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>

1 files changed, 2 insertions, 4 deletions

diff --git a/drivers/infiniband/hw/irdma/pble.c b/drivers/infiniband/hw/irdma/pble.c
index da032b952755..fed49da770f3 100644
--- 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;