rds_ib_conn_free() unlinks the connection from its device or nodev list under spin_lock_irq()/spin_unlock_irq(). It is not only called from the rmmod path, though: __rds_conn_create() calls trans->conn_free() to undo a lost creation race while it still holds rds_conn_lock, taken with spin_lock_irqsave(). The unconditional spin_unlock_irq() then re-enables interrupts with rds_conn_lock held and leaves them enabled when the caller's spin_unlock_irqrestore() runs, defeating the irqsave the caller relied on. Use the irqsave/irqrestore pair, as rds_tcp_conn_free() and rds_loop_conn_free() already do. Fixes: 745cbccac3fe ("RDS: Rewrite connection cleanup, fixing oops on rmmod") Assisted-by: Claude-Code:claude-fable-5 Signed-off-by: Allison Henderson --- net/rds/ib_cm.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/net/rds/ib_cm.c b/net/rds/ib_cm.c index 4feb0edc360c..118e033229aa 100644 --- a/net/rds/ib_cm.c +++ b/net/rds/ib_cm.c @@ -1271,6 +1271,7 @@ void rds_ib_conn_free(void *arg) { struct rds_ib_connection *ic = arg; spinlock_t *lock_ptr; + unsigned long flags; rdsdebug("ic %p\n", ic); @@ -1278,12 +1279,16 @@ void rds_ib_conn_free(void *arg) * Conn is either on a dev's list or on the nodev list. * A race with shutdown() or connect() would cause problems * (since rds_ibdev would change) but that should never happen. + * + * Callers may hold rds_conn_lock with interrupts disabled + * (__rds_conn_create() undoing a lost creation race), so do not + * re-enable interrupts unconditionally here. */ lock_ptr = ic->rds_ibdev ? &ic->rds_ibdev->spinlock : &ib_nodev_conns_lock; - spin_lock_irq(lock_ptr); + spin_lock_irqsave(lock_ptr, flags); list_del(&ic->ib_node); - spin_unlock_irq(lock_ptr); + spin_unlock_irqrestore(lock_ptr, flags); rds_ib_recv_free_caches(ic); -- 2.25.1