From 6f165abe2b40ede71c98956cd74cd17c18505e75 Mon Sep 17 00:00:00 2001 From: Wentao Liang Date: Wed, 16 Sep 2026 17:09:56 +0000 Subject: [PATCH] xen/gntdev: Fix gntdev_dmabuf ref leak in dmabuf_exp_wait_released() 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> --- 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 83b0df460894..df1883aca850 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_obj(*obj); - 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;