When rdma_destroy_id() and cma_iw_handler() race, struct rdma_id_private *id_priv can be destroyed during cma_iw_handler call. This causes "BUG: KASAN: slab-use-after-free" at mutex_lock() in cma_iw_handler(). To prevent the destroy of id_priv, keep its reference count by calling cma_id_get() and cma_id_put() at start and end of cma_iw_handler(). Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- The BUG KASAN was observed with blktests at test cases nvme/030 or nvme/031, using SIW transport [1]. To reproduce it, it is required to repeat the test cases from 30 to 50 times on my test system. [1] https://lore.kernel.org/linux-block/rsmmxrchy6voi5qhl4irss5sprna3f5owkqtvybxglcv2pnylm@xmrnpfu3tfpe/ drivers/infiniband/core/cma.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 93a1c48d0c32..c5267d9bb184 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -2477,6 +2477,7 @@ static int cma_iw_handler(struct iw_cm_id *iw_id, struct iw_cm_event *iw_event) struct sockaddr *laddr = (struct sockaddr *)&iw_event->local_addr; struct sockaddr *raddr = (struct sockaddr *)&iw_event->remote_addr; + cma_id_get(id_priv); mutex_lock(&id_priv->handler_mutex); if (READ_ONCE(id_priv->state) != RDMA_CM_CONNECT) goto out; @@ -2524,12 +2525,14 @@ static int cma_iw_handler(struct iw_cm_id *iw_id, struct iw_cm_event *iw_event) if (ret) { /* Destroy the CM ID by returning a non-zero value. */ id_priv->cm_id.iw = NULL; + cma_id_put(id_priv); destroy_id_handler_unlock(id_priv); return ret; } out: mutex_unlock(&id_priv->handler_mutex); + cma_id_put(id_priv); return ret; } -- 2.40.1
