From nobody Mon Apr 6 09:15:26 2026 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (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 B4FC8277CB8 for ; Thu, 19 Mar 2026 18:39:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773945544; cv=none; b=gA1Ct9vVwcG1SlH5LRusvqLceyCvNLGfxA/U74GgA7kya0pGXmtMPPB+SDFwzQ9VPRbsHHSHc59ilZPPhOw72sqOfQXAI7IpYfAGOTJCgjCdeUTgXqA+xsneb1A4TYMbBzAflj9o8yiIHg6QChpJC1ZChEvEbfC2kKjIPW5kUs8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773945544; c=relaxed/simple; bh=vhQEfDoEfpNzFcXCQIuYkH3ah3+3jrEC9vhNPcP95bk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=NWPNTU5xKBTewXi3CNXcfhDmRfBs9w/aKsOGLRZP+e5wo0C7m3DaARciVNAHjTtrVcVN/5Oi+65wYH7thlAtHkq6p8lR9PCIL7SbvIkR2LUWuGrYXjAmPfyozGHE7IQqAmyf7mCMdzDw20BTUtfiYpjauibH4sjPfMhQGDvS1e0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1w3IGg-0005IY-KH; Thu, 19 Mar 2026 19:38:50 +0100 Received: from moin.white.stw.pengutronix.de ([2a0a:edc0:0:b01:1d::7b] helo=bjornoya.blackshift.org) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1w3IGg-0017V2-0o; Thu, 19 Mar 2026 19:38:50 +0100 Received: from hardanger.blackshift.org (p4ffb2dc6.dip0.t-ipconnect.de [79.251.45.198]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519MLKEM768 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: mkl-all@blackshift.org) by smtp.blackshift.org (Postfix) with ESMTPSA id F3A8450891B; Thu, 19 Mar 2026 18:38:49 +0000 (UTC) From: Marc Kleine-Budde Date: Thu, 19 Mar 2026 19:38:12 +0100 Subject: [PATCH spi] spi: spi-fsl-lpspi: fix teardown order issue (UAF) 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: quoted-printable Message-Id: <20260319-spi-fsl-lpspi-fixes-v1-1-b433e435b2d8@pengutronix.de> X-B4-Tracking: v=1; b=H4sIAJNCvGkC/yWMTQ6CMBCFr0Le2kmg2BK9inEhZZQhBJsOGhLC3 R1h9773t0I5CyuuxYrMX1F5TwbVqUDsH9OLSTpjuNKFsq4upEnoqSONaVeysFLjfAzB17E5e9g yZd4DG95gNdwPUz/twHH+/2Hbfiy03Dt8AAAA X-Change-ID: 20260319-spi-fsl-lpspi-fixes-725c6653c745 To: Frank Li , Mark Brown , Gao Pan , Fugang Duan Cc: kernel@pengutronix.de, linux-spi@vger.kernel.org, imx@lists.linux.dev, linux-kernel@vger.kernel.org, Marc Kleine-Budde X-Mailer: b4 0.15-dev-5154a X-Developer-Signature: v=1; a=openpgp-sha256; l=2262; i=mkl@pengutronix.de; h=from:subject:message-id; bh=vhQEfDoEfpNzFcXCQIuYkH3ah3+3jrEC9vhNPcP95bk=; b=owGbwMvMwCV2xirl17qZay8xnlZLYsjc4zTtbOmZdIbjx4T3+mY0rYrL7CvpqMmtvSlf7Gr0z FPl3pTYjlIWBjEuBlkxRZalP04oCgQ6lPa+TJgEM4eVCWQIAxenAEykMYnhr4TMrsj7/wWPT9Jb n+bV+zjuaJt2d2S7YM4G7f8L3jKc0mVkmLqwYE9PZojnYqO8ORLpR3ZMcF/ZKZVynil1LreolYE DDwA= X-Developer-Key: i=mkl@pengutronix.de; a=openpgp; fpr=C1400BA0B3989E6FBC7D5B5C2B5EE211C58AEA54 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org There is a teardown order issue in the driver. The SPI controller is registered using devm_spi_register_controller(), which delays unregistration of the SPI controller until after the fsl_lpspi_remove() function returns. As the fsl_lpspi_remove() function synchronously tears down the DMA channels, a running SPI transfer triggers the following NULL pointer dereference due to use after free: | fsl_lpspi 42550000.spi: I/O Error in DMA RX | Unable to handle kernel NULL pointer dereference at virtual address 00000= 00000000000 [...] | Call trace: | fsl_lpspi_dma_transfer+0x260/0x340 [spi_fsl_lpspi] | fsl_lpspi_transfer_one+0x198/0x448 [spi_fsl_lpspi] | spi_transfer_one_message+0x49c/0x7c8 | __spi_pump_transfer_message+0x120/0x420 | __spi_sync+0x2c4/0x520 | spi_sync+0x34/0x60 | spidev_message+0x20c/0x378 [spidev] | spidev_ioctl+0x398/0x750 [spidev] [...] Switch from devm_spi_register_controller() to spi_register_controller() in fsl_lpspi_probe() and add the corresponding spi_unregister_controller() in fsl_lpspi_remove(). Fixes: 5314987de5e5 ("spi: imx: add lpspi bus driver") Signed-off-by: Marc Kleine-Budde --- drivers/spi/spi-fsl-lpspi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c index b361c1bb3e43..45390e9b8cae 100644 --- a/drivers/spi/spi-fsl-lpspi.c +++ b/drivers/spi/spi-fsl-lpspi.c @@ -1009,7 +1009,7 @@ static int fsl_lpspi_probe(struct platform_device *pd= ev) enable_irq(irq); } =20 - ret =3D devm_spi_register_controller(&pdev->dev, controller); + ret =3D spi_register_controller(controller); if (ret < 0) { dev_err_probe(&pdev->dev, ret, "spi_register_controller error\n"); goto free_dma; @@ -1035,6 +1035,7 @@ static void fsl_lpspi_remove(struct platform_device *= pdev) struct fsl_lpspi_data *fsl_lpspi =3D spi_controller_get_devdata(controller); =20 + spi_unregister_controller(controller); fsl_lpspi_dma_exit(controller); =20 pm_runtime_dont_use_autosuspend(fsl_lpspi->dev); --- base-commit: 8c89a077ca796a2fe248c584e9d7e66cff0388c8 change-id: 20260319-spi-fsl-lpspi-fixes-725c6653c745 Best regards, -- =20 Marc Kleine-Budde