From 32f8c816b92e5f7d556ca2f7f17082ce8c8286f0 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Tue, 23 Aug 2022 10:46:46 -0700 Subject: net: Fix data-races around netdev_max_backlog. [ Upstream commit 5dcd08cd19912892586c6082d56718333e2d19db ] While reading netdev_max_backlog, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. While at it, we remove the unnecessary spaces in the doc. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/core/dev.c | 4 ++-- net/core/gro_cells.c | 2 +- net/xfrm/espintcp.c | 2 +- net/xfrm/xfrm_input.c | 2 +- 4 files changed, 5 insertions(+), 5 deletions(-) (limited to 'net') diff --git a/net/core/dev.c b/net/core/dev.c index 2a7d81cd9e2e..e1496e626a53 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4623,7 +4623,7 @@ static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen) struct softnet_data *sd; unsigned int old_flow, new_flow; - if (qlen < (netdev_max_backlog >> 1)) + if (qlen < (READ_ONCE(netdev_max_backlog) >> 1)) return false; sd = this_cpu_ptr(&softnet_data); @@ -4671,7 +4671,7 @@ static int enqueue_to_backlog(struct sk_buff *skb, int cpu, if (!netif_running(skb->dev)) goto drop; qlen = skb_queue_len(&sd->input_pkt_queue); - if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) { + if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) { if (qlen) { enqueue: __skb_queue_tail(&sd->input_pkt_queue, skb); diff --git a/net/core/gro_cells.c b/net/core/gro_cells.c index 541c7a72a28a..21619c70a82b 100644 --- a/net/core/gro_cells.c +++ b/net/core/gro_cells.c @@ -26,7 +26,7 @@ int gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb) cell = this_cpu_ptr(gcells->cells); - if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) { + if (skb_queue_len(&cell->napi_skbs) > READ_ONCE(netdev_max_backlog)) { drop: dev_core_stats_rx_dropped_inc(dev); kfree_skb(skb); diff --git a/net/xfrm/espintcp.c b/net/xfrm/espintcp.c index 82d14eea1b5a..974eb97b77d2 100644 --- a/net/xfrm/espintcp.c +++ b/net/xfrm/espintcp.c @@ -168,7 +168,7 @@ int espintcp_queue_out(struct sock *sk, struct sk_buff *skb) { struct espintcp_ctx *ctx = espintcp_getctx(sk); - if (skb_queue_len(&ctx->out_queue) >= netdev_max_backlog) + if (skb_queue_len(&ctx->out_queue) >= READ_ONCE(netdev_max_backlog)) return -ENOBUFS; __skb_queue_tail(&ctx->out_queue, skb); diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c index 70a8c36f0ba6..b2f4ec9c537f 100644 --- a/net/xfrm/xfrm_input.c +++ b/net/xfrm/xfrm_input.c @@ -782,7 +782,7 @@ int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb, trans = this_cpu_ptr(&xfrm_trans_tasklet); - if (skb_queue_len(&trans->queue) >= netdev_max_backlog) + if (skb_queue_len(&trans->queue) >= READ_ONCE(netdev_max_backlog)) return -ENOBUFS; BUILD_BUG_ON(sizeof(struct xfrm_trans_cb) > sizeof(skb->cb)); -- cgit v1.2.3