svn commit: r299625 - stable/10/sys/kern

[Garrett Cooper]

Author: ngie
Date: Fri May 13 08:44:59 2016
New Revision: 299625
URL: https://svnweb.freebsd.org/changeset/base/299625

Log:
  MFC r298677:
  r298677 (by cem):
  
  subr_mbpool: Don't free bogus pointer in error paths
  
  An mbpool is allocated with a contiguous array of mbpages.  Freeing an
  individual mbpage has never been valid.  Don't do it.
  
  This bug has been present since this code was introduced in r117624 (2003).
  
  CID:		1009687

Modified:
  stable/10/sys/kern/subr_mbpool.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/kern/subr_mbpool.c
==============================================================================
--- stable/10/sys/kern/subr_mbpool.c	Fri May 13 08:42:21 2016	(r299624)
+++ stable/10/sys/kern/subr_mbpool.c	Fri May 13 08:44:59 2016	(r299625)
@@ -210,16 +210,13 @@ mbp_alloc_page(struct mbpool *p)
 	pg = &p->pages[p->npages];
 
 	error = bus_dmamem_alloc(p->dmat, &pg->va, BUS_DMA_NOWAIT, &pg->map);
-	if (error != 0) {
-		free(pg, M_MBPOOL);
+	if (error != 0)
 		return;
-	}
 
 	error = bus_dmamap_load(p->dmat, pg->map, pg->va, p->page_size,
 	    mbp_callback, &pg->phy, 0);
 	if (error != 0) {
 		bus_dmamem_free(p->dmat, pg->va, pg->map);
-		free(pg, M_MBPOOL);
 		return;
 	}