From: Arnaldo Carvalho de Melo <a...@redhat.com> [ 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 <mar...@trippelsdorf.de> Report-Link: http://lkml.kernel.org/r/20161219161821.GA294@x4 Cc: Adrian Hunter <adrian.hun...@intel.com> Cc: David Ahern <dsah...@gmail.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Wang Nan <wangn...@huawei.com> Link: http://lkml.kernel.org/n/tip-ryhgs6a6jxvz207j2636w...@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> Signed-off-by: Sasha Levin <alexander.le...@verizon.com> --- tools/perf/util/symbol-elf.c | 6 ++++++ 1 file changed, 6 insertions(+) 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; } -- 2.11.0
