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 EA3CC330D3E; Wed, 17 Sep 2025 12:52:38 +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=1758113559; cv=none; b=DMwmhmIyrU0+wro88X3BC+2rPrwfLj1wa+DP2RoRpD8cFhy20AXCMKZ+VM5WsQwh8Mlnwbmzz4ej5yEXI5J2EllRPJ3VnYRApsGyFdwY8syiBidlMt8JXEPSc3FLpEeVKsyxmfvjnjWqqldAbWAbiCQob7pwzk+6a5LwCddhsxA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758113559; c=relaxed/simple; bh=TDQ4H1FhoYaW2LkNoP5F+gj8HNCKdjqBXOV4Tis2ZeQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=E+kMqqzVD0IQ+eQqR4jTDl3aJe+QNPgYv25k8y7q8+s0nkbkFwTabS768/dwOs99O5Lbv/HkSTQk3RBL41hRdrhweHR+CyJmyfCSatYq/6p0tvRWAP3ssXwHicAhkyZkQs1vlVcZOAyuMTXTT1V1Xfi8iw2N+NEJS9RbywILwWI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vM9s5PY3; 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="vM9s5PY3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A00CC4CEF0; Wed, 17 Sep 2025 12:52:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1758113558; bh=TDQ4H1FhoYaW2LkNoP5F+gj8HNCKdjqBXOV4Tis2ZeQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vM9s5PY35gPTHuST5zo4rEiNs57AlJ9tf6POHoHj9l2ucEg6lBo1VSq3Y71zIZigC OA8kH7Ce3LAu4zDRtLbOi3q/bkgIeVSAdD0/MpZplx7n4wGrv6yseZz8QGzXXIDxPs jC9JWE44CnWzRVtsEq7lpiPSwVqFOadYTnqfr8qM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yi Sun , Shuai Xue , Dave Jiang , Vinicius Costa Gomes , Vinod Koul , Sasha Levin Subject: [PATCH 6.12 121/140] dmaengine: idxd: Remove improper idxd_free Date: Wed, 17 Sep 2025 14:34:53 +0200 Message-ID: <20250917123347.266177023@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250917123344.315037637@linuxfoundation.org> References: <20250917123344.315037637@linuxfoundation.org> User-Agent: quilt/0.68 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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yi Sun [ Upstream commit f41c538881eec4dcf5961a242097d447f848cda6 ] The call to idxd_free() introduces a duplicate put_device() leading to a reference count underflow: refcount_t: underflow; use-after-free. WARNING: CPU: 15 PID: 4428 at lib/refcount.c:28 refcount_warn_saturate+0xbe/0x110 ... Call Trace: idxd_remove+0xe4/0x120 [idxd] pci_device_remove+0x3f/0xb0 device_release_driver_internal+0x197/0x200 driver_detach+0x48/0x90 bus_remove_driver+0x74/0xf0 pci_unregister_driver+0x2e/0xb0 idxd_exit_module+0x34/0x7a0 [idxd] __do_sys_delete_module.constprop.0+0x183/0x280 do_syscall_64+0x54/0xd70 entry_SYSCALL_64_after_hwframe+0x76/0x7e The idxd_unregister_devices() which is invoked at the very beginning of idxd_remove(), already takes care of the necessary put_device() through the following call path: idxd_unregister_devices() -> device_unregister() -> put_device() In addition, when CONFIG_DEBUG_KOBJECT_RELEASE is enabled, put_device() may trigger asynchronous cleanup via schedule_delayed_work(). If idxd_free() is called immediately after, it can result in a use-after-free. Remove the improper idxd_free() to avoid both the refcount underflow and potential memory corruption during module unload. Fixes: d5449ff1b04d ("dmaengine: idxd: Add missing idxd cleanup to fix memory leak in remove call") Signed-off-by: Yi Sun Tested-by: Shuai Xue Reviewed-by: Dave Jiang Acked-by: Vinicius Costa Gomes Link: https://lore.kernel.org/r/20250729150313.1934101-2-yi.sun@intel.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/dma/idxd/init.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c index 18997f80bdc97..d6308adc4eeb9 100644 --- a/drivers/dma/idxd/init.c +++ b/drivers/dma/idxd/init.c @@ -921,7 +921,6 @@ static void idxd_remove(struct pci_dev *pdev) idxd_cleanup(idxd); pci_iounmap(pdev, idxd->reg_base); put_device(idxd_confdev(idxd)); - idxd_free(idxd); pci_disable_device(pdev); } -- 2.51.0