CVE-2026-63905

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> usbip: vudc: Fix use after free bug in vudc_remove due to race condition<br /> <br /> This patch follows up Zheng Wang&amp;#39;s 2023 report of a use-after-free in<br /> vudc_remove(). The original thread stalled on Shuah Khan&amp;#39;s request for<br /> runtime testing of the unplug/unbind path. This patch supplies that<br /> testing and keeps Zheng&amp;#39;s original fix shape.<br /> <br /> In vudc_probe(), v_init_timer() binds udc-&gt;tr_timer.timer to v_timer().<br /> usbip_sockfd_store() starts the timer via v_start_timer()/v_kick_timer().<br /> vudc_remove() can then free the containing struct vudc while the timer is<br /> still pending or executing.<br /> <br /> KASAN confirms the race on an unpatched x86_64 QEMU guest with<br /> CONFIG_KASAN=y, CONFIG_USBIP_VUDC=y, CONFIG_USB_ZERO=y, and a tight loop<br /> that repeatedly writes a socket fd to usbip_sockfd, closes the socket<br /> pair, and unbinds/rebinds usbip-vudc.0:<br /> <br /> BUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x8ba/0x8e0<br /> Write of size 8 at addr ffff888001b80740 by task trigger_and_unb/239<br /> Allocated by task 239:<br /> vudc_probe+0x4d/0xaa0<br /> Freed by task 239:<br /> kfree+0x18f/0x520<br /> device_release_driver_internal+0x388/0x540<br /> unbind_store+0xd9/0x100<br /> <br /> This lands in the timer core rather than v_timer() itself because the<br /> embedded timer_list is being walked after its containing struct vudc has<br /> already been freed. The underlying lifetime bug is the same one Zheng<br /> reported.<br /> <br /> With v_stop_timer() called from vudc_remove() and the timer deleted<br /> synchronously, the same harness completed 5000 bind/unbind iterations<br /> with no KASAN report.