github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-12 16:18:45 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

tcp: tcp_child_process() related UAF

Browse Source 
tcp_child_process( .. child ...) currently calls sock_put(child).

Unfortunately @child (named @nsk in callers) can be used after
this point to send a RST packet.

To fix this UAF, I remove the sock_put() from tcp_child_process()
and let the callers handle this after it is safe.

Remove @rsk variable in tcp_v4_do_rcv() and change tcp_v6_do_rcv()
so that both functions look the same.

Fixes: cfb6eeb4c8 ("[TCP]: MD5 Signature Option (RFC2385) support.")
Reported-by: Damiano Melotti <melotti@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260505153927.3435532-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Eric Dumazet 2026-05-05 15:39:27 +00:00 committed by Jakub Kicinski
parent 770b136ff9
commit c8f7244c8c
3 changed files with 15 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
net/ipv4/tcp_ipv4.c
View File

@ -1827,7 +1827,6 @@ INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
{
enum skb_drop_reason reason;
struct sock *rsk;
reason = psp_sk_rx_policy_check(sk, skb);
if (reason)
@ -1863,24 +1862,21 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
return 0;
if (nsk != sk) {
reason = tcp_child_process(sk, nsk, skb);
if (reason) {
rsk = nsk;
sock_put(nsk);
if (reason)
goto reset;
}
return 0;
}
} else
sock_rps_save_rxhash(sk, skb);
reason = tcp_rcv_state_process(sk, skb);
if (reason) {
rsk = sk;
if (reason)
goto reset;
}
return 0;
reset:
tcp_v4_send_reset(rsk, skb, sk_rst_convert_drop_reason(reason));
tcp_v4_send_reset(sk, skb, sk_rst_convert_drop_reason(reason));
discard:
sk_skb_reason_drop(sk, skb, reason);
/* Be careful here. If this function gets more complicated and
@ -2193,8 +2189,10 @@ int tcp_v4_rcv(struct sk_buff *skb)
rst_reason = sk_rst_convert_drop_reason(drop_reason);
tcp_v4_send_reset(nsk, skb, rst_reason);
sock_put(nsk);
goto discard_and_relse;
}
sock_put(nsk);
sock_put(sk);
return 0;
}

2
net/ipv4/tcp_minisocks.c
View File

@ -1012,6 +1012,6 @@ enum skb_drop_reason tcp_child_process(struct sock *parent, struct sock *child,
}
bh_unlock_sock(child);
sock_put(child);
return reason;
}

13
net/ipv6/tcp_ipv6.c
View File

@ -1617,12 +1617,13 @@ int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
if (sk->sk_state == TCP_LISTEN) {
struct sock *nsk = tcp_v6_cookie_check(sk, skb);
if (!nsk)
return 0;
if (nsk != sk) {
if (nsk) {
reason = tcp_child_process(sk, nsk, skb);
if (reason)
goto reset;
}
reason = tcp_child_process(sk, nsk, skb);
sock_put(nsk);
if (reason)
goto reset;
return 0;
}
} else
@ -1827,8 +1828,10 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
rst_reason = sk_rst_convert_drop_reason(drop_reason);
tcp_v6_send_reset(nsk, skb, rst_reason);
sock_put(nsk);
goto discard_and_relse;
}
sock_put(nsk);
sock_put(sk);
return 0;
}