From 7d5145d8eb2b9791533ffe4dc003b129b9696c48 Mon Sep 17 00:00:00 2001 From: Matthew Daley Date: Wed, 6 Feb 2013 23:41:36 +0000 Subject: [PATCH] xen/netback: don't leak pages on failure in xen_netbk_tx_check_gop. Signed-off-by: Matthew Daley Reviewed-by: Konrad Rzeszutek Wilk Acked-by: Ian Campbell Acked-by: Jan Beulich Signed-off-by: David S. Miller --- drivers/net/xen-netback/netback.c | 38 +++++++++++-------------------- 1 file changed, 13 insertions(+), 25 deletions(-) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index c2e3336b4f98a8..bf692df966a9d7 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -147,7 +147,8 @@ void xen_netbk_remove_xenvif(struct xenvif *vif) atomic_dec(&netbk->netfront_count); } -static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx); +static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx, + u8 status); static void make_tx_response(struct xenvif *vif, struct xen_netif_tx_request *txp, s8 st); @@ -1007,30 +1008,20 @@ static int xen_netbk_tx_check_gop(struct xen_netbk *netbk, { struct gnttab_copy *gop = *gopp; u16 pending_idx = *((u16 *)skb->data); - struct pending_tx_info *pending_tx_info = netbk->pending_tx_info; - struct xenvif *vif = pending_tx_info[pending_idx].vif; - struct xen_netif_tx_request *txp; struct skb_shared_info *shinfo = skb_shinfo(skb); int nr_frags = shinfo->nr_frags; int i, err, start; /* Check status of header. */ err = gop->status; - if (unlikely(err)) { - pending_ring_idx_t index; - index = pending_index(netbk->pending_prod++); - txp = &pending_tx_info[pending_idx].req; - make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR); - netbk->pending_ring[index] = pending_idx; - xenvif_put(vif); - } + if (unlikely(err)) + xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_ERROR); /* Skip first skb fragment if it is on same page as header fragment. */ start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx); for (i = start; i < nr_frags; i++) { int j, newerr; - pending_ring_idx_t index; pending_idx = frag_get_pending_idx(&shinfo->frags[i]); @@ -1039,16 +1030,12 @@ static int xen_netbk_tx_check_gop(struct xen_netbk *netbk, if (likely(!newerr)) { /* Had a previous error? Invalidate this fragment. */ if (unlikely(err)) - xen_netbk_idx_release(netbk, pending_idx); + xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY); continue; } /* Error on this fragment: respond to client with an error. */ - txp = &netbk->pending_tx_info[pending_idx].req; - make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR); - index = pending_index(netbk->pending_prod++); - netbk->pending_ring[index] = pending_idx; - xenvif_put(vif); + xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_ERROR); /* Not the first error? Preceding frags already invalidated. */ if (err) @@ -1056,10 +1043,10 @@ static int xen_netbk_tx_check_gop(struct xen_netbk *netbk, /* First error: invalidate header and preceding fragments. */ pending_idx = *((u16 *)skb->data); - xen_netbk_idx_release(netbk, pending_idx); + xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY); for (j = start; j < i; j++) { pending_idx = frag_get_pending_idx(&shinfo->frags[j]); - xen_netbk_idx_release(netbk, pending_idx); + xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY); } /* Remember the error: invalidate all subsequent fragments. */ @@ -1093,7 +1080,7 @@ static void xen_netbk_fill_frags(struct xen_netbk *netbk, struct sk_buff *skb) /* Take an extra reference to offset xen_netbk_idx_release */ get_page(netbk->mmap_pages[pending_idx]); - xen_netbk_idx_release(netbk, pending_idx); + xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY); } } @@ -1476,7 +1463,7 @@ static void xen_netbk_tx_submit(struct xen_netbk *netbk) txp->size -= data_len; } else { /* Schedule a response immediately. */ - xen_netbk_idx_release(netbk, pending_idx); + xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY); } if (txp->flags & XEN_NETTXF_csum_blank) @@ -1528,7 +1515,8 @@ static void xen_netbk_tx_action(struct xen_netbk *netbk) xen_netbk_tx_submit(netbk); } -static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx) +static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx, + u8 status) { struct xenvif *vif; struct pending_tx_info *pending_tx_info; @@ -1542,7 +1530,7 @@ static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx) vif = pending_tx_info->vif; - make_tx_response(vif, &pending_tx_info->req, XEN_NETIF_RSP_OKAY); + make_tx_response(vif, &pending_tx_info->req, status); index = pending_index(netbk->pending_prod++); netbk->pending_ring[index] = pending_idx;