This is a note to let you know that I've just added the patch titled IB/mlx4: Fix mlx4_ib_alloc_mr error flow to the 4.4-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: ib-mlx4-fix-mlx4_ib_alloc_mr-error-flow.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Wed Feb 28 16:19:30 CET 2018 From: Leon Romanovsky <leonro@xxxxxxxxxxxx> Date: Sun, 31 Dec 2017 15:33:14 +0200 Subject: IB/mlx4: Fix mlx4_ib_alloc_mr error flow From: Leon Romanovsky <leonro@xxxxxxxxxxxx> [ Upstream commit 5a371cf87e145b86efd32007e46146e78c1eff6d ] ibmr.device is being set only after ib_alloc_mr() is successfully complete. Therefore, in case imlx4_mr_enable() returns with error, the error flow unwinder calls to mlx4_free_priv_pages(), which uses ibmr.device. Such usage causes to NULL dereference oops and to fix it, the IB device should be set in the mr struct earlier stage (e.g. prior to calling mlx4_free_priv_pages()). Fixes: 1b2cd0fc673c ("IB/mlx4: Support the new memory registration API") Signed-off-by: Nitzan Carmi <nitzanc@xxxxxxxxxxxx> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/infiniband/hw/mlx4/mr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/infiniband/hw/mlx4/mr.c +++ b/drivers/infiniband/hw/mlx4/mr.c @@ -424,7 +424,6 @@ struct ib_mr *mlx4_ib_alloc_mr(struct ib goto err_free_mr; mr->max_pages = max_num_sg; - err = mlx4_mr_enable(dev->dev, &mr->mmr); if (err) goto err_free_pl; @@ -435,6 +434,7 @@ struct ib_mr *mlx4_ib_alloc_mr(struct ib return &mr->ibmr; err_free_pl: + mr->ibmr.device = pd->device; mlx4_free_priv_pages(mr); err_free_mr: (void) mlx4_mr_free(dev->dev, &mr->mmr); Patches currently in stable-queue which might be from leonro@xxxxxxxxxxxx are queue-4.4/ib-mlx4-fix-mlx4_ib_alloc_mr-error-flow.patch