CVE-2026-68344

Summary

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

usb: atm: ueagle-atm: reject descriptors that confuse probe and disconnect

uea_probe() distinguishes a pre-firmware device from a post-firmware one using the USB id (UEA_IS_PREFIRM()), and stores a different object as the interface data in each case: a 'struct completion' for a pre-firmware device (to be waited on in .disconnect()), or a 'struct usbatm_data' for a post-firmware one.

uea_disconnect() instead tells the two apart by the number of interfaces of the active configuration (a pre-firmware device exposes a single interface, ADI930 has 2 and eagle has 3), and casts the interface data accordingly.

Because the two handlers use different criteria, a crafted device that advertises a pre-firmware id together with a multi-interface descriptor (or a post-firmware id with a single interface) makes them disagree: the small 'struct completion' stored by uea_probe() is then passed to usbatm_usb_disconnect(), which casts it to 'struct usbatm_data' and takes instance->serialize, reading past the end of the allocation:

BUG: KASAN: slab-out-of-bounds in __mutex_lock+0x152a/0x1b80 Read of size 8 at addr ffff8880470e2c60 by task kworker/1:2/982 … __mutex_lock+0x152a/0x1b80 usbatm_usb_disconnect+0x70/0x820 uea_disconnect+0x133/0x2c0 usb_unbind_interface+0x1dd/0x9e0 … which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes to the right of allocated 96-byte region [ffff8880470e2c00, ffff8880470e2c60)

Reject such inconsistent descriptors in uea_probe() so that both handlers always make the same pre/post-firmware decision.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/c035b1198906dd5bd3df9a3045b59254bad1ea7a
• https://git.kernel.org/stable/c/9904a46401198872ab3de34fd11f383831ef3428
• https://git.kernel.org/stable/c/d0a57f19fe2865b9747484f5f9c631f944ed9a0f
• https://git.kernel.org/stable/c/0cc0c4c14150bb5a16b88dd61368f96cd4caa9ce
• https://git.kernel.org/stable/c/71132cedd1ecbc4032d76e9928c18a10f7e39b80

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