https://vulnerability.circl.lu Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Thu, 01 Oct 2026 02:56:33 +0000 https://vulnerability.circl.lu/vuln/cve-2026-89546 <p><strong>Affected:</strong> Linux</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>SUNRPC: close backchannel before destroying callback service</p> <p>A backchannel receive can complete a request while the NFS callback service is being torn down. xprt_complete_bc_request() removes the request from bc_pa_list, drops bc_alloc_count, marks the request in use, and then asks xprt_enqueue_bc_request() to hand it to the callback service.</p> <p>If teardown has already cleared xprt-&gt;bc_serv, xprt_enqueue_bc_request() currently returns without enqueueing or freeing the committed request. The xprt_get() taken on entry is leaked as well. If the producer wins the race before bc_serv is cleared, it can also enqueue onto sv_cb_list after nfs_callback_down() has stopped the callback threads, leaving the request linked to a svc_serv that is about to be freed.</p> <p>Close the producer side before callback threads are stopped. Add xprt_svc_shutdown_bc() to clear xprt-&gt;bc_serv under bc_pa_lock, and call it on callback shutdown and callback-start failure before stopping the service threads. Requests that lose the NULL transition in xprt_enqueue_bc_request() are released through the normal backchannel free path after balancing bc_slot_count. Finally, drain any remaining sv_cb_list requests after the callback threads have stopped and before svc_destroy() frees the service.</p> <p><strong>Affected:</strong> Linux</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>SUNRPC: close backchannel before destroying callback service</p> <p>A backchannel receive can complete a request while the NFS callback service is being torn down. xprt_complete_bc_request() removes the request from bc_pa_list, drops bc_alloc_count, marks the request in use, and then asks xprt_enqueue_bc_request() to hand it to the callback service.</p> <p>If teardown has already cleared xprt-&gt;bc_serv, xprt_enqueue_bc_request() currently returns without enqueueing or freeing the committed request. The xprt_get() taken on entry is leaked as well. If the producer wins the race before bc_serv is cleared, it can also enqueue onto sv_cb_list after nfs_callback_down() has stopped the callback threads, leaving the request linked to a svc_serv that is about to be freed.</p> <p>Close the producer side before callback threads are stopped. Add xprt_svc_shutdown_bc() to clear xprt-&gt;bc_serv under bc_pa_lock, and call it on callback shutdown and callback-start failure before stopping the service threads. Requests that lose the NULL transition in xprt_enqueue_bc_request() are released through the normal backchannel free path after balancing bc_slot_count. Finally, drain any remaining sv_cb_list requests after the callback threads have stopped and before svc_destroy() frees the service.</p> https://vulnerability.circl.lu/vuln/cve-2026-89546