{"schema_version":"1.9.0","id":"CVE-2026-63905","published":"2026-07-19T14:55:12.270Z","modified":"2026-08-31T18:26:09.460379043Z","related":["SUSE-SU-2026:23066-1","SUSE-SU-2026:23068-1","SUSE-SU-2026:23193-1","SUSE-SU-2026:23194-1","SUSE-SU-2026:23221-1","SUSE-SU-2026:23231-1","SUSE-SU-2026:23237-1","SUSE-SU-2026:23241-1","SUSE-SU-2026:23244-1","SUSE-SU-2026:3790-1","SUSE-SU-2026:3810-1","openSUSE-SU-2026:21555-1"],"summary":"usbip: vudc: Fix use after free bug in vudc_remove due to race condition","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nusbip: vudc: Fix use after free bug in vudc_remove due to race condition\n\nThis patch follows up Zheng Wang's 2023 report of a use-after-free in\nvudc_remove(). The original thread stalled on Shuah Khan's request for\nruntime testing of the unplug/unbind path. This patch supplies that\ntesting and keeps Zheng's original fix shape.\n\nIn vudc_probe(), v_init_timer() binds udc->tr_timer.timer to v_timer().\nusbip_sockfd_store() starts the timer via v_start_timer()/v_kick_timer().\nvudc_remove() can then free the containing struct vudc while the timer is\nstill pending or executing.\n\nKASAN confirms the race on an unpatched x86_64 QEMU guest with\nCONFIG_KASAN=y, CONFIG_USBIP_VUDC=y, CONFIG_USB_ZERO=y, and a tight loop\nthat repeatedly writes a socket fd to usbip_sockfd, closes the socket\npair, and unbinds/rebinds usbip-vudc.0:\n\n  BUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x8ba/0x8e0\n  Write of size 8 at addr ffff888001b80740 by task trigger_and_unb/239\n  Allocated by task 239:\n    vudc_probe+0x4d/0xaa0\n  Freed by task 239:\n    kfree+0x18f/0x520\n    device_release_driver_internal+0x388/0x540\n    unbind_store+0xd9/0x100\n\nThis lands in the timer core rather than v_timer() itself because the\nembedded timer_list is being walked after its containing struct vudc has\nalready been freed. The underlying lifetime bug is the same one Zheng\nreported.\n\nWith v_stop_timer() called from vudc_remove() and the timer deleted\nsynchronously, the same harness completed 5000 bind/unbind iterations\nwith no KASAN report.","affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b6a0ca11186759ad7045d68a5447b1e89f658384"},{"fixed":"61704e5cf9cd7464b510eb606e7e2978b1160a64"},{"fixed":"dcc1c90b28b28b7c493547506297e78653f81952"},{"fixed":"1036ac6148995feaf486014d32bf26bf993c06a9"},{"fixed":"a0638db2340ee053ab0450656a763fd111475e54"},{"fixed":"d07ed707467ce05ea9c03412d0c5ee9d0fe386a6"},{"fixed":"88d459e5b5a46da1ef9fd6f52d9439343edeec88"},{"fixed":"207bf80362df3fce8ebc9723351dcb1bc6d9ed0f"},{"fixed":"d96209626a29ea64666be98c30b30ac82e5f1be6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63905.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.7.0"},{"fixed":"5.10.259"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.210"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.176"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.143"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.93"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.35"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.12"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63905.json"}}],"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1036ac6148995feaf486014d32bf26bf993c06a9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/207bf80362df3fce8ebc9723351dcb1bc6d9ed0f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/61704e5cf9cd7464b510eb606e7e2978b1160a64"},{"type":"WEB","url":"https://git.kernel.org/stable/c/88d459e5b5a46da1ef9fd6f52d9439343edeec88"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a0638db2340ee053ab0450656a763fd111475e54"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d07ed707467ce05ea9c03412d0c5ee9d0fe386a6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d96209626a29ea64666be98c30b30ac82e5f1be6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dcc1c90b28b28b7c493547506297e78653f81952"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63905.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63905"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63905.json"}}