CVE-2022-50704 USB: gadget: Fix use-after-free during usb config switch
A use-after-free in the Linux kernel USB gadget driver allows local attackers with high privileges to cause a system panic during USB configuration switching.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-50704?
CVE-2022-50704 is an use after free vulnerability in Linux, published on 24 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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. =======================================================================
Which versions are affected by CVE-2022-50704?
How do I fix CVE-2022-50704?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2022-50704 being exploited?
There is no known exploitation of CVE-2022-50704 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2022-50704, GHSA-mj7r-48h2-hmpx, ROOT-OS-DEBIAN-11-CVE-2022-50704, ROOT-OS-UBUNTU-2204-CVE-2022-50704, UBUNTU-CVE-2022-50704.