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authorIan Rogers <irogers@google.com>2020-03-20 11:23:47 -0700
committerArnaldo Carvalho de Melo <acme@redhat.com>2020-05-05 16:35:30 -0300
commit266150c94c69429cf6d18e130237224a047f5061 (patch)
tree2d8fa2efde8f5315893c8274e454ee3a78d22ad9 /tools/perf/util
parentefc0cdc9ed5e6cfb060ff7b77834cad9d3c97d1d (diff)
perf mem2node: Avoid double free related to realloc
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>
Diffstat (limited to 'tools/perf/util')
-rw-r--r--tools/perf/util/mem2node.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/tools/perf/util/mem2node.c b/tools/perf/util/mem2node.c
index 797d86a1ab09..c84f5841c7ab 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 <linux/kernel.h>
#include <linux/zalloc.h>
@@ -95,7 +96,7 @@ 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++) {