This is a note to let you know that I've just added the patch titled net/mlx4: Copy/set only sizeof struct mlx4_eqe bytes to the 4.2-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: net-mlx4-copy-set-only-sizeof-struct-mlx4_eqe-bytes.patch and it can be found in the queue-4.2 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 Tue Nov 17 14:34:38 PST 2015 From: Carol L Soto <clsoto@xxxxxxxxxxxxxxxxxx> Date: Tue, 27 Oct 2015 17:36:20 +0200 Subject: net/mlx4: Copy/set only sizeof struct mlx4_eqe bytes From: Carol L Soto <clsoto@xxxxxxxxxxxxxxxxxx> [ Upstream commit c02b05011fadf8e409e41910217ca689f2fc9d91 ] When doing memcpy/memset of EQEs, we should use sizeof struct mlx4_eqe as the base size and not caps.eqe_size which could be bigger. If caps.eqe_size is bigger than the struct mlx4_eqe then we corrupt data in the master context. When using a 64 byte stride, the memcpy copied over 63 bytes to the slave_eq structure. This resulted in copying over the entire eqe of interest, including its ownership bit -- and also 31 bytes of garbage into the next WQE in the slave EQ -- which did NOT include the ownership bit (and therefore had no impact). However, once the stride is increased to 128, we are overwriting the ownership bits of *three* eqes in the slave_eq struct. This results in an incorrect ownership bit for those eqes, which causes the eq to seem to be full. The issue therefore surfaced only once 128-byte EQEs started being used in SRIOV and (overarchitectures that have 128/256 byte cache-lines such as PPC) - e.g after commit 77507aa249ae "net/mlx4_core: Enable CQE/EQE stride support". Fixes: 08ff32352d6f ('mlx4: 64-byte CQE/EQE support') Signed-off-by: Carol L Soto <clsoto@xxxxxxxxxxxxxxxxxx> Signed-off-by: Jack Morgenstein <jackm@xxxxxxxxxxxxxxxxxx> Signed-off-by: Or Gerlitz <ogerlitz@xxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/mellanox/mlx4/cmd.c | 2 +- drivers/net/ethernet/mellanox/mlx4/eq.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/mellanox/mlx4/cmd.c +++ b/drivers/net/ethernet/mellanox/mlx4/cmd.c @@ -2398,7 +2398,7 @@ int mlx4_multi_func_init(struct mlx4_dev } } - memset(&priv->mfunc.master.cmd_eqe, 0, dev->caps.eqe_size); + memset(&priv->mfunc.master.cmd_eqe, 0, sizeof(struct mlx4_eqe)); priv->mfunc.master.cmd_eqe.type = MLX4_EVENT_TYPE_CMD; INIT_WORK(&priv->mfunc.master.comm_work, mlx4_master_comm_channel); --- a/drivers/net/ethernet/mellanox/mlx4/eq.c +++ b/drivers/net/ethernet/mellanox/mlx4/eq.c @@ -196,7 +196,7 @@ static void slave_event(struct mlx4_dev return; } - memcpy(s_eqe, eqe, dev->caps.eqe_size - 1); + memcpy(s_eqe, eqe, sizeof(struct mlx4_eqe) - 1); s_eqe->slave_id = slave; /* ensure all information is written before setting the ownersip bit */ dma_wmb(); Patches currently in stable-queue which might be from clsoto@xxxxxxxxxxxxxxxxxx are queue-4.2/net-mlx4-copy-set-only-sizeof-struct-mlx4_eqe-bytes.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html