[PATCH 6.18 440/752] RDMA/umem: Fix double dma_buf_unpin in failure path

Sasha Levin
2026-02-28T17:54:17Z

From: Jacob Moroni <jmoroni@google.com>

[ Upstream commit 104016eb671e19709721c1b0048dd912dc2e96be ]

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: 1e4df4a21c5a ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/core/umem_dmabuf.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/infiniband/core/umem_dmabuf.c b/drivers/infiniband/core/umem_dmabuf.c
index 0ec2e4120cc94..17b16fe0e49d9 100644
--- a/drivers/infiniband/core/umem_dmabuf.c
+++ b/drivers/infiniband/core/umem_dmabuf.c
@@ -221,13 +221,11 @@ 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);
--
2.51.0