[PATCH 1/2] RDMA/cxgb4: Cancel reg_work before freeing device on remove

[Fan Wu]

c4iw_uld_state_change() queues reg_work to register the RDMA device.
c4iw_remove() can free ctx->dev while this work is pending or running,
leaving c4iw_register_device() accessing the freed device.

Cancel reg_work before removing the device.  The registration work can
tear down ctx->dev when registration fails, so do not unregister or
deallocate it again in that case.

This issue was found by an in-house static analysis tool.

Fixes: 1c8f1da5d851 ("iw_cxgb4: Fix possible circular dependency locking warning")
Cc: stable@xxxxxxxxxxxxxxx
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@xxxxxxxxxx>
---
 drivers/infiniband/hw/cxgb4/device.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/infiniband/hw/cxgb4/device.c b/drivers/infiniband/hw/cxgb4/device.c
index 102c5646b..c1815972a 100644
--- a/drivers/infiniband/hw/cxgb4/device.c
+++ b/drivers/infiniband/hw/cxgb4/device.c
@@ -951,6 +951,12 @@ void c4iw_dealloc(struct uld_ctx *ctx)
 static void c4iw_remove(struct uld_ctx *ctx)
 {
 	pr_debug("c4iw_dev %p\n", ctx->dev);
+
+	/* c4iw_register_device() may still be using ctx->dev. */
+	cancel_work_sync(&ctx->reg_work);
+	if (!ctx->dev)
+		return;
+
 	debugfs_remove_recursive(ctx->dev->debugfs_root);
 	c4iw_unregister_device(ctx->dev);
 	c4iw_dealloc(ctx);
-- 
2.34.1