svn commit: r299626 - stable/9/sys/kern

[Garrett Cooper]

Author: ngie
Date: Fri May 13 08:46:13 2016
New Revision: 299626
URL: https://svnweb.freebsd.org/changeset/base/299626

Log:
  MFstable/10 r299625:
  
  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/9/sys/kern/subr_mbpool.c
Directory Properties:
  stable/9/   (props changed)
  stable/9/sys/   (props changed)

Modified: stable/9/sys/kern/subr_mbpool.c
==============================================================================
--- stable/9/sys/kern/subr_mbpool.c	Fri May 13 08:44:59 2016	(r299625)
+++ stable/9/sys/kern/subr_mbpool.c	Fri May 13 08:46:13 2016	(r299626)
@@ -209,16 +209,13 @@ 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;
 	}