FAILED: patch "[PATCH] usb: gadget: f_ncm: Refactor bind path to use __free()" failed to apply to 6.6-stable tree
Subsystems (2)
[email protected]
maintainerThe patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 75a5b8d4ddd4eb6b16cb0b475d14ff4ae64295ef
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025101602-clumsily-lived-dd4b@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 75a5b8d4ddd4eb6b16cb0b475d14ff4ae64295ef Mon Sep 17 00:00:00 2001
From: Kuen-Han Tsai <[email protected]>
Date: Tue, 16 Sep 2025 16:21:34 +0800
Subject: [PATCH] usb: gadget: f_ncm: Refactor bind path to use __free()
After an bind/unbind cycle, the ncm->notify_req is left stale. If a subsequent bind fails, the unified error label attempts to free this stale request, leading to a NULL pointer dereference when accessing ep->ops->free_request.
Refactor the error handling in the bind path to use the __free() automatic cleanup mechanism.
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 Call trace: usb_ep_free_request+0x2c/0xec ncm_bind+0x39c/0x3dc usb_add_function+0xcc/0x1f0 configfs_composite_bind+0x468/0x588 gadget_bind_driver+0x104/0x270 really_probe+0x190/0x374 __driver_probe_device+0xa0/0x12c driver_probe_device+0x3c/0x218 __device_attach_driver+0x14c/0x188 bus_for_each_drv+0x10c/0x168 __device_attach+0xfc/0x198 device_initial_probe+0x14/0x24 bus_probe_device+0x94/0x11c device_add+0x268/0x48c usb_add_gadget+0x198/0x28c dwc3_gadget_init+0x700/0x858 __dwc3_set_mode+0x3cc/0x664 process_scheduled_works+0x1d8/0x488 worker_thread+0x244/0x334 kthread+0x114/0x1bc ret_from_fork+0x10/0x20
drivers/usb/gadget/function/f_ncm.c +33 -45
@@ -11,6 +11,7 @@* Copyright (C) 2008 Nokia Corporation */ +#include <linux/cleanup.h> #include <linux/kernel.h> #include <linux/interrupt.h> #include <linux/module.h>
@@ -20,6 +21,7 @@#include <linux/string_choices.h> #include <linux/usb/cdc.h> +#include <linux/usb/gadget.h> #include "u_ether.h" #include "u_ether_configfs.h"
@@ -1436,18 +1438,18 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)struct usb_ep *ep;struct f_ncm_opts *ncm_opts; + struct usb_os_desc_table *os_desc_table __free(kfree) = NULL; + struct usb_request *request __free(free_usb_request) = NULL; +if (!can_support_ecm (cdev->gadget))return -EINVAL ; ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst);if (cdev->use_os_string) { - f->os_desc_table =kzalloc (sizeof (*f->os_desc_table), -GFP_KERNEL ); -if (!f->os_desc_table) + os_desc_table =kzalloc (sizeof (*os_desc_table),GFP_KERNEL ); +if (!os_desc_table)return -ENOMEM ; - f->os_desc_n =1 ; - f->os_desc_table[0 ].os_desc = &ncm_opts->ncm_os_desc; }mutex_lock (&ncm_opts->lock);
@@ -1459,16 +1461,15 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)mutex_unlock (&ncm_opts->lock);if (status) - goto fail; +return status; ncm_opts->bound = true; us =usb_gstrings_attach (cdev, ncm_strings,ARRAY_SIZE (ncm_string_defs)); -if (IS_ERR (us)) { - status =PTR_ERR (us); - goto fail; - } +if (IS_ERR (us)) +return PTR_ERR (us); + ncm_control_intf.iInterface = us[STRING_CTRL_IDX ].id; ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX ].id; ncm_data_intf.iInterface = us[STRING_DATA_IDX ].id;
@@ -1478,20 +1479,16 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)/* allocate instance-specific interface IDs */ status =usb_interface_id (c, f);if (status <0 ) - goto fail; +return status; ncm->ctrl_id = status; ncm_iad_desc.bFirstInterface = status; ncm_control_intf.bInterfaceNumber = status; ncm_union_desc.bMasterInterface0 = status; -if (cdev->use_os_string) - f->os_desc_table[0 ].if_id = - ncm_iad_desc.bFirstInterface; - status =usb_interface_id (c, f);if (status <0 ) - goto fail; +return status; ncm->data_id = status; ncm_data_nop_intf.bInterfaceNumber = status;
