usb: dwc3: gadget: Bail from dwc3_gadget_exit() if dwc->gadget is NULL
There exists a possible scenario in which dwc3_gadget_init() can fail:
during during host -> peripheral mode switch in dwc3_set_mode(), and
a pending gadget driver fails to bind. Then, if the DRD undergoes
another mode switch from peripheral->host the resulting
dwc3_gadget_exit() will attempt to reference an invalid and dangling
dwc->gadget pointer as well as call dma_free_coherent() on unmapped
DMA pointers.
The exact scenario can be reproduced as follows:
- Start DWC3 in peripheral mode
- Configure ConfigFS gadget with FunctionFS instance (or use g_ffs)
- Run FunctionFS userspace application (open EPs, write descriptors, etc)
- Bind gadget driver to DWC3's UDC
- Switch DWC3 to host mode
=> dwc3_gadget_exit() is called. usb_del_gadget() will put the
ConfigFS driver instance on the gadget_driver_pending_list
- Stop FunctionFS application (closes the ep files)
- Switch DWC3 to peripheral mode
=> dwc3_gadget_init() fails as usb_add_gadget() calls
check_pending_gadget_drivers() and attempts to rebind the UDC
to the ConfigFS gadget but fails with -19 (-ENODEV) because the
FFS instance is not in FFS_ACTIVE state (userspace has not
re-opened and written the descriptors yet, i.e. desc_ready!=0).
- Switch DWC3 back to host mode
=> dwc3_gadget_exit() is called again, but this time dwc->gadget
is invalid.
Although it can be argued that userspace should take responsibility
for ensuring that the FunctionFS application be ready prior to
allowing the composite driver bind to the UDC, failure to do so
should not result in a panic from the kernel driver.
Fix this by setting dwc->gadget to NULL in the failure path of
dwc3_gadget_init() and add a check to dwc3_gadget_exit() to bail out
unless the gadget pointer is valid.
Metrics
Affected Vendors & Products
No advisories yet.
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Wed, 30 Apr 2025 15:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | NVD-CWE-noinfo | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:5.13:rc5:*:*:*:*:*:* |
|
| Vendors & Products |
Linux
Linux linux Kernel |
|
| Metrics |
cvssV3_1
|
cvssV3_1
|
Wed, 11 Sep 2024 18:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Wed, 11 Sep 2024 13:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-04T07:07:39.188Z
Reserved: 2024-05-21T13:27:52.127Z
Link: CVE-2021-47272
Updated: 2024-08-04T05:32:08.022Z
Status : Analyzed
Published: 2024-05-21T15:15:15.687
Modified: 2025-04-30T14:55:59.530
Link: CVE-2021-47272
OpenCVE Enrichment
No data.