CVE-2026-98257: rds: ib: use rds_conn_drop() on protocol version mismatch
In the Linux kernel, the following vulnerability has been resolved:
rds: ib: use rdsconndrop() on protocol version mismatch
rdsibcmconnectcomplete() runs from the RDMA-CM event handler with conn->ccmlock held. When the peer negotiates a protocol version older than RDSPROTOCOLCOMPATVERSION, the handler calls rdsconndestroy(), which is only safe in the rmmod path: it synchronously tears the connection down and flushwork()es the shutdown work cpdownw.
That shutdown work (rdsconnshutdown()) needs cpcmlock, which is the very lock the event handler still holds, so the flush never completes: the two workers wait on each other and the RDS connection workqueues stall for good.
All other RDMA-CM failure paths (REJECTED, CONNECTERROR, DISCONNECTED) use rdsconndrop(), which marks the connection RDSCONNERROR and schedules the shutdown work asynchronously. Use it here as well.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
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Fixed in 6.6.158.1-1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.190-1Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1 - Upgrade
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debian/linux-6.12to a version that resolves this vulnerability.Fixed in 6.12.113-1~deb12u1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 5.15.0-202.212 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1 - Compensating control
In rds_ib_cm_connect_complete(), handle peers negotiating a protocol version older than RDS_PROTOCOL_COMPAT_VERSION by calling rds_conn_drop() instead of rds_conn_destroy(), preventing synchronous shutdown and workqueue deadlock.
Event History
Frequently Asked Questions
What conditions are required to trigger the stall?
The system must be using RDS over InfiniBand/RDMA-CM, and a peer must negotiate a protocol version older than RDS_PROTOCOL_COMPAT_VERSION. The problematic path runs during RDMA-CM connection completion while the connection CM lock is held.
What is the operational impact if the condition is triggered?
The connection teardown and shutdown work wait on each other because the shutdown worker needs the lock held by the event handler. This causes the RDS connection workqueues to stall indefinitely.
Is this an accepted CVE requiring vulnerability tracking?
No. The record is marked rejected on 2026-10-06, despite describing a resolved Linux kernel change.