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 93B01337EB9; Wed, 17 Sep 2025 12:44:42 +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=1758113082; cv=none; b=BLjhuppf3uwZJINrAQAnNT5rX060OLcwxo/W/bMNjyBpG34SVoaRIfQGbptPptgagg8vMYAziBYbHSRKhrNGDBS77o+Pk1+XahXBk4InaEiMnGtMfNEz7DHzY8D+cBPCQJCEx841y7yWm19pFd0Iy3FH3e4oD+jGK+yeKt6aIQM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758113082; c=relaxed/simple; bh=9G2Ox6d+qD6MVu2XzMM+0x64mWCwopSIAnLgCPdD5Ig=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GWoxhuYXXlEi6AZR5aSL2103G83pXvc+JKUS9cQerqhkqzk7rfpijFVx6nkRo5aik/12mQADQJLAxbHCzW3RTpeQzcVuPwq+m0qOYsqZzHnkTKzkjOq7PrgaXnzFNk+xFQuuFhA94O1tHLCl6uiggsRj/2VeuIFIhJeRgCHy0Z8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XHwdAicZ; 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="XHwdAicZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 103D4C4CEF0; Wed, 17 Sep 2025 12:44:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1758113082; bh=9G2Ox6d+qD6MVu2XzMM+0x64mWCwopSIAnLgCPdD5Ig=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XHwdAicZoGvQ8GvR+O1reZierfgXmu6zhiV8Mu1+puRRURWl9XwS3nZE5ldMlawDb McyGmUax/BQNdgDn1dFpkec7lK4fuzCN65Tis7Xy+g8nRYjHDg2vYkhiG2/+WY9Hpa feowzKuEYvGQfVcBNRM/ImFDwQydUgyqYWUc1NDc= 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 6.16 167/189] dmaengine: idxd: Remove improper idxd_free Date: Wed, 17 Sep 2025 14:34:37 +0200 Message-ID: <20250917123355.959623501@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250917123351.839989757@linuxfoundation.org> References: <20250917123351.839989757@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 6.16-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 80355d03004db..40cc9c070081f 100644 --- a/drivers/dma/idxd/init.c +++ b/drivers/dma/idxd/init.c @@ -1295,7 +1295,6 @@ 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