From 0e6f3ef469bbf69ea6840aa4d15dcfc8ce978760 Mon Sep 17 00:00:00 2001 From: Len Baker Date: Sun, 5 Sep 2021 09:49:36 +0200 Subject: [PATCH] net/mlx5: DR, Prefer kcalloc over open coded arithmetic As noted in the "Deprecated Interfaces, Language Features, Attributes, and Conventions" documentation [1], size calculations (especially multiplication) should not be performed in memory allocator (or similar) function arguments due to the risk of them overflowing. This could lead to values wrapping around and a smaller allocation being made than the caller was expecting. Using those allocations could lead to linear overflows of heap memory and other misbehaviors. So, refactor the code a bit to use the purpose specific kcalloc() function instead of the argument size * count in the kzalloc() function. [1] https://www.kernel.org/doc/html/v5.14/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments Signed-off-by: Len Baker Signed-off-by: Saeed Mahameed --- drivers/net/ethernet/mellanox/mlx5/core/steering/dr_action.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_action.c b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_action.c index 5063011..0793684 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_action.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_action.c @@ -854,6 +854,7 @@ mlx5dr_action_create_mult_dest_tbl(struct mlx5dr_domain *dmn, struct mlx5dr_action *action; bool reformat_req = false; u32 num_of_ref = 0; + u32 ref_act_cnt; int ret; int i; @@ -862,11 +863,14 @@ mlx5dr_action_create_mult_dest_tbl(struct mlx5dr_domain *dmn, return NULL; } - hw_dests = kzalloc(sizeof(*hw_dests) * num_of_dests, GFP_KERNEL); + hw_dests = kcalloc(num_of_dests, sizeof(*hw_dests), GFP_KERNEL); if (!hw_dests) return NULL; - ref_actions = kzalloc(sizeof(*ref_actions) * num_of_dests * 2, GFP_KERNEL); + if (unlikely(check_mul_overflow(num_of_dests, 2u, &ref_act_cnt))) + goto free_hw_dests; + + ref_actions = kcalloc(ref_act_cnt, sizeof(*ref_actions), GFP_KERNEL); if (!ref_actions) goto free_hw_dests; -- 2.7.4