lkml.org 
[lkml]   [2021]   [Dec]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] RDMA/irdma: Fix a potential memory allocation issue in 'irdma_prm_add_pble_mem()'
On Sun, Dec 05, 2021 at 09:17:24AM +0100, Christophe JAILLET wrote:
> @@ -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);

Thanks for removing the "chunk->bitmapbuf = chunk->bitmapmem.va;" stuff.
It was really confusing. The kfree(chunk->chunkmem.va) is equivalent to
kfree(chunk). A good rule of thumb is that when you have one error:
label to free everything then it's normally going to be buggy.

drivers/infiniband/hw/irdma/pble.c
281 pble_rsrc->next_fpm_addr += chunk->size;
282 ibdev_dbg(to_ibdev(dev),
283 "PBLE: next_fpm_addr = %llx chunk_size[%llu] = 0x%llx\n",
284 pble_rsrc->next_fpm_addr, chunk->size, chunk->size);
285 pble_rsrc->unallocated_pble -= (u32)(chunk->size >> 3);
286 list_add(&chunk->list, &pble_rsrc->pinfo.clist);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
"chunk" added to the "->pinfo.clist" list.

287 sd_reg_val = (sd_entry_type == IRDMA_SD_TYPE_PAGED) ?
288 sd_entry->u.pd_table.pd_page_addr.pa :
289 sd_entry->u.bp.addr.pa;
290
291 if (!sd_entry->valid) {
292 ret_code = irdma_hmc_sd_one(dev, hmc_info->hmc_fn_id, sd_reg_val,
293 idx->sd_idx, sd_entry->entry_type, true);
294 if (ret_code)
295 goto error;
^^^^^^^^^^^

296 }
297
298 sd_entry->valid = true;
299 return 0;
300
301 error:
302 if (chunk->bitmapbuf)
303 kfree(chunk->bitmapmem.va);
304 kfree(chunk->chunkmem.va);
^^^^^^^^^^^^^^^^^^^^^^^^^^
kfree(chunk) will lead to a use after free because it's still on the
list.

305
306 return ret_code;
307 }

regards,
dan carpenter

\
 
 \ /
  Last update: 2021-12-07 14:15    [W:0.065 / U:0.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site