mirror of
https://github.com/rd-stuffs/msm-4.14.git
synced 2025-02-20 11:45:48 +08:00
d1e37288c9
There is a corner case in which udp packets belonging to a same flow are hashed to different socket when hslot->count changes from 10 to 11: 1) When hslot->count <= 10, __udp_lib_lookup() searches udp_table->hash, and always passes 'daddr' to udp_ehashfn(). 2) When hslot->count > 10, __udp_lib_lookup() searches udp_table->hash2, but may pass 'INADDR_ANY' to udp_ehashfn() if the sockets are bound to INADDR_ANY instead of some specific addr. That means when hslot->count changes from 10 to 11, the hash calculated by udp_ehashfn() is also changed, and the udp packets belonging to a same flow will be hashed to different socket. This is easily reproduced: 1) Create 10 udp sockets and bind all of them to 0.0.0.0:40000. 2) From the same host send udp packets to 127.0.0.1:40000, record the socket index which receives the packets. 3) Create 1 more udp socket and bind it to 0.0.0.0:44096. The number 44096 is 40000 + UDP_HASH_SIZE(4096), this makes the new socket put into the same hslot as the aformentioned 10 sockets, and makes the hslot->count change from 10 to 11. 4) From the same host send udp packets to 127.0.0.1:40000, and the socket index which receives the packets will be different from the one received in step 2. This should not happen as the socket bound to 0.0.0.0:44096 should not change the behavior of the sockets bound to 0.0.0.0:40000. It's the same case for IPv6, and this patch also fixes that. Signed-off-by: Su, Xuemin <suxm@chinanetcenter.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>