Description (CNA)
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 (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 00e0f34c616603ba6500f41943cbf89eb4a8a5be before c9a7c1eb0ad41dcf004a9e870e452cafedcd9172; affected 00e0f34c616603ba6500f41943cbf89eb4a8a5be before b767b48614c38687d717082860de7aa46f3b142c; affected 00e0f34c616603ba6500f41943cbf89eb4a8a5be before b7dc5da660eb5ffa7f7b4d33f2c74cb71c6edd6c; affected 00e0f34c616603ba6500f41943cbf89eb4a8a5be before b8a8b6d25e7426a638c60eaba2129c0664131e84; affected 00e0f34c616603ba6500f41943cbf89eb4a8a5be before ed3ee0ac4aafda50c2f4381eb973beefeb7879ac; affected 00e0f34c616603ba6500f41943cbf89eb4a8a5be before 6b8d7563c28b8112e6e54abe413b028ef3f8c549; affected 00e0f34c616603ba6500f41943cbf89eb4a8a5be before cb62aa8f04655a4df487913949719c0a1266ed73; affected 00e0f34c616603ba6500f41943cbf89eb4a8a5be before 103c4b13c4f50322910078d1c02f29334a574122 |
| Linux / Linux | affected 2.6.30; unaffected 0 before 2.6.30; unaffected 5.10.271 through 5.10.*; unaffected 5.15.222 through 5.15.*; unaffected 6.1.189 through 6.1.*; unaffected 6.6.158 through 6.6.*; unaffected 6.12.111 through 6.12.*; unaffected 6.18.53 through 6.18.*; unaffected 7.2.7 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
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