Commit ff5d7497 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller

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: 0df48c26 ("tcp: add tcpi_bytes_acked to tcp_info")
Fixes: 977cb0ec ("tcp: add pacing_rate information into tcp_info")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4f2c6ae5
...@@ -279,6 +279,7 @@ ...@@ -279,6 +279,7 @@
#include <asm/uaccess.h> #include <asm/uaccess.h>
#include <asm/ioctls.h> #include <asm/ioctls.h>
#include <asm/unaligned.h>
#include <net/busy_poll.h> #include <net/busy_poll.h>
int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; 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) ...@@ -2638,6 +2639,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
const struct inet_connection_sock *icsk = inet_csk(sk); const struct inet_connection_sock *icsk = inet_csk(sk);
u32 now = tcp_time_stamp; u32 now = tcp_time_stamp;
unsigned int start; unsigned int start;
u64 rate64;
u32 rate; u32 rate;
memset(info, 0, sizeof(*info)); memset(info, 0, sizeof(*info));
...@@ -2703,15 +2705,17 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) ...@@ -2703,15 +2705,17 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
info->tcpi_total_retrans = tp->total_retrans; info->tcpi_total_retrans = tp->total_retrans;
rate = READ_ONCE(sk->sk_pacing_rate); 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); 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 { do {
start = u64_stats_fetch_begin_irq(&tp->syncp); start = u64_stats_fetch_begin_irq(&tp->syncp);
info->tcpi_bytes_acked = tp->bytes_acked; put_unaligned(tp->bytes_acked, &info->tcpi_bytes_acked);
info->tcpi_bytes_received = tp->bytes_received; put_unaligned(tp->bytes_received, &info->tcpi_bytes_received);
} while (u64_stats_fetch_retry_irq(&tp->syncp, start)); } while (u64_stats_fetch_retry_irq(&tp->syncp, start));
info->tcpi_segs_out = tp->segs_out; info->tcpi_segs_out = tp->segs_out;
info->tcpi_segs_in = tp->segs_in; info->tcpi_segs_in = tp->segs_in;
......
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