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 3BF99221555; Mon, 13 Oct 2025 15:45:15 +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=1760370315; cv=none; b=eDejpb21ekYQPcLmRSdPpbJPbE+NIPLZElDFhAqqtneP3CFtCcbvykJxFQ+OwuAlRPIRikhojfNRI98cT7AiSexuPl7udpIyOrhsV366bNw5f3Y+4S3jS/P3g++dS4txS6kRvM0mU91wIPO2w7nKqmUKRkM12o97TDoAohwq8bU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760370315; c=relaxed/simple; bh=dNQHuBcm9RmQW7k+xWyuYAtQZT1pLWPQRfeEqBMBVFQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=H5QWwtRmFgFz7EB1wFSSaxEgrk1SAan7D0+s3EnLaMqdZJdbr3e2+RV6JZ3iOfMqIV9BhojrUIIn8VycFC6Zbi00MlT1fI5dqHzij5ogrE4bfrhPFlQb2xsS3NWTlAAUnA258x/idneYYcswV+ketnl0YCHy732CWhrcHL+Akmg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dRDWO/KH; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="dRDWO/KH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3971C4CEE7; Mon, 13 Oct 2025 15:45:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760370315; bh=dNQHuBcm9RmQW7k+xWyuYAtQZT1pLWPQRfeEqBMBVFQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dRDWO/KH7B67kelcRizqQbYe4qnVQq39SzYR0VFPZxlu7XNEWDcz/PfuCVe6LFmqr 6bSQJ+DRhyH296d9BYWt3EKwlD9wPHkWEZHn14u8DD0lWfIqMkuXjZ643tZlQXgtVd P1d+EnhO6ORqSxT3MRSyd55H+Xh0Jz0hPbApB7pc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shinichiro Kawasaki , Manivannan Sadhasivam , Damien Le Moal , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= Subject: [PATCH 6.17 552/563] PCI: endpoint: pci-epf-test: Add NULL check for DMA channels before release Date: Mon, 13 Oct 2025 16:46:53 +0200 Message-ID: <20251013144431.300876989@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251013144411.274874080@linuxfoundation.org> References: <20251013144411.274874080@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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shin'ichiro Kawasaki commit 85afa9ea122dd9d4a2ead104a951d318975dcd25 upstream. The fields dma_chan_tx and dma_chan_rx of the struct pci_epf_test can be NULL even after EPF initialization. Then it is prudent to check that they have non-NULL values before releasing the channels. Add the checks in pci_epf_test_clean_dma_chan(). Without the checks, NULL pointer dereferences happen and they can lead to a kernel panic in some cases: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050 Call trace: dma_release_channel+0x2c/0x120 (P) pci_epf_test_epc_deinit+0x94/0xc0 [pci_epf_test] pci_epc_deinit_notify+0x74/0xc0 tegra_pcie_ep_pex_rst_irq+0x250/0x5d8 irq_thread_fn+0x34/0xb8 irq_thread+0x18c/0x2e8 kthread+0x14c/0x210 ret_from_fork+0x10/0x20 Fixes: 8353813c88ef ("PCI: endpoint: Enable DMA tests for endpoints with DMA capabilities") Fixes: 5ebf3fc59bd2 ("PCI: endpoint: functions/pci-epf-test: Add DMA support to transfer data") Signed-off-by: Shin'ichiro Kawasaki [mani: trimmed the stack trace] Signed-off-by: Manivannan Sadhasivam Reviewed-by: Damien Le Moal Reviewed-by: Krzysztof Wilczyński Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20250916025756.34807-1-shinichiro.kawasaki@wdc.com Signed-off-by: Greg Kroah-Hartman --- drivers/pci/endpoint/functions/pci-epf-test.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -301,15 +301,20 @@ static void pci_epf_test_clean_dma_chan( if (!epf_test->dma_supported) return; - dma_release_channel(epf_test->dma_chan_tx); - if (epf_test->dma_chan_tx == epf_test->dma_chan_rx) { + if (epf_test->dma_chan_tx) { + dma_release_channel(epf_test->dma_chan_tx); + if (epf_test->dma_chan_tx == epf_test->dma_chan_rx) { + epf_test->dma_chan_tx = NULL; + epf_test->dma_chan_rx = NULL; + return; + } epf_test->dma_chan_tx = NULL; - epf_test->dma_chan_rx = NULL; - return; } - dma_release_channel(epf_test->dma_chan_rx); - epf_test->dma_chan_rx = NULL; + if (epf_test->dma_chan_rx) { + dma_release_channel(epf_test->dma_chan_rx); + epf_test->dma_chan_rx = NULL; + } } static void pci_epf_test_print_rate(struct pci_epf_test *epf_test,