From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5C833282F25; Sun, 10 May 2026 03:35:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778384105; cv=none; b=W3+zbOs9iQiXyCpaR+BSqnAsZKbbETJnR3HlzUYDrlsxqv6svTZ4iam1vQMyOhlkc/dd/vgX/Aj1jxL8zXsfbK6K1MTDc1da6fvhamx5XBHqxX1eEfkvqSQs1Fe/xkSfrTZvRGwDqlYVVm3P3z2tXOEu5YSwCyrZ+heNk+LnQLw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778384105; c=relaxed/simple; bh=mDFHP9F/Ds48hmOA7Zbg0QqakHTLZzaOdmIMWu0gr2A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=DgPU9vByw2OjoYlpVv9rJDTLyr8jisVA4evwG2ZHKDXZsOEoGBpbCnR3rMbFNZT6vi3Egg5AnrzliL3KXG3Ig2I+jhmdyyxOeODNOVAC3jK+MD+MJZudPimxuzab+1DJOKovdAEZxTF0BA6Rjy5rEs+Y0z+1ilvKM/ahX+uVstE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YNHLrTHs; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YNHLrTHs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82F61C2BCB8; Sun, 10 May 2026 03:35:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778384105; bh=mDFHP9F/Ds48hmOA7Zbg0QqakHTLZzaOdmIMWu0gr2A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YNHLrTHsr1p93aLUl8qHhJO9cMwPLIGBNmvJt8uGtRTu35mH7Wv+vvJaB1maqeSp4 uypO2SSNJDNXpqwrOdDzksT4SnJ6CLlr+YGmt6UwqZ1tQItYmdWU4lktXfhJkoqaeX thirlPtgd60RNDD003UKhBPprnwYlrw+4r0+xka5PHPkWlJXPbBCEQj03yU26ZAT9E eMyH2rjL3umew5PixpEuZJK4DvBQB6V5cC/7lpCrwRe6YlztxsN6B7XT71FBc6uwN8 bf7Oy3FifLmIhZ+Y6VWM+Qi+vluyzRXFUYUW27rcTTZvUSKKSUYnJQ/lXebuIrR4La cQ6q1hgs/t4Cw== From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Ingo Molnar , Thomas Gleixner , James Clark , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , sashiko-bot@kernel.org, "Claude Opus 4.6 (1M context)" Subject: [PATCH 06/28] perf session: Align auxtrace_info priv size before byte-swapping Date: Sun, 10 May 2026 00:33:57 -0300 Message-ID: <20260510033424.255812-7-acme@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260510033424.255812-1-acme@kernel.org> References: <20260510033424.255812-1-acme@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Arnaldo Carvalho de Melo perf_event__auxtrace_info_swap() passes the raw remainder of header.size to mem_bswap_64(), which swaps in 8-byte chunks. If the size is not a multiple of 8, the last iteration reads and writes 8 bytes from a shorter region, overrunning the event buffer by up to 7 bytes. Round down to a u64 boundary — priv[] is a u64 array, so any unaligned tail is padding that doesn't need swapping. Also fix swap_sample_id_all() which had the same issue — replace BUG_ON(size % sizeof(u64)) with rounding down, since crafted events may have unaligned trailing data. Note: the strlen calls in string-field swap handlers (comm, mmap, mmap2, cgroup) are replaced with bounded strnlen by the next patch in this series ("perf session: Add validated swap infrastructure with null-termination checks"). Reported-by: sashiko-bot@kernel.org # Running on a local machine Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Assisted-by: Claude Opus 4.6 (1M context) Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/session.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 20b70d6fb7cc8ed4..b55c5168ee9f4aae 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -276,10 +276,16 @@ void perf_session__delete(struct perf_session *session) static void swap_sample_id_all(union perf_event *event, void *data) { void *end = (void *) event + event->header.size; - int size = end - data; + int size; - BUG_ON(size % sizeof(u64)); - mem_bswap_64(data, size); + if (data >= end) + return; + + size = end - data; + /* Only swap complete 8-byte elements */ + size &= ~(int)(sizeof(u64) - 1); + if (size > 0) + mem_bswap_64(data, size); } static void perf_event__all64_swap(union perf_event *event, @@ -585,6 +591,8 @@ static void perf_event__auxtrace_info_swap(union perf_event *event, size = event->header.size; size -= (void *)&event->auxtrace_info.priv - (void *)event; + /* priv[] is a u64 array; only swap complete 8-byte elements */ + size &= ~(size_t)(sizeof(u64) - 1); mem_bswap_64(event->auxtrace_info.priv, size); } -- 2.54.0