diff mbox series

[rdma-rc,9/9] RDMA/mlx5: Prevent overflow in mmap offset calculations

Message ID 20200212072635.682689-10-leon@kernel.org (mailing list archive)
State Accepted
Delegated to: Jason Gunthorpe
Headers show
Series Fixes for v5.6 | expand

Commit Message

Leon Romanovsky Feb. 12, 2020, 7:26 a.m. UTC 
From: Leon Romanovsky <leonro@mellanox.com>

The cmd and index variables declared as u16 and the result is supposed
to be stored in u64. The C arithmetic rules doesn't promote "(index >>
8) << 16" to be u64 and leaves the end result to be u16.

Fixes: 7be76bef320b ("IB/mlx5: Introduce VAR object and its alloc/destroy methods")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
---
 drivers/infiniband/hw/mlx5/main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index e874d688d040..987bfdcd12a5 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -2283,8 +2283,8 @@  static int mlx5_ib_mmap_offset(struct mlx5_ib_dev *dev,
 
 static u64 mlx5_entry_to_mmap_offset(struct mlx5_user_mmap_entry *entry)
 {
-	u16 cmd = entry->rdma_entry.start_pgoff >> 16;
-	u16 index = entry->rdma_entry.start_pgoff & 0xFFFF;
+	u64 cmd = (entry->rdma_entry.start_pgoff >> 16) & 0xFFFF;
+	u64 index = entry->rdma_entry.start_pgoff & 0xFFFF;
 
 	return (((index >> 8) << 16) | (cmd << MLX5_IB_MMAP_CMD_SHIFT) |
 		(index & 0xFF)) << PAGE_SHIFT;