net/rds: clear cp_flags bits individually in rds_conn_path_reset()

Summary

In the Linux kernel, the following vulnerability has been resolved: net/rds: clear cp_flags bits individually in rds_conn_path_reset() rds_conn_path_reset() wipes the whole flag word with a plain cp->cp_flags = 0 store. Every other accessor of that word uses atomic bitops, and some of them can run concurrently with the reset: RDS_LL_SEND_FULL is set from rds_send_xmit() and cleared from the transport completion paths, neither of which holds anything that excludes the shutdown worker. A plain store racing an atomic read-modify-write on the same word is a data race, and whichever side loses has its update silently discarded. Clear the two bits the reset is actually responsible for instead. RDS_IN_XMIT and RDS_RECV_REFILL need no store at all here: they belong to the caller, rds_conn_shutdown(), which waits for both to be clear before calling the transport shutdown and this reset. This also gives every bit in cp_flags a single well-defined writer discipline, which the following patches rely on when they turn RDS_IN_XMIT and RDS_RECV_REFILL into bit locks held across the teardown: a blanket store mid-teardown would destroy lock ownership that an atomic clear preserves. Oracle UEK carries the same conversion ("net/rds: Preserve essential connection state flags"), motivated by its asynchronous shutdown state machine, whose progress and destroy flags must survive the reset. UEK's variant also clears RDS_IN_XMIT and RDS_RECV_REFILL because there the reset runs as the final step of a teardown that owns both bits, making those clears its unlock. Upstream that release belongs in rds_conn_shutdown(): once a later patch in this series turns the two bits into locks held across the teardown, ending ownership needs release semantics and a wake-up that a plain clear inside the reset would not provide. Based on Oracle UEK commit "net/rds: Preserve essential connection state flags" by Gerd Rausch.

Timeline

1. Sep 25, 2026, 10:24 AM UTCCVE published
2. Oct 19, 2026, 9:13 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 00e0f34c616603ba6500f41943cbf89eb4a8a5be · fixed in c9a7c1eb0ad41dcf004a9e870e452cafedcd9172; From 00e0f34c616603ba6500f41943cbf89eb4a8a5be · fixed in b767b48614c38687d717082860de7aa46f3b142c; From 00e0f34c616603ba6500f41943cbf89eb4a8a5be · fixed in b7dc5da660eb5ffa7f7b4d33f2c74cb71c6edd6c; From 00e0f34c616603ba6500f41943cbf89eb4a8a5be · fixed in b8a8b6d25e7426a638c60eaba2129c0664131e84; From 00e0f34c616603ba6500f41943cbf89eb4a8a5be · fixed in ed3ee0ac4aafda50c2f4381eb973beefeb7879ac; From 00e0f34c616603ba6500f41943cbf89eb4a8a5be · fixed in 6b8d7563c28b8112e6e54abe413b028ef3f8c549; From 00e0f34c616603ba6500f41943cbf89eb4a8a5be · fixed in cb62aa8f04655a4df487913949719c0a1266ed73; From 00e0f34c616603ba6500f41943cbf89eb4a8a5be · fixed in 103c4b13c4f50322910078d1c02f29334a574122

• Linux Linux

  2.6.30

• KernelLinux

  From 2.6.30 · fixed in 5.10.271; From 5.11.0 · fixed in 5.15.222; From 5.16.0 · fixed in 6.1.189; From 6.2.0 · fixed in 6.6.158; From 6.7.0 · fixed in 6.12.111; From 6.13.0 · fixed in 6.18.53; From 6.19.0 · fixed in 7.2.7

References 8