From 97099cc6529cdf50af32a496b588d9428c57341f Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Thu, 10 Jan 2019 16:00:19 +0300 Subject: [PATCH] RDMA/bnxt_re: fix a size calculation This is from static analysis not from testing. Depending on the value of rcfw->cmdq_depth, then this might not cause an issue at runtime. The BITS_TO_LONGS() macro tells us how many longs it take to hold a bitmap. In other words, it divides by the number if bits per long and rounds up. Then we want to take that number and multiple by sizeof(long) to get the number of bytes to allocate. The code here does the multiplication first so the rounding up is done in the wrong place. So imagine we want to allocate 1 bit, then "(1 * 8) / 64 = 1" when we round up. But it should be "(1 / 64) * 8 = 8". In other words, because of the rounding difference we might allocate up to "sizeof(long) - 1" bytes fewer than intended. Fixes: 1ac5a4047975 ("RDMA/bnxt_re: Add bnxt_re RoCE driver") Signed-off-by: Dan Carpenter Acked-By: Devesh Sharma Signed-off-by: Jason Gunthorpe --- drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c index 326805461265..742346ea5b0d 100644 --- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c @@ -684,8 +684,7 @@ int bnxt_qplib_enable_rcfw_channel(struct pci_dev *pdev, /* General */ rcfw->seq_num = 0; set_bit(FIRMWARE_FIRST_FLAG, &rcfw->flags); - bmap_size = BITS_TO_LONGS(rcfw->cmdq_depth * - sizeof(unsigned long)); + bmap_size = BITS_TO_LONGS(rcfw->cmdq_depth) * sizeof(unsigned long); rcfw->cmdq_bitmap = kzalloc(bmap_size, GFP_KERNEL); if (!rcfw->cmdq_bitmap) return -ENOMEM; -- 2.11.0