perf symbols: Fix return incorrect build_id size in elf_read_build_id()

In elf_read_build_id(), if gnu build_id is found, should return the size of
the actually copied data. If descsz is greater thanBuild_ID_SIZE,
write_buildid data access may occur.

Fixes: be96ea8ffa ("perf symbols: Fix issue with binaries using 16-bytes buildids (v2)")
Reported-by: Will Ochowicz <Will.Ochowicz@genusplc.com>
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Tested-by: Will Ochowicz <Will.Ochowicz@genusplc.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/lkml/CWLP265MB49702F7BA3D6D8F13E4B1A719C649@CWLP265MB4970.GBRP265.PROD.OUTLOOK.COM/T/
Link: https://lore.kernel.org/r/20230427012841.231729-1-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Yang Jihong 2023-04-27 01:28:41 +00:00 committed by Arnaldo Carvalho de Melo
parent 6a7b57d85f
commit 1511e4696a

View File

@ -886,7 +886,7 @@ static int elf_read_build_id(Elf *elf, void *bf, size_t size)
size_t sz = min(size, descsz);
memcpy(bf, ptr, sz);
memset(bf + sz, 0, size - sz);
err = descsz;
err = sz;
break;
}
}