This is a note to let you know that I've just added the patch titled RDMA/core: Set sgtable nents when using ib_dma_virt_map_sg() to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rdma-core-set-sgtable-nents-when-using-ib_dma_virt_m.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 8c7f93d071a87932b07e45970e71bd19eaff3490 Author: Logan Gunthorpe <logang@xxxxxxxxxxxx> Date: Wed Oct 13 10:59:42 2021 -0600 RDMA/core: Set sgtable nents when using ib_dma_virt_map_sg() [ Upstream commit ac0fffa0859b8e1e991939663b3ebdd80bf979e6 ] ib_dma_map_sgtable_attrs() should be mapping the sgls and setting nents but the ib_uses_virt_dma() path falls back to ib_dma_virt_map_sg() which will not set the nents in the sgtable. Check the return value (per the map_sg calling convention) and set sgt->nents appropriately on success. Fixes: 79fbd3e1241c ("RDMA: Use the sg_table directly and remove the opencoded version from umem") Link: https://lore.kernel.org/r/20211013165942.89806-1-logang@xxxxxxxxxxxx Reported-by: Bart Van Assche <bvanassche@xxxxxxx> Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx> Tested-by: Bart Van Assche <bvanassche@xxxxxxx> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index 4b50d9a3018a6..4ba642fc8a19a 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -4097,8 +4097,13 @@ static inline int ib_dma_map_sgtable_attrs(struct ib_device *dev, enum dma_data_direction direction, unsigned long dma_attrs) { + int nents; + if (ib_uses_virt_dma(dev)) { - ib_dma_virt_map_sg(dev, sgt->sgl, sgt->orig_nents); + nents = ib_dma_virt_map_sg(dev, sgt->sgl, sgt->orig_nents); + if (!nents) + return -EIO; + sgt->nents = nents; return 0; } return dma_map_sgtable(dev->dma_device, sgt, direction, dma_attrs);