempting double-free on 0x6020000015f0 in thread T0: #0 0x5649659297fd in free llvm/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:123:3 #1 0x5649659e9251 in __zfree tools/lib/zalloc.c:13:2 #2 0x564965c0f92c in mem2node__exit tools/perf/util/mem2node.c:114:2 #3 0x564965a08b4c in perf_c2c__report tools/perf/builtin-c2c.c:2867:2 #4 0x564965a0616a in cmd_c2c tools/perf/builtin-c2c.c:2989:10 #5 0x564965944348 in run_builtin tools/perf/perf.c:312:11 #6 0x564965943235 in handle_internal_command tools/perf/perf.c:364:8 #7 0x5649659440c4 in run_argv tools/perf/perf.c:408:2 #8 0x564965942e41 in main tools/perf/perf.c:538:3
0x6020000015f0 is located 0 bytes inside of 1-byte region [0x6020000015f0,0x6020000015f1) freed by thread T0 here: #0 0x564965929da3 in realloc third_party/llvm/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3 #1 0x564965c0f55e in mem2node__init tools/perf/util/mem2node.c:97:16 #2 0x564965a08956 in perf_c2c__report tools/perf/builtin-c2c.c:2803:8 #3 0x564965a0616a in cmd_c2c tools/perf/builtin-c2c.c:2989:10 #4 0x564965944348 in run_builtin tools/perf/perf.c:312:11 #5 0x564965943235 in handle_internal_command tools/perf/perf.c:364:8 #6 0x5649659440c4 in run_argv tools/perf/perf.c:408:2 #7 0x564965942e41 in main tools/perf/perf.c:538:3
previously allocated by thread T0 here: #0 0x564965929c42 in calloc third_party/llvm/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3 #1 0x5649659e9220 in zalloc tools/lib/zalloc.c:8:9 #2 0x564965c0f32d in mem2node__init tools/perf/util/mem2node.c:61:12 #3 0x564965a08956 in perf_c2c__report tools/perf/builtin-c2c.c:2803:8 #4 0x564965a0616a in cmd_c2c tools/perf/builtin-c2c.c:2989:10 #5 0x564965944348 in run_builtin tools/perf/perf.c:312:11 #6 0x564965943235 in handle_internal_command tools/perf/perf.c:364:8 #7 0x5649659440c4 in run_argv tools/perf/perf.c:408:2 #8 0x564965942e41 in main tools/perf/perf.c:538:3
v2: add a WARN_ON_ONCE when the free condition arises.
Signed-off-by: Ian Rogers irogers@google.com Acked-by: Jiri Olsa jolsa@redhat.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Mark Rutland mark.rutland@arm.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Stephane Eranian eranian@google.com Cc: clang-built-linux@googlegroups.com Link: http://lore.kernel.org/lkml/20200320182347.87675-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/mem2node.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/mem2node.c b/tools/perf/util/mem2node.c index c6fd81c025863..81c5a2e438b7d 100644 --- a/tools/perf/util/mem2node.c +++ b/tools/perf/util/mem2node.c @@ -1,5 +1,6 @@ #include <errno.h> #include <inttypes.h> +#include <asm/bug.h> #include <linux/bitmap.h> #include "mem2node.h" #include "util.h" @@ -92,7 +93,7 @@ int mem2node__init(struct mem2node *map, struct perf_env *env)
/* Cut unused entries, due to merging. */ tmp_entries = realloc(entries, sizeof(*entries) * j); - if (tmp_entries) + if (tmp_entries || WARN_ON_ONCE(j == 0)) entries = tmp_entries;
for (i = 0; i < j; i++) {