Ian Campbell
2013-Feb-07 09:41 UTC
[PATCH v2 3/4] xen/netback: free already allocated memory on failure in xen_netbk_get_requests
Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: <stable@vger.kernel.org> # 3.0+ --- v2: s/reponses/responses/ (blp) & fixup block comment style (DaveM) --- drivers/net/xen-netback/netback.c | 13 ++++++++++++- 1 files changed, 12 insertions(+), 1 deletions(-) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index bf692df..dcb2d4d 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -978,7 +978,7 @@ static struct gnttab_copy *xen_netbk_get_requests(struct xen_netbk *netbk, pending_idx = netbk->pending_ring[index]; page = xen_netbk_alloc_page(netbk, skb, pending_idx); if (!page) - return NULL; + goto err; gop->source.u.ref = txp->gref; gop->source.domid = vif->domid; @@ -1000,6 +1000,17 @@ static struct gnttab_copy *xen_netbk_get_requests(struct xen_netbk *netbk, } return gop; +err: + /* Unwind, freeing all pages and sending error responses. */ + while (i-- > start) { + xen_netbk_idx_release(netbk, frag_get_pending_idx(&frags[i]), + XEN_NETIF_RSP_ERROR); + } + /* The head too, if necessary. */ + if (start) + xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_ERROR); + + return NULL; } static int xen_netbk_tx_check_gop(struct xen_netbk *netbk, -- 1.7.2.5