From 063d43326dbc7f47370fda3fcd421503e861f0af Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Thu, 10 Nov 2022 20:24:54 +0800 Subject: [PATCH] tcp: Fix data-races around sysctl_tcp_max_reordering. stable inclusion from stable-v5.10.134 commit 064852663308c801861bd54789d81421fa4c2928 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5ZVR7 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=064852663308c801861bd54789d81421fa4c2928 -------------------------------- [ Upstream commit a11e5b3e7a59fde1a90b0eaeaa82320495cf8cae ] While reading sysctl_tcp_max_reordering, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: dca145ffaa8d ("tcp: allow for bigger reordering level") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Zheng Zengkai Reviewed-by: Wei Li --- net/ipv4/tcp_input.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index ab74acb50936..233fb5d992d4 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1011,7 +1011,7 @@ static void tcp_check_sack_reordering(struct sock *sk, const u32 low_seq, tp->undo_marker ? tp->undo_retrans : 0); #endif tp->reordering = min_t(u32, (metric + mss - 1) / mss, - sock_net(sk)->ipv4.sysctl_tcp_max_reordering); + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_max_reordering)); } /* This exciting event is worth to be remembered. 8) */ @@ -1990,7 +1990,7 @@ static void tcp_check_reno_reordering(struct sock *sk, const int addend) return; tp->reordering = min_t(u32, tp->packets_out + addend, - sock_net(sk)->ipv4.sysctl_tcp_max_reordering); + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_max_reordering)); tp->reord_seen++; NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRENOREORDER); } -- GitLab