Messages in this thread Patch in this message | | | From | Kuniyuki Iwashima <> | Subject | [PATCH v1 net 09/16] tcp: Fix a data-race around sysctl_tcp_max_orphans. | Date | Tue, 5 Jul 2022 22:21:23 -0700 |
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While reading sysctl_tcp_max_orphans, it can be changed concurrently. So, we need to add READ_ONCE(). Then we can set proc_dointvec_lockless() as the handler to mark it safe.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> --- net/ipv4/sysctl_net_ipv4.c | 2 +- net/ipv4/tcp.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index cd448cdd3b38..aa5adf136556 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -476,7 +476,7 @@ static struct ctl_table ipv4_table[] = { .data = &sysctl_tcp_max_orphans, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_lockless, }, { .procname = "inet_peer_threshold", diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 028513d3e2a2..2222dfdde316 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2715,7 +2715,8 @@ static void tcp_orphan_update(struct timer_list *unused) static bool tcp_too_many_orphans(int shift) { - return READ_ONCE(tcp_orphan_cache) << shift > sysctl_tcp_max_orphans; + return READ_ONCE(tcp_orphan_cache) << shift > + READ_ONCE(sysctl_tcp_max_orphans); } bool tcp_check_oom(struct sock *sk, int shift) -- 2.30.2
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