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| author | Matt Fleming <matt@readmodwrite.com> | 2024-08-15 15:22:12 +0100 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2024-08-15 11:50:13 -0300 |
| commit | ac01c8c4246546fd8340a232f3ada1921dc0ee48 (patch) | |
| tree | a991480ca3d461ecb830966d9c2422a69d7ebc06 | |
| parent | 27ac597c0e2f596f53963db4a2cf53cd84657cda (diff) | |
| download | lwn-ac01c8c4246546fd8340a232f3ada1921dc0ee48.tar.gz lwn-ac01c8c4246546fd8340a232f3ada1921dc0ee48.zip | |
perf hist: Update hist symbol when updating maps
AddressSanitizer found a use-after-free bug in the symbol code which
manifested as 'perf top' segfaulting.
==1238389==ERROR: AddressSanitizer: heap-use-after-free on address 0x60b00c48844b at pc 0x5650d8035961 bp 0x7f751aaecc90 sp 0x7f751aaecc80
READ of size 1 at 0x60b00c48844b thread T193
#0 0x5650d8035960 in _sort__sym_cmp util/sort.c:310
#1 0x5650d8043744 in hist_entry__cmp util/hist.c:1286
#2 0x5650d8043951 in hists__findnew_entry util/hist.c:614
#3 0x5650d804568f in __hists__add_entry util/hist.c:754
#4 0x5650d8045bf9 in hists__add_entry util/hist.c:772
#5 0x5650d8045df1 in iter_add_single_normal_entry util/hist.c:997
#6 0x5650d8043326 in hist_entry_iter__add util/hist.c:1242
#7 0x5650d7ceeefe in perf_event__process_sample /home/matt/src/linux/tools/perf/builtin-top.c:845
#8 0x5650d7ceeefe in deliver_event /home/matt/src/linux/tools/perf/builtin-top.c:1208
#9 0x5650d7fdb51b in do_flush util/ordered-events.c:245
#10 0x5650d7fdb51b in __ordered_events__flush util/ordered-events.c:324
#11 0x5650d7ced743 in process_thread /home/matt/src/linux/tools/perf/builtin-top.c:1120
#12 0x7f757ef1f133 in start_thread nptl/pthread_create.c:442
#13 0x7f757ef9f7db in clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
When updating hist maps it's also necessary to update the hist symbol
reference because the old one gets freed in map__put().
While this bug was probably introduced with 5c24b67aae72f54c ("perf
tools: Replace map->referenced & maps->removed_maps with map->refcnt"),
the symbol objects were leaked until c087e9480cf33672 ("perf machine:
Fix refcount usage when processing PERF_RECORD_KSYMBOL") was merged so
the bug was masked.
Fixes: c087e9480cf33672 ("perf machine: Fix refcount usage when processing PERF_RECORD_KSYMBOL")
Reported-by: Yunzhao Li <yunzhao@cloudflare.com>
Signed-off-by: Matt Fleming (Cloudflare) <matt@readmodwrite.com>
Cc: Ian Rogers <irogers@google.com>
Cc: kernel-team@cloudflare.com
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: stable@vger.kernel.org # v5.13+
Link: https://lore.kernel.org/r/20240815142212.3834625-1-matt@readmodwrite.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/util/hist.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c index 0f554febf9a1..0f9ce2ee2c31 100644 --- a/tools/perf/util/hist.c +++ b/tools/perf/util/hist.c @@ -639,6 +639,11 @@ static struct hist_entry *hists__findnew_entry(struct hists *hists, * the history counter to increment. */ if (he->ms.map != entry->ms.map) { + if (he->ms.sym) { + u64 addr = he->ms.sym->start; + he->ms.sym = map__find_symbol(entry->ms.map, addr); + } + map__put(he->ms.map); he->ms.map = map__get(entry->ms.map); } |