From c01003c20563d1e75ec9828d21743919d2b43977 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Thu, 29 Mar 2007 11:46:52 -0700 Subject: [PATCH] [IFB]: Fix crash on input device removal The input_device pointer is not refcounted, which means the device may disappear while packets are queued, causing a crash when ifb passes packets with a stale skb->dev pointer to netif_rx(). Fix by storing the interface index instead and do a lookup where neccessary. Signed-off-by: Patrick McHardy Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller --- drivers/net/ifb.c | 35 +++++++++++++---------------------- include/linux/skbuff.h | 5 +++-- include/net/pkt_cls.h | 7 +++++-- net/core/dev.c | 8 ++++---- net/core/skbuff.c | 2 +- net/sched/act_mirred.c | 2 +- 6 files changed, 27 insertions(+), 32 deletions(-) diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c index ca2b21f9d44..07b4c0d7a75 100644 --- a/drivers/net/ifb.c +++ b/drivers/net/ifb.c @@ -96,17 +96,24 @@ static void ri_tasklet(unsigned long dev) skb->tc_verd = SET_TC_NCLS(skb->tc_verd); stats->tx_packets++; stats->tx_bytes +=skb->len; + + skb->dev = __dev_get_by_index(skb->iif); + if (!skb->dev) { + dev_kfree_skb(skb); + stats->tx_dropped++; + break; + } + skb->iif = _dev->ifindex; + if (from & AT_EGRESS) { dp->st_rx_frm_egr++; dev_queue_xmit(skb); } else if (from & AT_INGRESS) { - dp->st_rx_frm_ing++; + skb_pull(skb, skb->dev->hard_header_len); netif_rx(skb); - } else { - dev_kfree_skb(skb); - stats->tx_dropped++; - } + } else + BUG(); } if (netif_tx_trylock(_dev)) { @@ -157,26 +164,10 @@ static int ifb_xmit(struct sk_buff *skb, struct net_device *dev) stats->rx_packets++; stats->rx_bytes+=skb->len; - if (!from || !skb->input_dev) { -dropped: + if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->iif) { dev_kfree_skb(skb); stats->rx_dropped++; return ret; - } else { - /* - * note we could be going - * ingress -> egress or - * egress -> ingress - */ - skb->dev = skb->input_dev; - skb->input_dev = dev; - if (from & AT_INGRESS) { - skb_pull(skb, skb->dev->hard_header_len); - } else { - if (!(from & AT_EGRESS)) { - goto dropped; - } - } } if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) { diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 4ff3940210d..82f43ad478c 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -188,7 +188,7 @@ enum { * @sk: Socket we are owned by * @tstamp: Time we arrived * @dev: Device we arrived on/are leaving by - * @input_dev: Device we arrived on + * @iif: ifindex of device we arrived on * @h: Transport layer header * @nh: Network layer header * @mac: Link layer header @@ -235,7 +235,8 @@ struct sk_buff { struct sock *sk; struct skb_timeval tstamp; struct net_device *dev; - struct net_device *input_dev; + int iif; + /* 4 byte hole on 64 bit*/ union { struct tcphdr *th; diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h index b902d24a325..02647fe3d74 100644 --- a/include/net/pkt_cls.h +++ b/include/net/pkt_cls.h @@ -352,10 +352,13 @@ tcf_change_indev(struct tcf_proto *tp, char *indev, struct rtattr *indev_tlv) static inline int tcf_match_indev(struct sk_buff *skb, char *indev) { + struct net_device *dev; + if (indev[0]) { - if (!skb->input_dev) + if (!skb->iif) return 0; - if (strcmp(indev, skb->input_dev->name)) + dev = __dev_get_by_index(skb->iif); + if (!dev || strcmp(indev, dev->name)) return 0; } diff --git a/net/core/dev.c b/net/core/dev.c index 5984b55311a..d44b8f1964f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1741,8 +1741,8 @@ static int ing_filter(struct sk_buff *skb) if (dev->qdisc_ingress) { __u32 ttl = (__u32) G_TC_RTTL(skb->tc_verd); if (MAX_RED_LOOP < ttl++) { - printk(KERN_WARNING "Redir loop detected Dropping packet (%s->%s)\n", - skb->input_dev->name, skb->dev->name); + printk(KERN_WARNING "Redir loop detected Dropping packet (%d->%d)\n", + skb->iif, skb->dev->ifindex); return TC_ACT_SHOT; } @@ -1775,8 +1775,8 @@ int netif_receive_skb(struct sk_buff *skb) if (!skb->tstamp.off_sec) net_timestamp(skb); - if (!skb->input_dev) - skb->input_dev = skb->dev; + if (!skb->iif) + skb->iif = skb->dev->ifindex; orig_dev = skb_bond(skb); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 702fa8f0874..87573ae35b0 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -496,7 +496,7 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask) n->tc_verd = SET_TC_VERD(skb->tc_verd,0); n->tc_verd = CLR_TC_OK2MUNGE(n->tc_verd); n->tc_verd = CLR_TC_MUNGED(n->tc_verd); - C(input_dev); + C(iif); #endif skb_copy_secmark(n, skb); #endif diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index 68f26cb278f..3e93683e9ab 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -198,7 +198,7 @@ bad_mirred: skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at); skb2->dev = dev; - skb2->input_dev = skb->dev; + skb2->iif = skb->dev->ifindex; dev_queue_xmit(skb2); spin_unlock(&m->tcf_lock); return m->tcf_action; -- 2.20.1