This is a note to let you know that I've just added the patch titled perf event: Check ref_reloc_sym before using it to the 4.9-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-event-check-ref_reloc_sym-before-using-it.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From e9a6882f267a8105461066e3ea6b4b6b9be1b807 Mon Sep 17 00:00:00 2001 From: Igor Lubashev <ilubashe@xxxxxxxxxx> Date: Mon, 26 Aug 2019 21:39:12 -0400 Subject: perf event: Check ref_reloc_sym before using it From: Igor Lubashev <ilubashe@xxxxxxxxxx> commit e9a6882f267a8105461066e3ea6b4b6b9be1b807 upstream. Check for ref_reloc_sym before using it instead of checking symbol_conf.kptr_restrict and relying solely on that check. Reported-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> Signed-off-by: Igor Lubashev <ilubashe@xxxxxxxxxx> Tested-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx> Cc: James Morris <jmorris@xxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Suzuki Poulouse <suzuki.poulose@xxxxxxx> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Link: http://lkml.kernel.org/r/1566869956-7154-2-git-send-email-ilubashe@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Alexander Dahl <ada@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/perf/util/event.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -682,11 +682,13 @@ int perf_event__synthesize_kernel_mmap(s int err; union perf_event *event; - if (symbol_conf.kptr_restrict) - return -1; if (map == NULL) return -1; + kmap = map__kmap(map); + if (!kmap->ref_reloc_sym) + return -1; + /* * We should get this from /sys/kernel/sections/.text, but till that is * available use this, and after it is use this as a fallback for older @@ -710,7 +712,6 @@ int perf_event__synthesize_kernel_mmap(s event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL; } - kmap = map__kmap(map); size = snprintf(event->mmap.filename, sizeof(event->mmap.filename), "%s%s", mmap_name, kmap->ref_reloc_sym->name) + 1; size = PERF_ALIGN(size, sizeof(u64)); Patches currently in stable-queue which might be from ilubashe@xxxxxxxxxx are queue-4.9/perf-event-check-ref_reloc_sym-before-using-it.patch