From: Sharath Srinivasan When rds_send_xmit() picks the next message off cp_send_queue it takes its own reference with rds_message_addref(). If the message then hits the never-retransmit check (RDS_MSG_FLUSH, or an RDMA op that was already retransmitted), it is moved to the local to_be_dropped list and that reference is dropped after the batch. However, if RDS_MSG_ON_CONN has already been cleared - e.g. a racing rds_send_drop_to() or rds_send_path_reset() took the message off the connection lists - the message is not added to to_be_dropped and the reference taken above is never dropped: cp_xmit_rm has not been set at this point, so the loop simply abandons rm and the rds_message (and everything it pins: pages, MRs, notifiers) leaks after an RDMA error. Drop the reference directly in that case. This mirrors Oracle UEK commit "net/rds: fix rds_message memleak in rds_send_xmit". Fixes: 2ad8099b58f2 ("RDS: rds_send_xmit() locking/irq fixes") Signed-off-by: Gerd Rausch Signed-off-by: Sharath Srinivasan [achender: port to net-next; update commit message, checkpatch nits] Assisted-by: Claude-Code:claude-fable-5 Signed-off-by: Allison Henderson --- net/rds/send.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/net/rds/send.c b/net/rds/send.c index 68be1bf0e0adf..7e48f64dfaa67 100644 --- a/net/rds/send.c +++ b/net/rds/send.c @@ -339,9 +339,21 @@ int rds_send_xmit(struct rds_conn_path *cp) (rm->rdma.op_active && test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags))) { spin_lock_irqsave(&cp->cp_lock, flags); - if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) - list_move(&rm->m_conn_item, &to_be_dropped); - spin_unlock_irqrestore(&cp->cp_lock, flags); + if (test_and_clear_bit(RDS_MSG_ON_CONN, + &rm->m_flags)) { + /* our ref is put after the batch */ + list_move(&rm->m_conn_item, + &to_be_dropped); + spin_unlock_irqrestore(&cp->cp_lock, + flags); + } else { + /* already off the conn list; drop + * the ref taken above ourselves + */ + spin_unlock_irqrestore(&cp->cp_lock, + flags); + rds_message_put(rm); + } continue; } -- 2.25.1