Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 9F2903F7A9B; Mon, 17 Aug 2026 14:32:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786977152; cv=none; b=O4/tWX4t8A7f7cb3uSZmADiEJmRjp6MazD24suQFY2e391hV6Je3vuibLIuILE+xs8ESxJSpDr6AqtUsC7BJAEyBtnyOs6fpvHtoDMycepMgr3NxIoKRHh8dNgqOFnDF4wfi9trDmNk6lqs3wZzq1Fa3u7S+iejLHIoA8UpVLcE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786977152; c=relaxed/simple; bh=dglPiEDTM8Jxm+FF85QHcpEv8TSMSg1BkpmgeYjqG98=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gHhG2iabt6cwwhbcuD4wjHW6eNY/2ewWNJ3Yb8NX0EKUz3hAnvuuWJ9WdvPBXY2lhMIAkbOmCMWlDg67K8SrcMDm7bisLapFk/YTyiJ1QX/YsWJd4WU0awK9AAd0mbc2mKXhlYn/DnIPsy/bFvEKwnIV9kiREzu5SyYobgdlVxc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=u/4vcB3W; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="u/4vcB3W" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DEFB61F00A3D; Mon, 17 Aug 2026 14:32:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786977151; bh=1oyhdItVFQzpYyE6wT+My9qUtm5zb51Eo7vFtkI2uiM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=u/4vcB3Wv4C3+J2mleSKtDKhJVQUPnWSZxQcMJORlt5sF0pwyakTPnxLIBLLI2wlX +cQIBv8MsyFC3OrooDD/Nck6ITwejKOK4qFYJaGsI4x7JxDyo2opxRYj5VTDNHP0y/ dXLUfBRZzoojXHjFAZyk41BznQXRexDPVtt7yjlM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sashiko , Steven Rostedt Subject: [PATCH 5.15 191/456] tracing: Fix mmiotrace possible NULL dereferencing of hiter->dev Date: Mon, 17 Aug 2026 15:29:41 +0200 Message-ID: <20260817132547.589867338@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132539.792407575@linuxfoundation.org> References: <20260817132539.792407575@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Rostedt commit 144f29e85702234b23d2a62abf723e6a17eb5427 upstream. If the mmio_pipe_open() fails to find a PCI device, the hiter->dev will be assigned to NULL. The mmiotrace read() function dereferences the hiter->dev if hiter exists. Change the test of the read to not only check hiter being NULL, but also the hiter->dev before dereferencing it. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260721211143.36dbd559@gandalf.local.home Fixes: f984b51e0779 ("ftrace: add mmiotrace plugin") Reported-by: Sashiko Link: https://sashiko.dev/#/patchset/20260715143604.14481-1-gaikwad.dcg%40gmail.com Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_mmiotrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -146,7 +146,7 @@ static ssize_t mmio_read(struct trace_it goto print_out; } - if (!hiter) + if (!hiter || !hiter->dev) return 0; mmio_print_pcidev(s, hiter->dev);