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 F0D8D286AC; Thu, 16 Apr 2026 00:14:42 +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=1776298483; cv=none; b=Rru3tMh5wJGgXYn4oKpNavfpXquVQmqfjbsjU0K9DyFdT8tTIT6/LccfKEiSdjtly/7m2DTaSdP/aZNsgeYwDwYqGAvFzyPPP1vEc3zhDWoZDIJu9L2DzYp8hNdKWYk/Kr+7IA3ehbyMv+XHSoOKpvl+fIq0TCYvK2T/nZOY6hw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776298483; c=relaxed/simple; bh=H6liez7WESmbfgSAy1NtmogDKAjTD1AhH+U1x5vV9kQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lvKMsutY9fvnMH0j/jRPuFRQtRHdAzrWIpiGOm5UtTCGsH5v0rQaDMpiJyjAm+fwCIRz9b2u/oHo69t7R5HnAo4CiLWzvKrahtbOKt7DQawa9wHS6wF3KvxwVQ7aB7aGqQ1SpaU3eEvbCZC2G8TWw8KHw9zZ3udw/Xp/4DTkKLU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MKxQ6lFG; 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="MKxQ6lFG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7261CC19424; Thu, 16 Apr 2026 00:14:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776298482; bh=H6liez7WESmbfgSAy1NtmogDKAjTD1AhH+U1x5vV9kQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MKxQ6lFGmnimHMvPanb0oddpjDqxWe1weKqjw1pMtrD+DU8YVs2AaRzUZEm9zpGAI lIAA4p8yU3gIJnwoABIJOGejLVn42/a8n1UVoA9ZNASF17deSqu0JsTm/tnvKtJKTA H52kjoimrVaTO1M40KESN9Hloo/kJnxkYu5h+MSFxAgq+zOSFMPoIq+3yVFsTNbF2G HXHYGnmCSHI6X3QQa9KcylnEUfaxsfrIFp0t/g+537cR+Gi4lCovi5D4cHnrFmFn/V RP+XaDYRCu3V1md3b9FRLms9JF4DccGMOPSDOvNt2+25rWAnQq+qrpmPqYbxWRlINy Ip2FX03WCCYmQ== 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 Subject: [PATCH 2/5] perf header: Validate string length before allocating in do_read_string() Date: Wed, 15 Apr 2026 21:14:21 -0300 Message-ID: <20260416001424.362797-3-acme@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260416001424.362797-1-acme@kernel.org> References: <20260416001424.362797-1-acme@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Arnaldo Carvalho de Melo do_read_string() reads a u32 length from the file and immediately allocates that many bytes. A crafted perf.data could claim a huge string length, triggering a large allocation that would only be freed moments later when __do_read() rejects the read against the section bounds. Check len against the remaining section size before the malloc(). Cc: Ian Rogers Assisted-by: Claude Code:claude-opus-4-6 Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/header.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 13bbf8df15f66cab..c27ed90727ea6629 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -269,6 +269,9 @@ static char *do_read_string(struct feat_fd *ff) if (do_read_u32(ff, &len)) return NULL; + if (len > ff->size - ff->offset) + return NULL; + buf = malloc(len); if (!buf) return NULL; -- 2.53.0