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| author | Eric Dumazet <edumazet@google.com> | 2022-08-30 11:56:55 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-08-31 19:56:48 -0700 |
| commit | 8c70521238b7863c2af607e20bcba20f974c969b (patch) | |
| tree | 3da2f1ce9a4300c7be768683ae8297bd8d342e7b /net | |
| parent | 52267ce25f60f37ae40ccbca0b21328ebae5ae75 (diff) | |
| download | linux-8c70521238b7863c2af607e20bcba20f974c969b.tar.gz linux-8c70521238b7863c2af607e20bcba20f974c969b.tar.bz2 linux-8c70521238b7863c2af607e20bcba20f974c969b.zip | |
tcp: annotate data-race around challenge_timestamp
challenge_timestamp can be read an written by concurrent threads.
This was expected, but we need to annotate the race to avoid potential issues.
Following patch moves challenge_timestamp and challenge_count
to per-netns storage to provide better isolation.
Fixes: 354e4aa391ed ("tcp: RFC 5961 5.2 Blind Data Injection Attack Mitigation")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_input.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index ab5f0ea166f1..c184e15397a2 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3629,11 +3629,11 @@ static void tcp_send_challenge_ack(struct sock *sk) /* Then check host-wide RFC 5961 rate limit. */ now = jiffies / HZ; - if (now != challenge_timestamp) { + if (now != READ_ONCE(challenge_timestamp)) { u32 ack_limit = READ_ONCE(net->ipv4.sysctl_tcp_challenge_ack_limit); u32 half = (ack_limit + 1) >> 1; - challenge_timestamp = now; + WRITE_ONCE(challenge_timestamp, now); WRITE_ONCE(challenge_count, half + prandom_u32_max(ack_limit)); } count = READ_ONCE(challenge_count); |