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=1794356767; b=qXcCIpbKl+Ze2y8+pfgf15+9eSH//ZcS7Z/VgaZYaYgmKawsEIj46vDs9GjVzEAWazpg FC2WqZoDwPTenm3q+eGH2sPSWxKIKKCUboObTBWbf/QT/HX8uvrZLGn15QnUhNo98yV7E UtUxM7S/Cr+b8l2iaWDAApzIMMB7Lu6Scx3Vm3O3ZIr8c+Bzr2EYOn2SXlFZKHymWV8tS yIsVc+mZOqW57ZaqmjxklxKCe1t+BOwj9RqFZt/XAopHCasDbsFwyqNKkPFecfeI7DINb goZ+X5QQl8t6z4pKwH0hEigDAf6xQevzFoCWmpJX4tkhOdl3DewFduTrR/fF+wgoRHg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794356767; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=PCjIWuc0VWpQkw6vOx/bUK+eJ+5cygz7dQMaILfWO/Q=; b=2CYyWv9w6HNco0JorjntqPGq35fQvku6K3yJs9FxmaokFHum7igZmh0raNjqAeq8023Q q5nZ+ZUDgPLsyNY9GVP0EM2nsAv5FQoTWZ68eRAJupuhkhvG4V39Yy9o9PHLRAOgiDMEp spZNa+gBeZWf+mGCJ5u6JecABlLCmkA4DzplX9agwexRoPtLEb3KSWX6G11hwQIqVqucL IlIYO6CL8VeelE1RNeIUp2kPLpDTYOMSU+UBX30U54bZa+AWhNr+IoL0SkOiOdDmT0kzl UQv95VaDBeLDBxHaPAlkGvJAtw2MmBDZh2zZeDR2o2fcK+pE65ehqODtmGlqO0xGcjA== 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=QzqPKv0y; 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 243BE606A333 for ; Wed, 11 Nov 2026 00:26:07 +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=QzqPKv0y Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6D0B81F0089F; Wed, 11 Nov 2026 00:26:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794356766; bh=PCjIWuc0VWpQkw6vOx/bUK+eJ+5cygz7dQMaILfWO/Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QzqPKv0yEw+YKWKrCfz+vxCbz+MKK+MHGu0/jZAFJWdeQ6XEetEhYPWT3j541LulK OvHt9Cy8EqPJcXh7r523LIh/nQsvkanWMYybKNUi2/Bs3125PqJ3kWZ31hQ4+36LJZ xie6eGZMQNproNMO1LgQ1S14pFto8e9oG8H0iz0UoF9KBVfr/9ANgUe86yCEBA6fLd soqIZy2fuSdeumSPjSY/Boj6wY3xIUSkpVGpJLSeg8m5xabBu+/mwkUrBA0QLVGQfd T3Ll037zMx2r3n8i2bDvahFYmBi/j00oIZEz9sI4HIR4PLfeUwAgeoaROHLObNtjZN bIX8cT73jEiZw== From: Sasha Levin To: stable@vger.kernel.org Cc: Wentao Liang , Juergen Gross , Sasha Levin Subject: [PATCH 6.18.y] xen/gntdev: Fix gntdev_dmabuf ref leak in dmabuf_exp_wait_released() Date: Tue, 10 Nov 2026 19:26:05 -0500 Message-ID: <20261111002104.251573-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261107050950-failed-6.18-6f165abe2b40@kernel.org> References: <20261107050950-failed-6.18-6f165abe2b40@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: Retained kzalloc(sizeof(*obj), GFP_KERNEL) allocation context instead of kzalloc_obj(*obj). ] 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 550980dd3b0bc..5d38506a14f44 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