@@ -1500,35 +1497,31 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f) ecm_desc.wMaxSegmentSize =cpu_to_le16 (ncm_opts->max_segment_size); - status = -ENODEV ; -/* allocate instance-specific endpoints */ ep =usb_ep_autoconfig (cdev->gadget, &fs_ncm_in_desc);if (!ep) - goto fail; +return -ENODEV ; ncm->port.in_ep = ep; ep =usb_ep_autoconfig (cdev->gadget, &fs_ncm_out_desc);if (!ep) - goto fail; +return -ENODEV ; ncm->port.out_ep = ep; ep =usb_ep_autoconfig (cdev->gadget, &fs_ncm_notify_desc);if (!ep) - goto fail; +return -ENODEV ; ncm->notify = ep; - status = -ENOMEM ; -/* allocate notification request and buffer */ - ncm->notify_req =usb_ep_alloc_request (ep,GFP_KERNEL ); -if (!ncm->notify_req) - goto fail; - ncm->notify_req->buf =kmalloc (NCM_STATUS_BYTECOUNT ,GFP_KERNEL ); -if (!ncm->notify_req->buf) - goto fail; - ncm->notify_req->context = ncm; - ncm->notify_req->complete = ncm_notify_complete; + request =usb_ep_alloc_request (ep,GFP_KERNEL ); +if (!request) +return -ENOMEM ; + request->buf =kmalloc (NCM_STATUS_BYTECOUNT ,GFP_KERNEL ); +if (!request->buf) +return -ENOMEM ; + request->context = ncm; + request->complete = ncm_notify_complete;/* * support all relevant hardware speeds... we expect that when
@@ -1548,7 +1541,7 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f) status =usb_assign_descriptors (f, ncm_fs_function, ncm_hs_function, ncm_ss_function, ncm_ss_function);if (status) - goto fail; +return status;/* * NOTE: all that is done without knowing or caring about
@@ -1561,23 +1554,18 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)hrtimer_setup (&ncm->task_timer, ncm_tx_timeout,CLOCK_MONOTONIC ,HRTIMER_MODE_REL_SOFT ); +if (cdev->use_os_string) { + os_desc_table[0 ].os_desc = &ncm_opts->ncm_os_desc; + os_desc_table[0 ].if_id = ncm_iad_desc.bFirstInterface; + f->os_desc_table =no_free_ptr (os_desc_table); + f->os_desc_n =1 ; + } + ncm->notify_req =no_free_ptr (request); +DBG (cdev,"CDC Network: IN/%s OUT/%s NOTIFY/%s\n" , ncm->port.in_ep->name, ncm->port.out_ep->name, ncm->notify->name);return 0 ; - -fail: -kfree (f->os_desc_table); - f->os_desc_n =0 ; - -if (ncm->notify_req) { -kfree (ncm->notify_req->buf); -usb_ep_free_request (ncm->notify, ncm->notify_req); - } - -ERROR (cdev,"%s: can't bind, err %d\n" , f->name, status); - -return status; }static inline struct f_ncm_opts *to_f_ncm_opts (struct config_item *item)
Sasha Levin
maintainerPATCH 1/3 usb: gadget: Store endpoint pointer in usb_request
From: Kuen-Han Tsai <[email protected]>
[ Upstream commit bfb1d99d969fe3b892db30848aeebfa19d21f57f ]
Gadget function drivers often have goto-based error handling in their bind paths, which can be bug-prone. Refactoring these paths to use __free() scope-based cleanup is desirable, but currently blocked.
The blocker is that usb_ep_free_request(ep, req) requires two parameters, while the __free() mechanism can only pass a pointer to the request itself.
Store an endpoint pointer in the struct usb_request. The pointer is populated centrally in usb_ep_alloc_request() on every successful allocation, making the request object self-contained.
Stable-dep-of: 75a5b8d4ddd4 ("usb: gadget: f_ncm: Refactor bind path to use __free()")
--- drivers/usb/gadget/udc/core.c | 3 +++ include/linux/usb/gadget.h | 2 ++ 2 files changed, 5 insertions(+)
drivers/usb/gadget/udc/core.c +3 -0
@@ -194,6 +194,9 @@ struct usb_request *usb_ep_alloc_request(struct usb_ep *ep, req = ep->ops->alloc_request (ep, gfp_flags); +if (req) + req->ep = ep; +trace_usb_ep_alloc_request (ep, req, req ?0 : -ENOMEM );return req;
include/linux/usb/gadget.h +2 -0
@@ -32,6 +32,7 @@ struct usb_ep;/** * struct usb_request - describes one i/o request +* @ep: The associated endpoint set by usb_ep_alloc_request(). * @buf: Buffer used for data. Always provide this; some controllers * only use PIO, or don't use DMA for some endpoints. * @dma: DMA address corresponding to 'buf'. If you don't set this
@@ -97,6 +98,7 @@ struct usb_ep;*/ struct usb_request { +struct usb_ep *ep;void *buf;unsigned length;dma_addr_t dma;
Signature · 1 line
2.51.0
Sasha Levin
maintainerPATCH 2/3 usb: gadget: Introduce free_usb_request helper
From: Kuen-Han Tsai <[email protected]>
[ Upstream commit 201c53c687f2b55a7cc6d9f4000af4797860174b ]
Introduce the free_usb_request() function that frees both the request's buffer and the request itself.
