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authorArnaldo Carvalho de Melo <acme@redhat.com>2017-01-03 15:19:21 -0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-08-06 18:59:48 -0700
commitddc0ec3be8077a689e0136c873519bf851a741e6 (patch)
treedea124e8aea5106d6417735e61d34f18e12e392c
parentd8086c3bd3a556e7598c93e5d303f771356adf9f (diff)
perf symbols: Robustify reading of build-id from sysfs
[ Upstream commit 7934c98a6e04028eb34c1293bfb5a6b0ab630b66 ] Markus reported that perf segfaults when reading /sys/kernel/notes from a kernel linked with GNU gold, due to what looks like a gold bug, so do some bounds checking to avoid crashing in that case. Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Report-Link: http://lkml.kernel.org/r/20161219161821.GA294@x4 Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-ryhgs6a6jxvz207j2636w31c@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--tools/perf/util/symbol-elf.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 99400b0e8f2a..adbc6c02c3aa 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -537,6 +537,12 @@ int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
break;
} else {
int n = namesz + descsz;
+
+ if (n > (int)sizeof(bf)) {
+ n = sizeof(bf);
+ pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
+ __func__, filename, nhdr.n_namesz, nhdr.n_descsz);
+ }
if (read(fd, bf, n) != n)
break;
}