Patch "perf symbols: Robustify reading of build-id from sysfs" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

perf symbols: Robustify reading of build-id from sysfs

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
perf-symbols-robustify-reading-of-build-id-from-sysfs.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Arnaldo Carvalho de Melo <[email protected]>
Date: Tue, 3 Jan 2017 15:19:21 -0300
Subject: perf symbols: Robustify reading of build-id from sysfs

From: Arnaldo Carvalho de Melo <[email protected]>

[ 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.

Report-Link: http://lkml.kernel.org/r/20161219161821.GA294@x4

---
 tools/perf/util/symbol-elf.c |    6 ++++++
 1 file changed, 6 insertions(+)

@@ -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;
 		}

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/perf-intel-pt-ensure-never-to-set-last_ip-when-packet-count-is-zero.patch queue-4.4/perf-intel-pt-use-fup-always-when-scanning-for-an-ip.patch queue-4.4/perf-intel-pt-fix-last_ip-usage.patch queue-4.4/perf-tools-install-tools-lib-traceevent-plugins-with-install-bin.patch queue-4.4/perf-symbols-robustify-reading-of-build-id-from-sysfs.patch queue-4.4/tools-lib-traceevent-fix-prev-next_prio-for-deadline-tasks.patch queue-4.4/perf-intel-pt-fix-ip-compression.patch