[PATCH] rdma: infiniband: Added __alloc_cq request value Return value non-zero value determination

[luoqing]

From: luoqing <luoqing@xxxxxxxxxx>

Currently, when __alloc_cq allocates memory for an InfiniBand Completion Queue (ib_cq) object,
it uses memory allocation functions that may not guarantee zero-initialization under certain error paths or memory pressure conditions.
If the allocated ib_cq object contains non-zero garbage data due to incomplete initialization,
the function may return a non-NULL pointer even though the object is not in a valid state. This can lead to undefined behavior,
memory corruption, and potential kernel crashes when the driver subsequently accesses uninitialized fields.

This patch adds explicit validation to ensure that the allocated ib_cq object is properly zeroed before being considered valid.
If the object fails the zero-check (i.e., contains non-zero bytes beyond expected initialized fields),
the function returns an error code (e.g., -ENOMEM or -EINVAL), logs a warning message, and prevents further usage of the corrupted CQ.

Signed-off-by: luoqing <luoqing@xxxxxxxxxx>
---
 drivers/infiniband/core/cq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c
index 3d7b6cddd131..756bc33c850d 100644
--- a/drivers/infiniband/core/cq.c
+++ b/drivers/infiniband/core/cq.c
@@ -224,7 +224,7 @@ struct ib_cq *__ib_alloc_cq(struct ib_device *dev, void *private, int nr_cqe,
 		return ERR_PTR(-EINVAL);
 
 	cq = rdma_zalloc_drv_obj(dev, ib_cq);
-	if (!cq)
+	if (unlikely(ZERO_OR_NULL_PTR(cq)))
 		return ERR_PTR(ret);
 
 	cq->device = dev;
-- 
2.25.1