CVE-2026-31754

Summary

In the Linux kernel, the following vulnerability has been resolved:

usb: cdns3: gadget: fix state inconsistency on gadget init failure

When cdns3_gadget_start() fails, the DRD hardware is left in gadget mode while software state remains INACTIVE, creating hardware/software state inconsistency.

When switching to host mode via sysfs: echo host > /sys/class/usb_role/13180000.usb-role-switch/role

The role state is not set to CDNS_ROLE_STATE_ACTIVE due to the error, so cdns_role_stop() skips cleanup because state is still INACTIVE. This violates the DRD controller design specification (Figure22), which requires returning to idle state before switching roles.

This leads to a synchronous external abort in xhci_gen_setup() when setting up the host controller:

[ 516.440698] configfs-gadget 13180000.usb: failed to start g1: -19 [ 516.442035] cdns-usb3 13180000.usb: Failed to add gadget [ 516.443278] cdns-usb3 13180000.usb: set role 2 has failed … [ 1301.375722] xhci-hcd xhci-hcd.1.auto: xHCI Host Controller [ 1301.377716] Internal error: synchronous external abort: 96000010 [#1] PREEMPT SMP [ 1301.382485] pc : xhci_gen_setup+0xa4/0x408 [ 1301.393391] backtrace: … xhci_gen_setup+0xa4/0x408 <– CRASH xhci_plat_setup+0x44/0x58 usb_add_hcd+0x284/0x678 … cdns_role_set+0x9c/0xbc <– Role switch

Fix by calling cdns_drd_gadget_off() in the error path to properly clean up the DRD gadget state.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/fb7110a052467098967284ef14d306810b354937
• https://git.kernel.org/stable/c/9b1d301fbae837bf6979a19030b81d869bb15f7a
• https://git.kernel.org/stable/c/cfca84f5986afceb63a3adf39d4a98e915aebbc2
• https://git.kernel.org/stable/c/c7e475ae3a5593c5db21b3b7dca4ba8bdac9b47f
• https://git.kernel.org/stable/c/5a85599ca4d2584d89dc69f4fc49303b75a42338
• https://git.kernel.org/stable/c/b490f0e477d26d29ed51e5dc47e3b9bd31bcb49f
• https://git.kernel.org/stable/c/c32f8748d70c8fc77676ad92ed76cede17bf2c48

• ←Previous
• Next→