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From 524fc5ee3edabf137b7b27c343f88189c35ddb5b Mon Sep 17 00:00:00 2001 |
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From: Sasha Levin <sashal@kernel.org> |
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Date: Tue, 23 Aug 2022 10:46:46 -0700 |
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Subject: net: Fix data-races around netdev_max_backlog. |
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|
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From: Kuniyuki Iwashima <kuniyu@amazon.com> |
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|
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[ Upstream commit 5dcd08cd19912892586c6082d56718333e2d19db ] |
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|
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While reading netdev_max_backlog, it can be changed concurrently. |
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Thus, we need to add READ_ONCE() to its readers. |
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|
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While at it, we remove the unnecessary spaces in the doc. |
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|
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Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") |
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Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> |
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Signed-off-by: David S. Miller <davem@davemloft.net> |
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Signed-off-by: Sasha Levin <sashal@kernel.org> |
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--- |
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Documentation/admin-guide/sysctl/net.rst | 2 +- |
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net/core/dev.c | 4 ++-- |
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net/core/gro_cells.c | 2 +- |
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net/xfrm/espintcp.c | 2 +- |
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net/xfrm/xfrm_input.c | 2 +- |
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5 files changed, 6 insertions(+), 6 deletions(-) |
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|
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diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst |
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index fcd650bdbc7e2..01d9858197832 100644 |
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--- a/Documentation/admin-guide/sysctl/net.rst |
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+++ b/Documentation/admin-guide/sysctl/net.rst |
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@@ -271,7 +271,7 @@ poll cycle or the number of packets processed reaches netdev_budget. |
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netdev_max_backlog |
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------------------ |
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|
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-Maximum number of packets, queued on the INPUT side, when the interface |
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+Maximum number of packets, queued on the INPUT side, when the interface |
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receives packets faster than kernel can process them. |
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|
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netdev_rss_key |
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diff --git a/net/core/dev.c b/net/core/dev.c |
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index 2a7d81cd9e2ea..e1496e626a532 100644 |
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--- a/net/core/dev.c |
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+++ b/net/core/dev.c |
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@@ -4623,7 +4623,7 @@ static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen) |
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struct softnet_data *sd; |
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unsigned int old_flow, new_flow; |
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|
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- if (qlen < (netdev_max_backlog >> 1)) |
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+ if (qlen < (READ_ONCE(netdev_max_backlog) >> 1)) |
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return false; |
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|
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sd = this_cpu_ptr(&softnet_data); |
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@@ -4671,7 +4671,7 @@ static int enqueue_to_backlog(struct sk_buff *skb, int cpu, |
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if (!netif_running(skb->dev)) |
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goto drop; |
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qlen = skb_queue_len(&sd->input_pkt_queue); |
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- if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) { |
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+ if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) { |
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if (qlen) { |
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enqueue: |
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__skb_queue_tail(&sd->input_pkt_queue, skb); |
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diff --git a/net/core/gro_cells.c b/net/core/gro_cells.c |
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index 541c7a72a28a4..21619c70a82b7 100644 |
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--- a/net/core/gro_cells.c |
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+++ b/net/core/gro_cells.c |
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@@ -26,7 +26,7 @@ int gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb) |
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|
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cell = this_cpu_ptr(gcells->cells); |
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|
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- if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) { |
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+ if (skb_queue_len(&cell->napi_skbs) > READ_ONCE(netdev_max_backlog)) { |
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drop: |
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dev_core_stats_rx_dropped_inc(dev); |
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kfree_skb(skb); |
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diff --git a/net/xfrm/espintcp.c b/net/xfrm/espintcp.c |
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index 82d14eea1b5ad..974eb97b77d22 100644 |
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--- a/net/xfrm/espintcp.c |
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+++ b/net/xfrm/espintcp.c |
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@@ -168,7 +168,7 @@ int espintcp_queue_out(struct sock *sk, struct sk_buff *skb) |
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{ |
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struct espintcp_ctx *ctx = espintcp_getctx(sk); |
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|
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- if (skb_queue_len(&ctx->out_queue) >= netdev_max_backlog) |
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+ if (skb_queue_len(&ctx->out_queue) >= READ_ONCE(netdev_max_backlog)) |
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return -ENOBUFS; |
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|
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__skb_queue_tail(&ctx->out_queue, skb); |
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diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c |
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index 70a8c36f0ba6e..b2f4ec9c537f0 100644 |
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--- a/net/xfrm/xfrm_input.c |
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+++ b/net/xfrm/xfrm_input.c |
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@@ -782,7 +782,7 @@ int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb, |
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|
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trans = this_cpu_ptr(&xfrm_trans_tasklet); |
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|
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- if (skb_queue_len(&trans->queue) >= netdev_max_backlog) |
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+ if (skb_queue_len(&trans->queue) >= READ_ONCE(netdev_max_backlog)) |
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return -ENOBUFS; |
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|
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BUILD_BUG_ON(sizeof(struct xfrm_trans_cb) > sizeof(skb->cb)); |
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-- |
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2.35.1 |
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