From ff5d749772018602c47509bdc0093ff72acd82ec Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 27 Jan 2016 10:52:43 -0800 Subject: tcp: beware of alignments in tcp_get_info() With some combinations of user provided flags in netlink command, it is possible to call tcp_get_info() with a buffer that is not 8-bytes aligned. It does matter on some arches, so we need to use put_unaligned() to store the u64 fields. Current iproute2 package does not trigger this particular issue. Fixes: 0df48c26d841 ("tcp: add tcpi_bytes_acked to tcp_info") Fixes: 977cb0ecf82e ("tcp: add pacing_rate information into tcp_info") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index fd17eec93525..19746b3fcbbe 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -279,6 +279,7 @@ #include #include +#include #include int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; @@ -2638,6 +2639,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) const struct inet_connection_sock *icsk = inet_csk(sk); u32 now = tcp_time_stamp; unsigned int start; + u64 rate64; u32 rate; memset(info, 0, sizeof(*info)); @@ -2703,15 +2705,17 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) info->tcpi_total_retrans = tp->total_retrans; rate = READ_ONCE(sk->sk_pacing_rate); - info->tcpi_pacing_rate = rate != ~0U ? rate : ~0ULL; + rate64 = rate != ~0U ? rate : ~0ULL; + put_unaligned(rate64, &info->tcpi_pacing_rate); rate = READ_ONCE(sk->sk_max_pacing_rate); - info->tcpi_max_pacing_rate = rate != ~0U ? rate : ~0ULL; + rate64 = rate != ~0U ? rate : ~0ULL; + put_unaligned(rate64, &info->tcpi_max_pacing_rate); do { start = u64_stats_fetch_begin_irq(&tp->syncp); - info->tcpi_bytes_acked = tp->bytes_acked; - info->tcpi_bytes_received = tp->bytes_received; + put_unaligned(tp->bytes_acked, &info->tcpi_bytes_acked); + put_unaligned(tp->bytes_received, &info->tcpi_bytes_received); } while (u64_stats_fetch_retry_irq(&tp->syncp, start)); info->tcpi_segs_out = tp->segs_out; info->tcpi_segs_in = tp->segs_in; -- cgit v1.2.1