{"id":"CVE-2026-31728","summary":"usb: gadget: u_ether: Fix race between gether_disconnect and eth_stop","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: u_ether: Fix race between gether_disconnect and eth_stop\n\nA race condition between gether_disconnect() and eth_stop() leads to a\nNULL pointer dereference. Specifically, if eth_stop() is triggered\nconcurrently while gether_disconnect() is tearing down the endpoints,\neth_stop() attempts to access the cleared endpoint descriptor, causing\nthe following NPE:\n\n  Unable to handle kernel NULL pointer dereference\n  Call trace:\n   __dwc3_gadget_ep_enable+0x60/0x788\n   dwc3_gadget_ep_enable+0x70/0xe4\n   usb_ep_enable+0x60/0x15c\n   eth_stop+0xb8/0x108\n\nBecause eth_stop() crashes while holding the dev-\u003elock, the thread\nrunning gether_disconnect() fails to acquire the same lock and spins\nforever, resulting in a hardlockup:\n\n  Core - Debugging Information for Hardlockup core(7)\n  Call trace:\n   queued_spin_lock_slowpath+0x94/0x488\n   _raw_spin_lock+0x64/0x6c\n   gether_disconnect+0x19c/0x1e8\n   ncm_set_alt+0x68/0x1a0\n   composite_setup+0x6a0/0xc50\n\nThe root cause is that the clearing of dev-\u003eport_usb in\ngether_disconnect() is delayed until the end of the function.\n\nMove the clearing of dev-\u003eport_usb to the very beginning of\ngether_disconnect() while holding dev-\u003elock. This cuts off the link\nimmediately, ensuring eth_stop() will see dev-\u003eport_usb as NULL and\nsafely bail out.","modified":"2026-07-08T08:00:04.961194369Z","published":"2026-05-01T14:14:28.231Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31728.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/6ad77458637b78ec655e3da5f112c862e6690a9d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8ff689edfeceb5e3ec1623e09af2b2aa0f1098a8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a259ba0bce3b192c04334499690372a250f7d0b1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bbb09bb89ffa571475f66daca9482b974cd29d6a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e1e7a66584bf0aff3becb73c19fa31527889fc9e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e1eabb072c75681f78312c484ccfffb7430f206e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f02980594deef751e42133714aee25228f1494c6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f6813c2b2ae78def76b69e0f9d72f80e4a1c4aca"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31728.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31728"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"2b3d942c4878084a37991a65e66512c02b8fa2ad"},{"fixed":"f02980594deef751e42133714aee25228f1494c6"},{"fixed":"e1e7a66584bf0aff3becb73c19fa31527889fc9e"},{"fixed":"a259ba0bce3b192c04334499690372a250f7d0b1"},{"fixed":"f6813c2b2ae78def76b69e0f9d72f80e4a1c4aca"},{"fixed":"bbb09bb89ffa571475f66daca9482b974cd29d6a"},{"fixed":"6ad77458637b78ec655e3da5f112c862e6690a9d"},{"fixed":"8ff689edfeceb5e3ec1623e09af2b2aa0f1098a8"},{"fixed":"e1eabb072c75681f78312c484ccfffb7430f206e"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31728.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.27"},{"fixed":"5.10.253"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.203"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.169"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.134"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.81"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.22"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.12"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31728.json"}}],"schema_version":"1.7.5"}