From ac5b70198adc25c73fba28de4f78adcee8f6be0b 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 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 --- net/core/dev.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'net/core') diff --git a/net/core/dev.c b/net/core/dev.c index dda9d7b9a840..d4362befe7e2 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2382,8 +2382,11 @@ EXPORT_SYMBOL(netdev_set_num_tc); */ 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; @@ -2399,15 +2402,19 @@ 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 From a7dcdf6ea1b264ee7655a8cafe844f06eed3906a Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 20 Feb 2018 23:07:33 +0100 Subject: bpf: clean up unused-variable warning The only user of this variable is inside of an #ifdef, causing a warning without CONFIG_INET: net/core/filter.c: In function '____bpf_sock_ops_cb_flags_set': net/core/filter.c:3382:6: error: unused variable 'val' [-Werror=unused-variable] int val = argval & BPF_SOCK_OPS_ALL_CB_FLAGS; This replaces the #ifdef with a nicer IS_ENABLED() check that makes the code more readable and avoids the warning. Fixes: b13d88072172 ("bpf: Adds field bpf_sock_ops_cb_flags to tcp_sock") Signed-off-by: Arnd Bergmann Signed-off-by: Daniel Borkmann --- net/core/filter.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'net/core') diff --git a/net/core/filter.c b/net/core/filter.c index 08ab4c65a998..0c121adbdbaa 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3381,17 +3381,13 @@ BPF_CALL_2(bpf_sock_ops_cb_flags_set, struct bpf_sock_ops_kern *, bpf_sock, struct sock *sk = bpf_sock->sk; int val = argval & BPF_SOCK_OPS_ALL_CB_FLAGS; - if (!sk_fullsock(sk)) + if (!IS_ENABLED(CONFIG_INET) || !sk_fullsock(sk)) return -EINVAL; -#ifdef CONFIG_INET if (val) tcp_sk(sk)->bpf_sock_ops_cb_flags = val; return argval & (~BPF_SOCK_OPS_ALL_CB_FLAGS); -#else - return -EINVAL; -#endif } static const struct bpf_func_proto bpf_sock_ops_cb_flags_set_proto = { -- cgit v1.2.3 From a5f7add332b4ea6d4b9480971b3b0f5e66466ae9 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 22 Feb 2018 19:45:27 -0800 Subject: net_sched: gen_estimator: fix broken estimators based on percpu stats pfifo_fast got percpu stats lately, uncovering a bug I introduced last year in linux-4.10. I missed the fact that we have to clear our temporary storage before calling __gnet_stats_copy_basic() in the case of percpu stats. Without this fix, rate estimators (tc qd replace dev xxx root est 1sec 4sec pfifo_fast) are utterly broken. Fixes: 1c0d32fde5bd ("net_sched: gen_estimator: complete rewrite of rate estimators") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/gen_estimator.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/core') diff --git a/net/core/gen_estimator.c b/net/core/gen_estimator.c index 0a3f88f08727..98fd12721221 100644 --- a/net/core/gen_estimator.c +++ b/net/core/gen_estimator.c @@ -66,6 +66,7 @@ struct net_rate_estimator { static void est_fetch_counters(struct net_rate_estimator *e, struct gnet_stats_basic_packed *b) { + memset(b, 0, sizeof(*b)); if (e->stats_lock) spin_lock(e->stats_lock); -- cgit v1.2.3