RDMA/irdma: Fix a potential memory allocation issue in 'irdma_prm_add_pble_mem()'

'pchunk->bitmapbuf' is a bitmap. Its size (in number of bits) is stored in
'pchunk->sizeofbitmap'.

When it is allocated, the size (in bytes) is computed by:
   size_in_bits >> 3

There are 2 issues (numbers bellow assume that longs are 64 bits):
   - there is no guarantee here that 'pchunk->bitmapmem.size' is modulo
     BITS_PER_LONG but bitmaps are stored as longs
     (sizeofbitmap=8 bits will only allocate 1 byte, instead of 8 (1 long))

   - the number of bytes is computed with a shift, not a round up, so we
     may allocate less memory than needed
     (sizeofbitmap=65 bits will only allocate 8 bytes (i.e. 1 long), when 2
     longs are needed = 16 bytes)

Fix both issues by using 'bitmap_zalloc()' and remove the useless
'bitmapmem' from 'struct irdma_chunk'.

While at it, remove some useless NULL test before calling
kfree/bitmap_free.

Fixes: 915cc7ac0f8e ("RDMA/irdma: Add miscellaneous utility definitions")
Link: https://lore.kernel.org/r/5e670b640508e14b1869c3e8e4fb970d78cbe997.1638692171.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/infiniband/hw/irdma/pble.c b/drivers/infiniband/hw/irdma/pble.c
index da032b9..fed49da 100644 (file)
--- a/drivers/infiniband/hw/irdma/pble.c
+++ b/drivers/infiniband/hw/irdma/pble.c
@@ -25,8 +25,7 @@ void irdma_destroy_pble_prm(struct irdma_hmc_pble_rsrc *pble_rsrc)
                list_del(&chunk->list);
                if (chunk->type == PBLE_SD_PAGED)
                        irdma_pble_free_paged_mem(chunk);
-               if (chunk->bitmapbuf)
-                       kfree(chunk->bitmapmem.va);
+               bitmap_free(chunk->bitmapbuf);
                kfree(chunk->chunkmem.va);
        }
 }
@@ -299,8 +298,7 @@ add_pble_prm(struct irdma_hmc_pble_rsrc *pble_rsrc)
        return 0;
 
 error:
-       if (chunk->bitmapbuf)
-               kfree(chunk->bitmapmem.va);
+       bitmap_free(chunk->bitmapbuf);
        kfree(chunk->chunkmem.va);
 
        return ret_code;

diff --git a/drivers/infiniband/hw/irdma/pble.h b/drivers/infiniband/hw/irdma/pble.h
index e1b3b81..aa20827 100644 (file)
--- a/drivers/infiniband/hw/irdma/pble.h
+++ b/drivers/infiniband/hw/irdma/pble.h
@@ -78,7 +78,6 @@ struct irdma_chunk {
        u32 pg_cnt;
        enum irdma_alloc_type type;
        struct irdma_sc_dev *dev;
-       struct irdma_virt_mem bitmapmem;
        struct irdma_virt_mem chunkmem;
 };
 

diff --git a/drivers/infiniband/hw/irdma/utils.c b/drivers/infiniband/hw/irdma/utils.c
index 8b42c43..981107b 100644 (file)
--- a/drivers/infiniband/hw/irdma/utils.c
+++ b/drivers/infiniband/hw/irdma/utils.c
@@ -2239,15 +2239,10 @@ enum irdma_status_code irdma_prm_add_pble_mem(struct irdma_pble_prm *pprm,
 
        sizeofbitmap = (u64)pchunk->size >> pprm->pble_shift;
 
-       pchunk->bitmapmem.size = sizeofbitmap >> 3;
-       pchunk->bitmapmem.va = kzalloc(pchunk->bitmapmem.size, GFP_KERNEL);
-
-       if (!pchunk->bitmapmem.va)
+       pchunk->bitmapbuf = bitmap_zalloc(sizeofbitmap, GFP_KERNEL);
+       if (!pchunk->bitmapbuf)
                return IRDMA_ERR_NO_MEMORY;
 
-       pchunk->bitmapbuf = pchunk->bitmapmem.va;
-       bitmap_zero(pchunk->bitmapbuf, sizeofbitmap);
-
        pchunk->sizeofbitmap = sizeofbitmap;
        /* each pble is 8 bytes hence shift by 3 */
        pprm->total_pble_alloc += pchunk->size >> 3;