[PATCH 3.10 15/24] net/mlx4_core: Limit count field to 24 bits in qp_alloc_res

From: Greg Kroah-Hartman
Date: Sun Dec 14 2014 - 15:22:46 EST


3.10-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jack Morgenstein <jackm@xxxxxxxxxxxxxxxxxx>

[ Upstream commit 2d5c57d7fbfaa642fb7f0673df24f32b83d9066c ]

Some VF drivers use the upper byte of "param1" (the qp count field)
in mlx4_qp_reserve_range() to pass flags which are used to optimize
the range allocation.

Under the current code, if any of these flags are set, the 32-bit
count field yields a count greater than 2^24, which is out of range,
and this VF fails.

As these flags represent a "best-effort" allocation hint anyway, they may
safely be ignored. Therefore, the PF driver may simply mask out the bits.

Fixes: c82e9aa0a8 "mlx4_core: resource tracking for HCA resources used by guests"
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/resource_tracker.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
+++ b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
@@ -1207,7 +1207,7 @@ static int qp_alloc_res(struct mlx4_dev

switch (op) {
case RES_OP_RESERVE:
- count = get_param_l(&in_param);
+ count = get_param_l(&in_param) & 0xffffff;
align = get_param_h(&in_param);
err = __mlx4_qp_reserve_range(dev, count, align, &base);
if (err)


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