> Subject: [PATCH] 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) Since sizeofbitmap is always a multiple of 64 (pchunk->size is a multiple of 4K block size, and pprm->pble_shift = 6), I am not sure we will hit these issues today. > > 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. Yes nonetheless the patch is good. And we should be using the bitmap_zalloc/free API's rather than open-coding it. Reviewed-by: Shiraz Saleem <shiraz.saleem@xxxxxxxxx>
