From: Ian Rogers <irogers@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com
Cc: Stephane Eranian <eranian@google.com>, Ian Rogers <irogers@google.com>
Subject: [PATCH v2] perf mem2node: avoid double free related to realloc
Date: Fri, 20 Mar 2020 11:23:47 -0700 [thread overview]
Message-ID: <20200320182347.87675-1-irogers@google.com> (raw)
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>
---
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 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++) {
--
2.25.1.696.g5e7596f4ac-goog
next reply other threads:[~2020-03-20 18:23 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-20 18:23 Ian Rogers [this message]
2020-04-29 17:40 ` [PATCH v2] perf mem2node: avoid double free related to realloc Ian Rogers
2020-04-29 17:45 ` Arnaldo Carvalho de Melo
2020-04-30 8:15 ` Jiri Olsa
2020-04-30 13:23 ` Arnaldo Carvalho de Melo
2020-05-08 13:04 ` [tip: perf/core] perf mem2node: Avoid " tip-bot2 for Ian Rogers
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