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 550912571A1 for ; Mon, 13 Oct 2025 11:47:54 +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=1760356074; cv=none; b=XONft5uib5kQUjNKmSh3VRLpXGu6BXa/ZDshjaKEUVP83MSUns6xHM1mjK9smlyd3G01wdfcgeWb3EG1VqfpRQ3loGUtqfTZGfwSNUy1tyTpCNTvVsp4wx8mNJDGF4G8XClAN5FqtVGfn6/+MkecZ+I1L1r0HwP0DBeA7KfRChU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760356074; c=relaxed/simple; bh=+uNp1AM0Ztr95Qh0o1alH9FDA5oZz4D9QKmH8WKkXA8=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=sMFciNZABI433Ktqh2pYIv7uo6mgmBptbu8UqAkmdgPZAFz+FhcqTleJd//DxiUtMJCwiHYSM0d2YkcuSTa7v0GhYIm2utvuMmyG7N4nDBWigTFT7DMsVdhHV2zOIJNHd9gOTAeFyYlxWXHHH88QFjGmolmCN9oo3xgfj/pLIxQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Eyy6Nvc/; 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="Eyy6Nvc/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CAF39C4CEF8; Mon, 13 Oct 2025 11:47:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760356074; bh=+uNp1AM0Ztr95Qh0o1alH9FDA5oZz4D9QKmH8WKkXA8=; h=Subject:To:Cc:From:Date:From; b=Eyy6Nvc/kxeF/ugfjYwRqfPakf+LE6u7S9tX2Q8Mgbz7TxnSsl4VeMGr2ReKvogzF WjTB1r7z4S9JFrIvalezjXppJRUP2EuqElLSslTfPAZLUv7PQNeHVcPLZph/qQK8fM sG0PnDIshxxuU+G86WHzXPXeh5xpJ2RCF/KIcSH4= Subject: FAILED: patch "[PATCH] PCI: endpoint: pci-epf-test: Add NULL check for DMA channels" failed to apply to 5.15-stable tree To: shinichiro.kawasaki@wdc.com,dlemoal@kernel.org,kwilczynski@kernel.org,mani@kernel.org Cc: From: Date: Mon, 13 Oct 2025 13:47:41 +0200 Message-ID: <2025101341-hurler-salute-f4f9@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 85afa9ea122dd9d4a2ead104a951d318975dcd25 # git commit -s git send-email --to '' --in-reply-to '2025101341-hurler-salute-f4f9@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 85afa9ea122dd9d4a2ead104a951d318975dcd25 Mon Sep 17 00:00:00 2001 From: Shin'ichiro Kawasaki Date: Tue, 16 Sep 2025 11:57:56 +0900 Subject: [PATCH] PCI: endpoint: pci-epf-test: Add NULL check for DMA channels before release MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index 09e1b8b46b55..31617772ad51 100644 --- 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(struct pci_epf_test *epf_test) 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,