This function serves as the cleanup callback for DEFINE_FREE() to enable automatic, scope-based cleanup for usb_request pointers.
Stable-dep-of: 75a5b8d4ddd4 ("usb: gadget: f_ncm: Refactor bind path to use __free()")
--- include/linux/usb/gadget.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)
include/linux/usb/gadget.h +23 -0
@@ -15,6 +15,7 @@#ifndef __LINUX_USB_GADGET_H#define __LINUX_USB_GADGET_H +#include <linux/cleanup.h> #include <linux/configfs.h> #include <linux/device.h> #include <linux/errno.h>
@@ -291,6 +292,28 @@ static inline void usb_ep_fifo_flush(struct usb_ep *ep)/*-------------------------------------------------------------------------*/ +/** +* free_usb_request - frees a usb_request object and its buffer +* @req: the request being freed +* +* This helper function frees both the request's buffer and the request object +* itself by calling usb_ep_free_request(). Its signature is designed to be used +* with DEFINE_FREE() to enable automatic, scope-based cleanup for usb_request +* pointers. +*/ +static inline void free_usb_request (struct usb_request *req) +{ +if (!req) +return ; + +kfree (req->buf); +usb_ep_free_request (req->ep, req); +} + +DEFINE_FREE(free_usb_request, struct usb_request *, free_usb_request(_T)) + +/*-------------------------------------------------------------------------*/ +struct usb_dcd_config_params {__u8 bU1devExitLat;/* U1 Device exit Latency */ #define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01/* Less then 1 microsec */
Signature · 1 line
2.51.0
Sasha Levin
maintainerPATCH 3/3 usb: gadget: f_ncm: Refactor bind path to use __free()
In reply to Sasha LevinFrom: Kuen-Han Tsai <[email protected]>
[ Upstream commit 75a5b8d4ddd4eb6b16cb0b475d14ff4ae64295ef ]
After an bind/unbind cycle, the ncm->notify_req is left stale. If a subsequent bind fails, the unified error label attempts to free this stale request, leading to a NULL pointer dereference when accessing ep->ops->free_request.
Refactor the error handling in the bind path to use the __free() automatic cleanup mechanism.
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 Call trace: usb_ep_free_request+0x2c/0xec ncm_bind+0x39c/0x3dc usb_add_function+0xcc/0x1f0 configfs_composite_bind+0x468/0x588 gadget_bind_driver+0x104/0x270 really_probe+0x190/0x374 __driver_probe_device+0xa0/0x12c driver_probe_device+0x3c/0x218 __device_attach_driver+0x14c/0x188 bus_for_each_drv+0x10c/0x168 __device_attach+0xfc/0x198 device_initial_probe+0x14/0x24 bus_probe_device+0x94/0x11c device_add+0x268/0x48c usb_add_gadget+0x198/0x28c dwc3_gadget_init+0x700/0x858 __dwc3_set_mode+0x3cc/0x664 process_scheduled_works+0x1d8/0x488 worker_thread+0x244/0x334 kthread+0x114/0x1bc ret_from_fork+0x10/0x20
--- drivers/usb/gadget/function/f_ncm.c | 78 ++++++++++++----------------- 1 file changed, 33 insertions(+), 45 deletions(-)
drivers/usb/gadget/function/f_ncm.c +33 -45
@@ -11,6 +11,7 @@* Copyright (C) 2008 Nokia Corporation */ +#include <linux/cleanup.h> #include <linux/kernel.h> #include <linux/interrupt.h> #include <linux/module.h>
@@ -19,6 +20,7 @@#include <linux/crc32.h> #include <linux/usb/cdc.h> +#include <linux/usb/gadget.h> #include "u_ether.h" #include "u_ether_configfs.h"
@@ -1422,18 +1424,18 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)struct usb_ep *ep;struct f_ncm_opts *ncm_opts; + struct usb_os_desc_table *os_desc_table __free(kfree) = NULL; + struct usb_request *request __free(free_usb_request) = NULL; +if (!can_support_ecm (cdev->gadget))return -EINVAL ; ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst);if (cdev->use_os_string) { - f->os_desc_table =kzalloc (sizeof (*f->os_desc_table), -GFP_KERNEL ); -if (!f->os_desc_table) + os_desc_table =kzalloc (sizeof (*os_desc_table),GFP_KERNEL ); +if (!os_desc_table)return -ENOMEM ; - f->os_desc_n =1 ; - f->os_desc_table[0 ].os_desc = &ncm_opts->ncm_os_desc; }mutex_lock (&ncm_opts->lock);
