Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.13 11/44] sctp: add the missing sock_owned_by_user check in sctp_icmp_redirect | Date | Thu, 16 Nov 2017 18:42:35 +0100 |
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4.13-stable review patch. If anyone has any objections, please let me know.
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From: Xin Long <lucien.xin@gmail.com>
[ Upstream commit 1cc276cec9ec574d41cf47dfc0f51406b6f26ab4 ]
Now sctp processes icmp redirect packet in sctp_icmp_redirect where it calls sctp_transport_dst_check in which tp->dst can be released.
The problem is before calling sctp_transport_dst_check, it doesn't check sock_owned_by_user, which means tp->dst could be freed while a process is accessing it with owning the socket.
An use-after-free issue could be triggered by this.
This patch is to fix it by checking sock_owned_by_user before calling sctp_transport_dst_check in sctp_icmp_redirect, so that it would not release tp->dst if users still hold sock lock.
Besides, the same issue fixed in commit 45caeaa5ac0b ("dccp/tcp: fix routing redirect race") on sctp also needs this check.
Fixes: 55be7a9c6074 ("ipv4: Add redirect support to all protocol icmp error handlers") Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/sctp/input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/sctp/input.c +++ b/net/sctp/input.c @@ -421,7 +421,7 @@ void sctp_icmp_redirect(struct sock *sk, { struct dst_entry *dst; - if (!t) + if (sock_owned_by_user(sk) || !t) return; dst = sctp_transport_dst_check(t); if (dst)
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