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tcp: fix tcp_unlink_write_queue()

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Yury reported crash with this signature :

[  554.034021] [<ffff80003ccd5a58>] 0xffff80003ccd5a58
[  554.034156] [<ffff00000888fd34>] skb_release_all+0x14/0x30
[  554.034288] [<ffff00000888fd64>] __kfree_skb+0x14/0x28
[  554.034409] [<ffff0000088ece6c>] tcp_sendmsg_locked+0x4dc/0xcc8
[  554.034541] [<ffff0000088ed68c>] tcp_sendmsg+0x34/0x58
[  554.034659] [<ffff000008919fd4>] inet_sendmsg+0x2c/0xf8
[  554.034783] [<ffff0000088842e8>] sock_sendmsg+0x18/0x30
[  554.034928] [<ffff0000088861fc>] SyS_sendto+0x84/0xf8

Problem is that skb->destructor contains garbage, and this is
because I accidentally removed tcp_skb_tsorted_anchor_cleanup()
from tcp_unlink_write_queue()

This would trigger with a write(fd, <invalid_memory>, len) attempt,
and we will add to packetdrill this capability to avoid future
regressions.

Fixes: 75c119afe1 ("tcp: implement rb-tree based retransmit queue")
Reported-by: Yury Norov <ynorov@caviumnetworks.com>
Tested-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2017-10-11 13:27:29 -07:00 committed by David S. Miller
parent df2fd38a08
commit 4a269818a7
1 changed files with 1 additions and 0 deletions
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1
include/net/tcp.h
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@ -1712,6 +1712,7 @@ static inline void tcp_insert_write_queue_before(struct sk_buff *new,
static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk)
{
tcp_skb_tsorted_anchor_cleanup(skb);
__skb_unlink(skb, &sk->sk_write_queue);
}