5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Fan Wu <redacted>
commit a7100601aa1a39f799a566acce10db20eaf4b7f2 upstream.
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")
Link: https://patch.msgid.link/r/20260806130128.465460-1-fanwu01@zju.edu.cn (local)
Cc: <redacted>
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <redacted>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/infiniband/hw/cxgb4/device.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/drivers/infiniband/hw/cxgb4/device.c
+++ b/drivers/infiniband/hw/cxgb4/device.c
@@ -953,6 +953,12 @@ 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);