{"id":"CVE-2025-40002","summary":"thunderbolt: Fix use-after-free in tb_dp_dprx_work","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nthunderbolt: Fix use-after-free in tb_dp_dprx_work\n\nThe original code relies on cancel_delayed_work() in tb_dp_dprx_stop(),\nwhich does not ensure that the delayed work item tunnel-\u003edprx_work has\nfully completed if it was already running. This leads to use-after-free\nscenarios where tb_tunnel is deallocated by tb_tunnel_put(), while\ntunnel-\u003edprx_work remains active and attempts to dereference tb_tunnel\nin tb_dp_dprx_work().\n\nA typical race condition is illustrated below:\n\nCPU 0                            | CPU 1\ntb_dp_tunnel_active()            |\n  tb_deactivate_and_free_tunnel()| tb_dp_dprx_start()\n    tb_tunnel_deactivate()       |   queue_delayed_work()\n      tb_dp_activate()           |\n        tb_dp_dprx_stop()        | tb_dp_dprx_work() //delayed worker\n          cancel_delayed_work()  |\n    tb_tunnel_put(tunnel);       |\n                                 |   tunnel = container_of(...); //UAF\n                                 |   tunnel-\u003e //UAF\n\nReplacing cancel_delayed_work() with cancel_delayed_work_sync() is\nnot feasible as it would introduce a deadlock: both tb_dp_dprx_work()\nand the cleanup path acquire tb-\u003elock, and cancel_delayed_work_sync()\nwould wait indefinitely for the work item that cannot proceed.\n\nInstead, implement proper reference counting:\n- If cancel_delayed_work() returns true (work is pending), we release\n  the reference in the stop function.\n- If it returns false (work is executing or already completed), the\n  reference is released in delayed work function itself.\n\nThis ensures the tb_tunnel remains valid during work item execution\nwhile preventing memory leaks.\n\nThis bug was found by static analysis.","modified":"2026-03-20T12:43:08.105887Z","published":"2025-10-18T08:03:22.718Z","related":["openSUSE-SU-2025:15671-1","openSUSE-SU-2026:10301-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40002.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/67600ccfc4f38ebd331b9332ac94717bfbc87ea7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c07923f6a8729fc27ee652221a51702ff6654097"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40002.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-40002"},{"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":"d6d458d42e1e1544a18f37f1d5c840e00d5261b9"},{"fixed":"c07923f6a8729fc27ee652221a51702ff6654097"},{"fixed":"67600ccfc4f38ebd331b9332ac94717bfbc87ea7"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-40002.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.14.0"},{"fixed":"6.17.3"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-40002.json"}}],"schema_version":"1.7.5"}