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net/mlx4_core: Adjust allocation type for buddy->bits

PATCH Applied Kees Cook 4 participants 4 messages Apr 26, 2025 – Apr 29, 2025

Subsystems (4)
Networking Network drivers InfiniBand Mellanox MLX4 core VPI driver
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Kees Cook

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#0 lore raw

PATCH 1/1 net/mlx4_core: Adjust allocation type for buddy->bits

In preparation for making the kmalloc family of allocators type aware, we need to make sure that the returned type from the allocation matches the type of the variable being assigned. (Before, the allocator would always return "void *", which can be implicitly cast to any pointer type.)

The assigned type is "unsigned long **", but the returned type will be "long **". These are the same size allocation (pointer size) but the types do not match. Adjust the allocation type to match the assignment.

Signed-off-by Kees Cook <[email protected]>

---
Cc: Tariq Toukan <[email protected]>
Cc: Andrew Lunn <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>

---
 drivers/net/ethernet/mellanox/mlx4/mr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/net/ethernet/mellanox/mlx4/mr.c +1 -1
index d7444782bfdd..698a5d1f0d7e 100644
@@ -106,7 +106,7 @@ static int mlx4_buddy_init(struct mlx4_buddy *buddy, int max_order)
 	buddy->max_order = max_order;
 	spin_lock_init(&buddy->lock);
 
-	buddy->bits = kcalloc(buddy->max_order + 1, sizeof(long *),
+	buddy->bits = kcalloc(buddy->max_order + 1, sizeof(*buddy->bits),
 			      GFP_KERNEL);
 	buddy->num_free = kcalloc(buddy->max_order + 1, sizeof(*buddy->num_free),
 				  GFP_KERNEL);
Signature · 1 line
2.34.1
reviewer Reviewed-by on v1 1/1
#1 lore raw
Quoted 10 lines · Kees Cook

In preparation for making the kmalloc family of allocators type aware, we need to make sure that the returned type from the allocation matches the type of the variable being assigned. (Before, the allocator would always return "void *", which can be implicitly cast to any pointer type.)

The assigned type is "unsigned long **", but the returned type will be "long **". These are the same size allocation (pointer size) but the types do not match. Adjust the allocation type to match the assignment.

Signed-off-by Kees Cook <[email protected]>
Reviewed-by Simon Horman <[email protected]>
Reviewed-by on v1 1/1
#2 lore raw
In reply to Kees Cook
Quoted 28 lines · Kees Cook

In preparation for making the kmalloc family of allocators type aware, we need to make sure that the returned type from the allocation matches the type of the variable being assigned. (Before, the allocator would always return "void *", which can be implicitly cast to any pointer type.)

The assigned type is "unsigned long **", but the returned type will be "long **". These are the same size allocation (pointer size) but the types do not match. Adjust the allocation type to match the assignment.

Signed-off-by Kees Cook <[email protected]>

---
Cc: Tariq Toukan <[email protected]>
Cc: Andrew Lunn <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>

---
  drivers/net/ethernet/mellanox/mlx4/mr.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)
drivers/net/ethernet/mellanox/mlx4/mr.c +0 -0
index d7444782bfdd..698a5d1f0d7e 100644

drivers/net/ethernet/mellanox/mlx4/mr.c static int mlx4_buddy_init(struct mlx4_buddy *buddy, int max_order) · line 112

Quoted 8 lines
drivers/net/ethernet/mellanox/mlx4/mr.c +1 -1
@@ -106,7 +106,7 @@ static int mlx4_buddy_init(struct mlx4_buddy *buddy, int max_order)
  	buddy->max_order = max_order;
  	spin_lock_init(&buddy->lock);
 
-	buddy->bits = kcalloc(buddy->max_order + 1, sizeof(long *),
+	buddy->bits = kcalloc(buddy->max_order + 1, sizeof(*buddy->bits),
  			      GFP_KERNEL);
  	buddy->num_free = kcalloc(buddy->max_order + 1, sizeof(*buddy->num_free),
  				  GFP_KERNEL);
Reviewed-by Tariq Toukan <[email protected]>

Thanks.

CI Applied
#3 lore raw
In reply to Kees Cook
This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <[email protected]>:

Hello:

This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <[email protected]>:

Quoted 10 lines · On Fri, 25 Apr 2025 23:07:58 -0700 you wrote:

In preparation for making the kmalloc family of allocators type aware, we need to make sure that the returned type from the allocation matches the type of the variable being assigned. (Before, the allocator would always return "void *", which can be implicitly cast to any pointer type.)

The assigned type is "unsigned long **", but the returned type will be "long **". These are the same size allocation (pointer size) but the types do not match. Adjust the allocation type to match the assignment.

[...]

Here is the summary with links:
- net/mlx4_core: Adjust allocation type for buddy->bits

    https://git.kernel.org/netdev/net-next/c/01cbf838c775

You are awesome, thank you!

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