RDMA/umem: Fix double dma_buf_unpin in failure path

jira KERNEL-1052
cve CVE-2026-43128
Rebuild_History Non-Buildable kernel-5.14.0-687.10.1.el9_8
commit-author Jacob Moroni <jmoroni@google.com>
commit 104016e

In ib_umem_dmabuf_get_pinned_with_dma_device(), the call to
ib_umem_dmabuf_map_pages() can fail. If this occurs, the dmabuf
is immediately unpinned but the umem_dmabuf->pinned flag is still
set. Then, when ib_umem_release() is called, it calls
ib_umem_dmabuf_revoke() which will call dma_buf_unpin() again.

Fix this by removing the immediate unpin upon failure and just let
the ib_umem_release/revoke path handle it. This also ensures the
proper unmap-unpin unwind ordering if the dmabuf_map_pages call
happened to fail due to dma_resv_wait_timeout (and therefore has
a non-NULL umem_dmabuf->sgt).

Fixes: 1e4df4a ("RDMA/umem: Allow pinned dmabuf umem usage")
	Signed-off-by: Jacob Moroni <jmoroni@google.com>
Link: https://patch.msgid.link/20260224234153.1207849-1-jmoroni@google.com
	Signed-off-by: Leon Romanovsky <leon@kernel.org>
(cherry picked from commit 104016e)
	Signed-off-by: Jonathan Maple <jmaple@ciq.com>

Author: PlaidCat

drivers/infiniband/core/umem_dmabuf.c

@@ -220,13 +220,11 @@ ib_umem_dmabuf_get_pinned_with_dma_device(struct ib_device *device,
 
 	err = ib_umem_dmabuf_map_pages(umem_dmabuf);
 	if (err)
-		goto err_unpin;
+		goto err_release;
 	dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);
 
 	return umem_dmabuf;
 
-err_unpin:
-	dma_buf_unpin(umem_dmabuf->attach);
 err_release:
 	dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);
 	ib_umem_release(&umem_dmabuf->umem);