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authorEric Dumazet <edumazet@google.com>2016-01-27 21:52:43 +0300
committerDavid S. Miller <davem@davemloft.net>2016-01-29 09:49:30 +0300
commitff5d749772018602c47509bdc0093ff72acd82ec (patch)
tree4f2f716a27d5be037fe8137634b3c72054297e1c /net
parent4f2c6ae5c64c353fb1b0425e4747e5603feadba1 (diff)
downloadlinux-ff5d749772018602c47509bdc0093ff72acd82ec.tar.xz
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 <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp.c12
1 files changed, 8 insertions, 4 deletions
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 <asm/uaccess.h>
#include <asm/ioctls.h>
+#include <asm/unaligned.h>
#include <net/busy_poll.h>
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;