Description
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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
00e0f34c616603ba6500f41943cbf89eb4a8a5be to < c9a7c1eb0ad41dcf004a9e870e452cafedcd9172affected00e0f34c616603ba6500f41943cbf89eb4a8a5be to < b767b48614c38687d717082860de7aa46f3b142caffected00e0f34c616603ba6500f41943cbf89eb4a8a5be to < b7dc5da660eb5ffa7f7b4d33f2c74cb71c6edd6caffected00e0f34c616603ba6500f41943cbf89eb4a8a5be to < b8a8b6d25e7426a638c60eaba2129c0664131e84affected00e0f34c616603ba6500f41943cbf89eb4a8a5be to < ed3ee0ac4aafda50c2f4381eb973beefeb7879acaffected00e0f34c616603ba6500f41943cbf89eb4a8a5be to < 6b8d7563c28b8112e6e54abe413b028ef3f8c549affected00e0f34c616603ba6500f41943cbf89eb4a8a5be to < cb62aa8f04655a4df487913949719c0a1266ed73affected00e0f34c616603ba6500f41943cbf89eb4a8a5be to < 103c4b13c4f50322910078d1c02f29334a574122affected
Linux Linux
Default version status: affected
2.6.30affected0 to < 2.6.30unaffected5.10.271 to ≤ 5.10.*unaffected5.15.222 to ≤ 5.15.*unaffected6.1.189 to ≤ 6.1.*unaffected6.6.158 to ≤ 6.6.*unaffected6.12.111 to ≤ 6.12.*unaffected6.18.53 to ≤ 6.18.*unaffected7.2.7 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/c9a7c1eb0ad41dcf004a9e870e452cafedcd9172 ↗
- https://git.kernel.org/stable/c/b767b48614c38687d717082860de7aa46f3b142c ↗
- https://git.kernel.org/stable/c/b7dc5da660eb5ffa7f7b4d33f2c74cb71c6edd6c ↗
- https://git.kernel.org/stable/c/b8a8b6d25e7426a638c60eaba2129c0664131e84 ↗
- https://git.kernel.org/stable/c/ed3ee0ac4aafda50c2f4381eb973beefeb7879ac ↗
- https://git.kernel.org/stable/c/6b8d7563c28b8112e6e54abe413b028ef3f8c549 ↗
- https://git.kernel.org/stable/c/cb62aa8f04655a4df487913949719c0a1266ed73 ↗
- https://git.kernel.org/stable/c/103c4b13c4f50322910078d1c02f29334a574122 ↗