Messages in this thread | | | Date | Thu, 30 Apr 2020 10:15:41 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH v2] perf mem2node: avoid double free related to realloc |
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On Fri, Mar 20, 2020 at 11:23:47AM -0700, Ian Rogers wrote: > 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>
I overlooked v2 for this, sry
Acked-by: Jiri Olsa <jolsa@redhat.com>
thanks, jirka
> --- > 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 >
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