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From: Wenchao Hao <haowenchao2@huawei.com>
To: Jason Gunthorpe <jgg@ziepe.ca>, Leon Romanovsky <leon@kernel.org>,
	<linux-rdma@vger.kernel.org>, <linux-kernel@vger.kernel.org>
CC: Wenchao Hao <haowenchao2@huawei.com>, <louhongxiang@huawei.com>
Subject: [PATCH v2] RDMA/restrack: Fix potential invalid address access
Date: Mon, 18 Mar 2024 17:23:20 +0800
Message-ID: <20240318092320.1215235-1-haowenchao2@huawei.com>
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struct rdma_restrack_entry's kern_name was set to KBUILD_MODNAME
in ib_create_cq(), while if the module exited but forgot del this
rdma_restrack_entry, it would cause a invalid address access in
rdma_restrack_clean() when print the owner of this rdma_restrack_entry.

These code is used to help find one forgotten PD release in one of the
ULPs. But it is not needed anymore, so delete them.

Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
---
 drivers/infiniband/core/restrack.c | 51 +-----------------------------
 1 file changed, 1 insertion(+), 50 deletions(-)

diff --git a/drivers/infiniband/core/restrack.c b/drivers/infiniband/core/restrack.c
index 01a499a8b88d..438ed3588175 100644
--- a/drivers/infiniband/core/restrack.c
+++ b/drivers/infiniband/core/restrack.c
@@ -37,22 +37,6 @@ int rdma_restrack_init(struct ib_device *dev)
 	return 0;
 }
 
-static const char *type2str(enum rdma_restrack_type type)
-{
-	static const char * const names[RDMA_RESTRACK_MAX] = {
-		[RDMA_RESTRACK_PD] = "PD",
-		[RDMA_RESTRACK_CQ] = "CQ",
-		[RDMA_RESTRACK_QP] = "QP",
-		[RDMA_RESTRACK_CM_ID] = "CM_ID",
-		[RDMA_RESTRACK_MR] = "MR",
-		[RDMA_RESTRACK_CTX] = "CTX",
-		[RDMA_RESTRACK_COUNTER] = "COUNTER",
-		[RDMA_RESTRACK_SRQ] = "SRQ",
-	};
-
-	return names[type];
-};
-
 /**
  * rdma_restrack_clean() - clean resource tracking
  * @dev:  IB device
@@ -60,47 +44,14 @@ static const char *type2str(enum rdma_restrack_type type)
 void rdma_restrack_clean(struct ib_device *dev)
 {
 	struct rdma_restrack_root *rt = dev->res;
-	struct rdma_restrack_entry *e;
-	char buf[TASK_COMM_LEN];
-	bool found = false;
-	const char *owner;
 	int i;
 
 	for (i = 0 ; i < RDMA_RESTRACK_MAX; i++) {
 		struct xarray *xa = &dev->res[i].xa;
 
-		if (!xa_empty(xa)) {
-			unsigned long index;
-
-			if (!found) {
-				pr_err("restrack: %s", CUT_HERE);
-				dev_err(&dev->dev, "BUG: RESTRACK detected leak of resources\n");
-			}
-			xa_for_each(xa, index, e) {
-				if (rdma_is_kernel_res(e)) {
-					owner = e->kern_name;
-				} else {
-					/*
-					 * There is no need to call get_task_struct here,
-					 * because we can be here only if there are more
-					 * get_task_struct() call than put_task_struct().
-					 */
-					get_task_comm(buf, e->task);
-					owner = buf;
-				}
-
-				pr_err("restrack: %s %s object allocated by %s is not freed\n",
-				       rdma_is_kernel_res(e) ? "Kernel" :
-							       "User",
-				       type2str(e->type), owner);
-			}
-			found = true;
-		}
+		WARN_ON(!xa_empty(xa));
 		xa_destroy(xa);
 	}
-	if (found)
-		pr_err("restrack: %s", CUT_HERE);
-
 	kfree(rt);
 }
 
-- 
2.32.0