tcp: fix a signed-integer-overflow bug in tcp_add_backlog()
authorLu Wei <luwei32@huawei.com>
Fri, 21 Oct 2022 04:06:22 +0000 (12:06 +0800)
committerDavid S. Miller <davem@davemloft.net>
Mon, 24 Oct 2022 12:04:25 +0000 (13:04 +0100)
commitec791d8149ff60c40ad2074af3b92a39c916a03f
treece7f42f7e4c60280ef5217ef5009c484ede4b013
parent9c1eaa27ec599fcc25ed4970c0b73c247d147a2b
tcp: fix a signed-integer-overflow bug in tcp_add_backlog()

The type of sk_rcvbuf and sk_sndbuf in struct sock is int, and
in tcp_add_backlog(), the variable limit is caculated by adding
sk_rcvbuf, sk_sndbuf and 64 * 1024, it may exceed the max value
of int and overflow. This patch reduces the limit budget by
halving the sndbuf to solve this issue since ACK packets are much
smaller than the payload.

Fixes: c9c3321257e1 ("tcp: add tcp_add_backlog()")
Signed-off-by: Lu Wei <luwei32@huawei.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/tcp_ipv4.c