From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794357644; b=PqJAXGLv7l7ZzZrIfaW/mMDNctwNvgFa6T2oG8CkDoymL5TuYfdFqSklGmmQLSWQfsOX iWUnP4nfTIINe5k8lSKpan9recJxuqqE4CSKq2Oa6pzPZPegZQaxijR3s9e5Xlh3B97OD HcrFPdVbrKSYoNC75+keDLXZKFagoXshkFGWmlyN7hZy4EiIEqY+g2rCU77XcVgMs4lpK lGuY0UiRQ3Tds7PjGwZEoH1f7eImR7KQipEcgPFtp/zN3qwhOhVHHDxgHCuKf3GqMNkrh OqpmlhEeNYjly6J68Ht2TzzoDX3iS1I8l74A2VmkwJbzhzcHn5k6PHL5kwZAqYahQzw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794357644; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=1M5ZgFz6KcfVMsA0N5dQFTgZxJVszqvfsrrFeCjl2UM=; b=4UGod7DIQeYNi+I1/aPV8+XVZK79aKTR8wrwni91jWcRr0YXWTLei/IVmG4ChC6horat ENY/ERayO/YcnUpomGDCD7yfBH6lc23zcyU3rZsb2LGwbQkvd+fv/XQfjFKaLivHxv5Ue 6jS+8cUPUHx9fe1zM2YgdsD5c8vMIIfKSH8HwGs9PyVGqAT/Ts8xW0NrxdwAA8Qu9Vo2q yVqrYAH8cZXaHCy0QvM5Zj7f8LUYhT9GcZa1cU7+tlizurQlBHmq3sZH8DekhATq7+JY0 +5b7fKAd6VK5k8Qu8VvDXftlBM8B8kbHAdQEr2AXd9pb/X4zZPgc9b6H2WLhauVpO1w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=lbsfAd2V; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6E03E606A31C for ; Wed, 11 Nov 2026 00:40:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=lbsfAd2V Received: by smtp.kernel.org (Postfix) with ESMTPSA id 87C3C1F0089F; Wed, 11 Nov 2026 00:40:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794357644; bh=1M5ZgFz6KcfVMsA0N5dQFTgZxJVszqvfsrrFeCjl2UM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lbsfAd2VM2+siJvb9Gr/s/D4cGO3JLjafqWR9w5Z8jgG12fV/aYjUZpJrpnUfQSaT oHS5sOki5VEJHlvyj6aBgw5o+swqGRCVtGzls160INYqt/RNRJXMlcWycBsXVms4DR iv1NE6XZ4G11Ex3+zUnO6pQxF6ILWh8RsrO4C0BYTVpGO8Zvj4fbBNSdfIVQVNXJNY EOaX9xsVlTXsOmfA5hnf7M/0hjzttsiY+8CGIBGKLxBvITo7utFRTLoxX1R0hvS/U+ XTOZzvKoIu+BlEMw77WPfAOdFkqxfDMrKPF71D33+2xVkq6MKJtEA8C3+JuS4bSmBk zEUb/BWs41M0g== From: Sasha Levin To: stable@vger.kernel.org Cc: Wentao Liang , Juergen Gross , Sasha Levin Subject: [PATCH 6.1.y] xen/gntdev: Fix gntdev_dmabuf ref leak in dmabuf_exp_wait_released() Date: Tue, 10 Nov 2026 19:40:42 -0500 Message-ID: <20261111003822.292437-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261107054621-failed-6.1-6f165abe2b40@kernel.org> References: <20261107054621-failed-6.1-6f165abe2b40@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Wentao Liang [ Upstream commit 6f165abe2b40ede71c98956cd74cd17c18505e75 ] dmabuf_exp_wait_released() takes a reference on the exported gntdev_dmabuf with dmabuf_exp_wait_obj_get_dmabuf() and passes it to dmabuf_exp_wait_obj_new(), which drops that reference after adding the wait object to the wait list. When the wait object allocation fails, dmabuf_exp_wait_obj_new() returns ERR_PTR(-ENOMEM) early and the reference is never dropped, leaking a reference to the exported gntdev_dmabuf. Drop the reference on the allocation failure path so the reference is consumed whether the wait object is created or not. Fixes: 932d6562179e ("xen/gntdev: Add initial support for dma-buf UAPI") Cc: stable@vger.kernel.org Signed-off-by: Wentao Liang Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Message-ID: <20260916170956.2086505-1-vulab@iscas.ac.cn> [ sashal: adjusted allocation context from kzalloc_obj(*obj) to kzalloc(sizeof(*obj), GFP_KERNEL) ] Signed-off-by: Sasha Levin --- drivers/xen/gntdev-dmabuf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/xen/gntdev-dmabuf.c b/drivers/xen/gntdev-dmabuf.c index 7df26330af424..8dd95385d3e46 100644 --- a/drivers/xen/gntdev-dmabuf.c +++ b/drivers/xen/gntdev-dmabuf.c @@ -96,8 +96,10 @@ dmabuf_exp_wait_obj_new(struct gntdev_dmabuf_priv *priv, struct gntdev_dmabuf_wait_obj *obj; obj = kzalloc(sizeof(*obj), GFP_KERNEL); - if (!obj) + if (!obj) { + kref_put(&gntdev_dmabuf->u.exp.refcount, dmabuf_exp_release); return ERR_PTR(-ENOMEM); + } init_completion(&obj->completion); obj->gntdev_dmabuf = gntdev_dmabuf; -- 2.53.0