Bug 2424995 (CVE-2022-50704) - CVE-2022-50704 kernel: USB: gadget: Fix use-after-free during usb config switch
Summary: CVE-2022-50704 kernel: USB: gadget: Fix use-after-free during usb config switch
Keywords:
Status: NEW
Alias: CVE-2022-50704
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-12-24 12:06 UTC by OSIDB Bzimport
Modified: 2025-12-25 10:13 UTC (History)
0 users

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2025-12-24 12:06:51 UTC
In the Linux kernel, the following vulnerability has been resolved:

USB: gadget: Fix use-after-free during usb config switch

In the process of switching USB config from rndis to other config,
if the hardware does not support the ->pullup callback, or the
hardware encounters a low probability fault, both of them may cause
the ->pullup callback to fail, which will then cause a system panic
(use after free).

The gadget drivers sometimes need to be unloaded regardless of the
hardware's behavior.

Analysis as follows:
=======================================================================
(1) write /config/usb_gadget/g1/UDC "none"

gether_disconnect+0x2c/0x1f8
rndis_disable+0x4c/0x74
composite_disconnect+0x74/0xb0
configfs_composite_disconnect+0x60/0x7c
usb_gadget_disconnect+0x70/0x124
usb_gadget_unregister_driver+0xc8/0x1d8
gadget_dev_desc_UDC_store+0xec/0x1e4

(2) rm /config/usb_gadget/g1/configs/b.1/f1

rndis_deregister+0x28/0x54
rndis_free+0x44/0x7c
usb_put_function+0x14/0x1c
config_usb_cfg_unlink+0xc4/0xe0
configfs_unlink+0x124/0x1c8
vfs_unlink+0x114/0x1dc

(3) rmdir /config/usb_gadget/g1/functions/rndis.gs4

panic+0x1fc/0x3d0
do_page_fault+0xa8/0x46c
do_mem_abort+0x3c/0xac
el1_sync_handler+0x40/0x78
0xffffff801138f880
rndis_close+0x28/0x34
eth_stop+0x74/0x110
dev_close_many+0x48/0x194
rollback_registered_many+0x118/0x814
unregister_netdev+0x20/0x30
gether_cleanup+0x1c/0x38
rndis_attr_release+0xc/0x14
kref_put+0x74/0xb8
configfs_rmdir+0x314/0x374

If gadget->ops->pullup() return an error, function rndis_close() will be
called, then it will causes a use-after-free problem.
=======================================================================


Note You need to log in before you can comment on or make changes to this bug.