@@ -1443,16 +1445,15 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)mutex_unlock (&ncm_opts->lock);if (status) - goto fail; +return status; ncm_opts->bound = true; us =usb_gstrings_attach (cdev, ncm_strings,ARRAY_SIZE (ncm_string_defs)); -if (IS_ERR (us)) { - status =PTR_ERR (us); - goto fail; - } +if (IS_ERR (us)) +return PTR_ERR (us); + ncm_control_intf.iInterface = us[STRING_CTRL_IDX ].id; ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX ].id; ncm_data_intf.iInterface = us[STRING_DATA_IDX ].id;
@@ -1462,55 +1463,47 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)/* allocate instance-specific interface IDs */ status =usb_interface_id (c, f);if (status <0 ) - goto fail; +return status; ncm->ctrl_id = status; ncm_iad_desc.bFirstInterface = status; ncm_control_intf.bInterfaceNumber = status; ncm_union_desc.bMasterInterface0 = status; -if (cdev->use_os_string) - f->os_desc_table[0 ].if_id = - ncm_iad_desc.bFirstInterface; - status =usb_interface_id (c, f);if (status <0 ) - goto fail; +return status; ncm->data_id = status; ncm_data_nop_intf.bInterfaceNumber = status; ncm_data_intf.bInterfaceNumber = status; ncm_union_desc.bSlaveInterface0 = status; - status = -ENODEV ; -/* allocate instance-specific endpoints */ ep =usb_ep_autoconfig (cdev->gadget, &fs_ncm_in_desc);if (!ep) - goto fail; +return -ENODEV ; ncm->port.in_ep = ep; ep =usb_ep_autoconfig (cdev->gadget, &fs_ncm_out_desc);if (!ep) - goto fail; +return -ENODEV ; ncm->port.out_ep = ep; ep =usb_ep_autoconfig (cdev->gadget, &fs_ncm_notify_desc);if (!ep) - goto fail; +return -ENODEV ; ncm->notify = ep; - status = -ENOMEM ; -/* allocate notification request and buffer */ - ncm->notify_req =usb_ep_alloc_request (ep,GFP_KERNEL ); -if (!ncm->notify_req) - goto fail; - ncm->notify_req->buf =kmalloc (NCM_STATUS_BYTECOUNT ,GFP_KERNEL ); -if (!ncm->notify_req->buf) - goto fail; - ncm->notify_req->context = ncm; - ncm->notify_req->complete = ncm_notify_complete; + request =usb_ep_alloc_request (ep,GFP_KERNEL ); +if (!request) +return -ENOMEM ; + request->buf =kmalloc (NCM_STATUS_BYTECOUNT ,GFP_KERNEL ); +if (!request->buf) +return -ENOMEM ; + request->context = ncm; + request->complete = ncm_notify_complete;/* * support all relevant hardware speeds... we expect that when
@@ -1530,7 +1523,7 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f) status =usb_assign_descriptors (f, ncm_fs_function, ncm_hs_function, ncm_ss_function, ncm_ss_function);if (status) - goto fail; +return status;/* * NOTE: all that is done without knowing or caring about
@@ -1544,23 +1537,18 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)hrtimer_init (&ncm->task_timer,CLOCK_MONOTONIC ,HRTIMER_MODE_REL_SOFT ); ncm->task_timer.function = ncm_tx_timeout; +if (cdev->use_os_string) { + os_desc_table[0 ].os_desc = &ncm_opts->ncm_os_desc; + os_desc_table[0 ].if_id = ncm_iad_desc.bFirstInterface; + f->os_desc_table =no_free_ptr (os_desc_table); + f->os_desc_n =1 ; + } + ncm->notify_req =no_free_ptr (request); +DBG (cdev,"CDC Network: IN/%s OUT/%s NOTIFY/%s\n" , ncm->port.in_ep->name, ncm->port.out_ep->name, ncm->notify->name);return 0 ; - -fail: -kfree (f->os_desc_table); - f->os_desc_n =0 ; - -if (ncm->notify_req) { -kfree (ncm->notify_req->buf); -usb_ep_free_request (ncm->notify, ncm->notify_req); - } - -ERROR (cdev,"%s: can't bind, err %d\n" , f->name, status); - -return status; }static inline struct f_ncm_opts *to_f_ncm_opts (struct config_item *item)
Signature · 1 line
2.51.0