جزئیات آسیب‌پذیری

In the Linux kernel, the following vulnerability has been resolved: net/rds: No shortcut out of RDS_CONN_ERROR RDS connections carry a state "rds_conn_path::cp_state" and transitions from one state to another and are conditional upon an expected state: "rds_conn_path_transition." There is one exception to this conditionality, which is "RDS_CONN_ERROR" that can be enforced by "rds_conn_path_drop" regardless of what state the condition is currently in. But as soon as a connection enters state "RDS_CONN_ERROR", the connection handling code expects it to go through the shutdown-path. The RDS/TCP multipath changes added a shortcut out of "RDS_CONN_ERROR" straight back to "RDS_CONN_CONNECTING" via "rds_tcp_accept_one_path" (e.g. after "rds_tcp_state_change"). A subsequent "rds_tcp_reset_callbacks" can then transition the state to "RDS_CONN_RESETTING" with a shutdown-worker queued. That'll trip up "rds_conn_init_shutdown", which was never adjusted to handle "RDS_CONN_RESETTING" and subsequently drops the connection with the dreaded "DR_INV_CONN_STATE", which leaves "RDS_SHUTDOWN_WORK_QUEUED" on forever. So we do two things here: a) Don't shortcut "RDS_CONN_ERROR", but take the longer path through the shutdown code. b) Add "RDS_CONN_RESETTING" to the expected states in "rds_conn_init_shutdown" so that we won't error out and get stuck, if we ever hit weird state transitions like this again."

• https://git.kernel.org/stable/c/9bcd7c00691a2db9745817d5ea79262a503b135c
• https://git.kernel.org/stable/c/a179ac7be8f5a650d0068040705f4cddd6ca369c
• https://git.kernel.org/stable/c/19e384a7d00d888303a8285977cdf1970c6cccd6
• https://git.kernel.org/stable/c/f0f729bdffb08af32e0f54521b81b8a9e0321f16
• https://git.kernel.org/stable/c/81248b1eb3c5954cc1fc7b33b7c03e34d20cb8c8
• https://git.kernel.org/stable/c/899ef00963ce76f9fc421a7d02335fe4ead6389b
• https://git.kernel.org/stable/c/9ff599a9be784a808c36765086e3db2144aa3b66
• https://git.kernel.org/stable/c/ad22d24be635c6beab6a1fdd3f8b1f3c478d15da