Entreprise française de cybersécurité depuis 2004
☎ 03 60 47 09 81 - info@securiteinfo.com
☎ 03 60 47 09 81 - info@securiteinfo.com
In the Linux kernel, the following vulnerability has been resolved:net/smc: fix LGR and link use-after-free issueWe encountered a LGR/link use-after-free issue, which manifested asthe LGR/link refcnt reaching 0 early and entering the clear process,making resource access unsafe. refcount_t: addition on 0; use-after-free. WARNING: CPU: 14 PID: 107447 at lib/refcount.c:25 refcount_warn_saturate+0x9c/0x140 Workqueue: events smc_lgr_terminate_work [smc] Call trace: refcount_warn_saturate+0x9c/0x140 __smc_lgr_terminate.part.45+0x2a8/0x370 [smc] smc_lgr_terminate_work+0x28/0x30 [smc] process_one_work+0x1b8/0x420 worker_thread+0x158/0x510 kthread+0x114/0x118or refcount_t: underflow; use-after-free. WARNING: CPU: 6 PID: 93140 at lib/refcount.c:28 refcount_warn_saturate+0xf0/0x140 Workqueue: smc_hs_wq smc_listen_work [smc] Call trace: refcount_warn_saturate+0xf0/0x140 smcr_link_put+0x1cc/0x1d8 [smc] smc_conn_free+0x110/0x1b0 [smc] smc_conn_abort+0x50/0x60 [smc] smc_listen_find_device+0x75c/0x790 [smc] smc_listen_work+0x368/0x8a0 [smc] process_one_work+0x1b8/0x420 worker_thread+0x158/0x510 kthread+0x114/0x118It is caused by repeated release of LGR/link refcnt. One suspect is thatsmc_conn_free() is called repeatedly because some smc_conn_free() fromserver listening path are not protected by sock lock.e.g.Calls under socklock | smc_listen_work-------------------------------------------------------lock_sock(sk) | smc_conn_abortsmc_conn_free | \- smc_conn_free\- smcr_link_put | \- smcr_link_put (duplicated)release_sock(sk)So here add sock lock protection in smc_listen_work() path, making itexclusive with other connection operations.
No PoCs from references.
- https://github.com/ARPSyndicate/cve-scores
- https://github.com/cku-heise/euvd-api-doc
- https://github.com/w4zu/Debian_security