diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-08-01 12:14:33 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-09-29 19:26:25 +0200 |
| commit | 89b2791c0fd6938a1c2124589fe1b0f699d4b0d2 (patch) | |
| tree | df76aface66def0d0fc657163bf2c066d88339bf /tools/perf/util/scripting-engines/trace-event-python.c | |
| parent | c1a6ce0483bbdd9cf3489ef9efc312482344f58c (diff) | |
udp: fix dst races with multicast early demux
[ Upstream commit 10e2eb878f3ca07ac2f05fa5ca5e6c4c9174a27a ]
Multicast dst are not cached. They carry DST_NOCACHE.
As mentioned in commit f8864972126899 ("ipv4: fix dst race in
sk_dst_get()"), these dst need special care before caching them
into a socket.
Caching them is allowed only if their refcnt was not 0, ie we
must use atomic_inc_not_zero()
Also, we must use READ_ONCE() to fetch sk->sk_rx_dst, as mentioned
in commit d0c294c53a771 ("tcp: prevent fetching dst twice in early demux
code")
Fixes: 421b3885bf6d ("udp: ipv4: Add udp early demux")
Tested-by: Gregory Hoggarth <Gregory.Hoggarth@alliedtelesis.co.nz>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Gregory Hoggarth <Gregory.Hoggarth@alliedtelesis.co.nz>
Reported-by: Alex Gartrell <agartrell@fb.com>
Cc: Michal Kubeček <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/perf/util/scripting-engines/trace-event-python.c')
0 files changed, 0 insertions, 0 deletions