| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 80/91] perf symbols: Robustify reading of build-id from sysfs | Date | Fri, 4 Aug 2017 16:16:16 -0700 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Arnaldo Carvalho de Melo <acme@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 <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> --- tools/perf/util/symbol-elf.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -488,6 +488,12 @@ int sysfs__read_build_id(const char *fil 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; }
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