From f50fc5f4f3e5f0d2b55cd09c01f3a09d0ddeb9dc Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 18 Jan 2018 19:59:19 -0800 Subject: net: qdisc_pkt_len_init() should be more robust [ Upstream commit 7c68d1a6b4db9012790af7ac0f0fdc0d2083422a ] Without proper validation of DODGY packets, we might very well feed qdisc_pkt_len_init() with invalid GSO packets. tcp_hdrlen() might access out-of-bound data, so let's use skb_header_pointer() and proper checks. Whole story is described in commit d0c081b49137 ("flow_dissector: properly cap thoff field") We have the goal of validating DODGY packets earlier in the stack, so we might very well revert this fix in the future. Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Cc: Jason Wang Reported-by: syzbot+9da69ebac7dddd804552@syzkaller.appspotmail.com Acked-by: Jason Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 3b67c1e5756f..cb58ba15d51e 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2889,10 +2889,21 @@ static void qdisc_pkt_len_init(struct sk_buff *skb) hdr_len = skb_transport_header(skb) - skb_mac_header(skb); /* + transport layer */ - if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) - hdr_len += tcp_hdrlen(skb); - else - hdr_len += sizeof(struct udphdr); + if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) { + const struct tcphdr *th; + struct tcphdr _tcphdr; + + th = skb_header_pointer(skb, skb_transport_offset(skb), + sizeof(_tcphdr), &_tcphdr); + if (likely(th)) + hdr_len += __tcp_hdrlen(th); + } else { + struct udphdr _udphdr; + + if (skb_header_pointer(skb, skb_transport_offset(skb), + sizeof(_udphdr), &_udphdr)) + hdr_len += sizeof(struct udphdr); + } if (shinfo->gso_type & SKB_GSO_DODGY) gso_segs = DIV_ROUND_UP(skb->len - hdr_len, -- cgit v1.2.3 From c1eb38748c284e318699ae2d35b53ef7308fcd9d Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Tue, 12 Dec 2017 11:39:04 -0500 Subject: net: avoid skb_warn_bad_offload on IS_ERR commit 8d74e9f88d65af8bb2e095aff506aa6eac755ada upstream. skb_warn_bad_offload warns when packets enter the GSO stack that require skb_checksum_help or vice versa. Do not warn on arbitrary bad packets. Packet sockets can craft many. Syzkaller was able to demonstrate another one with eth_type games. In particular, suppress the warning when segmentation returns an error, which is for reasons other than checksum offload. See also commit 36c92474498a ("net: WARN if skb_checksum_help() is called on skb requiring segmentation") for context on this warning. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index cb58ba15d51e..389807c1c36f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2598,7 +2598,7 @@ struct sk_buff *__skb_gso_segment(struct sk_buff *skb, segs = skb_mac_gso_segment(skb, features); - if (unlikely(skb_needs_check(skb, tx_path))) + if (unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs))) skb_warn_bad_offload(skb); return segs; -- cgit v1.2.3 From 65fe24fdbbe0f5292d3dd5201a49725d7be21d85 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 12 Feb 2018 21:35:31 -0800 Subject: net: fix race on decreasing number of TX queues [ Upstream commit ac5b70198adc25c73fba28de4f78adcee8f6be0b ] netif_set_real_num_tx_queues() can be called when netdev is up. That usually happens when user requests change of number of channels/rings with ethtool -L. The procedure for changing the number of queues involves resetting the qdiscs and setting dev->num_tx_queues to the new value. When the new value is lower than the old one, extra care has to be taken to ensure ordering of accesses to the number of queues vs qdisc reset. Currently the queues are reset before new dev->num_tx_queues is assigned, leaving a window of time where packets can be enqueued onto the queues going down, leading to a likely crash in the drivers, since most drivers don't check if TX skbs are assigned to an active queue. Fixes: e6484930d7c7 ("net: allocate tx queues in register_netdevice") Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 389807c1c36f..b2f589012c6b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2183,8 +2183,11 @@ EXPORT_SYMBOL(netif_set_xps_queue); */ int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq) { + bool disabling; int rc; + disabling = txq < dev->real_num_tx_queues; + if (txq < 1 || txq > dev->num_tx_queues) return -EINVAL; @@ -2200,15 +2203,19 @@ int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq) if (dev->num_tc) netif_setup_tc(dev, txq); - if (txq < dev->real_num_tx_queues) { + dev->real_num_tx_queues = txq; + + if (disabling) { + synchronize_net(); qdisc_reset_all_tx_gt(dev, txq); #ifdef CONFIG_XPS netif_reset_xps_queues_gt(dev, txq); #endif } + } else { + dev->real_num_tx_queues = txq; } - dev->real_num_tx_queues = txq; return 0; } EXPORT_SYMBOL(netif_set_real_num_tx_queues); -- cgit v1.2.3