5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Tao Xue xuetao09@huawei.com
commit 151c0aa896c47a4459e07fee7d4843f44c1bb18e upstream.
1. In func configfs_composite_bind() -> composite_os_desc_req_prepare(): if kmalloc fails, the pointer cdev->os_desc_req will be freed but not set to NULL. Then it will return a failure to the upper-level function. 2. in func configfs_composite_bind() -> composite_dev_cleanup(): it will checks whether cdev->os_desc_req is NULL. If it is not NULL, it will attempt to use it.This will lead to a use-after-free issue.
BUG: KASAN: use-after-free in composite_dev_cleanup+0xf4/0x2c0 Read of size 8 at addr 0000004827837a00 by task init/1
CPU: 10 PID: 1 Comm: init Tainted: G O 5.10.97-oh #1 kasan_report+0x188/0x1cc __asan_load8+0xb4/0xbc composite_dev_cleanup+0xf4/0x2c0 configfs_composite_bind+0x210/0x7ac udc_bind_to_driver+0xb4/0x1ec usb_gadget_probe_driver+0xec/0x21c gadget_dev_desc_UDC_store+0x264/0x27c
Fixes: 37a3a533429e ("usb: gadget: OS Feature Descriptors support") Cc: stable stable@kernel.org Signed-off-by: Tao Xue xuetao09@huawei.com Link: https://lore.kernel.org/r/20250721093908.14967-1-xuetao09@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/gadget/composite.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/drivers/usb/gadget/composite.c +++ b/drivers/usb/gadget/composite.c @@ -2241,6 +2241,11 @@ int composite_os_desc_req_prepare(struct if (!cdev->os_desc_req->buf) { ret = -ENOMEM; usb_ep_free_request(ep0, cdev->os_desc_req); + /* + * Set os_desc_req to NULL so that composite_dev_cleanup() + * will not try to free it again. + */ + cdev->os_desc_req = NULL; goto end; } cdev->os_desc_req->context = cdev;