{"id":"CVE-2026-98069","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/rds: acquire the fastpath locks in rds_conn_shutdown()\n\nrds_conn_shutdown() quiesces the transmit and receive-refill paths by\nwaiting for RDS_IN_XMIT and RDS_RECV_R…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/rds: acquire the fastpath locks in rds_conn_shutdown()\n\nrds_conn_shutdown() quiesces the transmit and receive-refill paths by\nwaiting for RDS_IN_XMIT and RDS_RECV_R…","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= 0f4b1c7e89e699f588807a914ec6e6396c851a72 < 7febb113795d5de5b690b208f4b0e64a5fad1201","Linux >= 0f4b1c7e89e699f588807a914ec6e6396c851a72 < 900e96c9749a06833801f60c393aa1d405ea226c","Linux >= 0f4b1c7e89e699f588807a914ec6e6396c851a72 < 1fe627e5db5c3f53a9f9f9c8a66671755d306955","Linux >= 0f4b1c7e89e699f588807a914ec6e6396c851a72 < 813f3582ac7ae9f60f917937d54660e0952d5f2d","Linux 2.6.37"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T15:18:05.267","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98069","references":[{"url":"https://git.kernel.org/stable/c/1fe627e5db5c3f53a9f9f9c8a66671755d306955","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7febb113795d5de5b690b208f4b0e64a5fad1201","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/813f3582ac7ae9f60f917937d54660e0952d5f2d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/900e96c9749a06833801f60c393aa1d405ea226c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-25T11:06:38.840Z","slug":"CVE-2026-98069","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/rds: acquire the fastpath locks in rds_conn_shutdown()\n\nrds_conn_shutdown() quiesces the transmit and receive-refill paths by\nwaiting for RDS_IN_XMIT and RDS_RECV_REFILL to be sampled clear, and\nthen runs the transport shutdown and rds_conn_path_reset().  Sampling\nthe bits clear is not the same as owning them: the moment after the\nwait_event() returns, rds_send_xmit() can re-acquire RDS_IN_XMIT (or\nrds_ib_recv_refill() can re-acquire RDS_RECV_REFILL) and run\nconcurrently with the teardown.\n\nThe sender does recheck the connection state after taking the lock,\nbut that recheck is a classic store-buffering pattern: teardown writes\nthe state and reads the bit while the sender writes the bit and reads\nthe state.  acquire_in_xmit() is only an acquire operation, so on\nweakly ordered architectures both sides can miss each other's write,\nand the transmit path then runs while the transport zeroes its rings\n(e.g. rds_ib_ring_init()) and rds_send_path_reset() rewrites the\ntransmit state under it.\n\nOracle UEK fixed the same class of crashes - a 14-year tail of\nBUG_ON()s in rds_ib_sub_signaled(), unexpected op-codes and NULL\ndereferences in rds_ib_send_cqe_handler() during failover testing -\nby making the teardown path *acquire* the fastpath bit locks instead\nof testing them (\"rds: Make sure transmit path and connection\ntear-down does not run concurrently\").  Ownership of a single word is\ndecided by RMW atomicity, so no cross-variable ordering is needed.\n\nDo the same here: take both locks before calling the transport\nshutdown, hold them across rds_conn_path_reset(), and release them\nexplicitly with a wake-up afterwards.  Both are released with\nclear_bit_unlock(), so that the ring re-initialization done by the\ntransport shutdown and the transmit state rewritten by\nrds_send_path_reset() are ordered before either bit is seen clear by\nthe next acquire_in_xmit() or acquire_refill().\n\nThe fastpath users of these bits - rds_send_xmit() and\nrds_ib_recv_refill() - are trylock style and back off while teardown\nowns the locks, so no new lock dependency is introduced for them.\nrds_tcp_reset_callbacks() is different: since the previous patch it\nacquires RDS_IN_XMIT as well, and it blocks doing so, so its wait now\nspans the teardown instead of at most one send batch.  That waiter\nruns from rds_tcp_accept_one() on the single-threaded krdsd workqueue\nand holds rds_tcp_accept_lock and t_conn_path_lock while it waits, so\na duelling SYN accepted while its path is being torn down parks\naccept processing for the duration of the teardown - for TCP bounded\nby the (up to 5 s) drain loop in rds_tcp_conn_path_shutdown().  An IB\npath's drain in rds_ib_conn_path_shutdown() has no round cap, but no\nblocking waiter either: rds_tcp_reset_callbacks() is the only blocking\nacquirer of these bits and waits only on its own TCP path, and the\nfastpaths are trylock-and-back-off on both transports, so a long IB\ndrain lengthens only that path's own quiesce.  The\nwindow is narrow: the accept-side state check has to pass before the\nteardown moves the path to RDS_CONN_DISCONNECTING.\n\nBecause krdsd is a single global workqueue, everything else queued\nthere - accept processing for other connections and network\nnamespaces, and the flush_workqueue(rds_wq) in rds_tcp_listen_stop()\nduring namespace teardown - waits behind the parked accept worker for\nthat time.  It cannot deadlock, although the waits do point at each\nother: the teardown blocks until the bit's holder releases it, and\nthe holder may be that krdsd accept worker.  The holder finishes\nwithout needing anything the teardown owns: the sync cancels\nrds_tcp_reset_callbacks() issues target cp_send_w and cp_recv_w on\nthe path's ordered cp_wq, whose only execution slot is occupied by\nthe blocked cp_down_w itself, so they are pending at most and cancel\nwithout flushing - a reliance on cp_wq being ordered that is now\nnoted next to those cancels (on \n---truncated---\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":210920,"id":"CVE-2026-98069","ts":1790349115750,"field":"cvss","old":null,"new":"8.1"},{"seq":210919,"id":"CVE-2026-98069","ts":1790349115750,"field":"severity","old":"none","new":"high"}]}