From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZo+18GWxhd0714kmc9ZBPwRGTKQfwAukOZPdi4PnIXkj//g6xasXsCiyaCL/4Def85fZ10R ARC-Seal: i=1; a=rsa-sha256; t=1526631699; cv=none; d=google.com; s=arc-20160816; b=KvUG38AqffZymrfZkiruZNGAhLZt1ya+XLMKKq9kuMP6SNgtbeGbbHirU5jBOyrqUM tkN0GDVlY2v6p0slnjPAvATKbFlsmgF3sVFAfvmx44RVMAjOQufjNXxagIOpqcxrmiBA Pz5Pil/SwqWLE0H0pHTzJbKAXToprJKabKYEgFctdCR73nq/g95HNSd0Dt8aKhXzHnyw LN3jTpAHn91A9xQiTNpzeGnsfB7P//60erdmZ+Ij43SijGdL2/HDY+nilKeOhaCSA46W Zj5Y9QorAxAn09OV0UqscVNN4FByHW8yXLMow+j/f1PY1/A808GNzvFrz+r1wA2OzFxW VbxQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature:arc-authentication-results; bh=7sDV/pp5D2+lVmas4h+Ahl71kbwK60bvhAKDRbGdMmY=; b=FKkpBnOkBSLnxRpE/NfAiYyAdFQ0AbqLKuGL8QUHeqWBHkHaTXmWyKX9AtQmiMejqV IPLMgxJJ7N78ntDrmLRLhKuLaeErXpddmWolYGtV34DTYiGeHSj7xvg7jTLkrzVwxxrK ++Z3xhlDVyIV9yKT7srncMQ3v8A05lv13pUNHvIj2YrJnNaqVjHD/F6J6w8q8oulPBdg 52Jbdrk7oBoc7/zwiQvq5uexGqUNfjUQijRa82vpwvXbePUYL93jJhm1ZgQTf7tevavZ Zu0OsFYhdtgzbgK5SKnBBaAAQXTMx1YzGQt5m34EL2kdMQPP1BSed6TA8qA5Es6mjiiA auRw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=dH5jCcA+; spf=pass (google.com: domain of srs0=xuy6=if=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=XuY6=IF=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=dH5jCcA+; spf=pass (google.com: domain of srs0=xuy6=if=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=XuY6=IF=linuxfoundation.org=gregkh@kernel.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+141d898c5f24489db4aa@syzkaller.appspotmail.com, Xin Long , Neil Horman , Marcelo Ricardo Leitner , "David S. Miller" Subject: [PATCH 4.9 16/33] sctp: remove sctp_chunk_put from fail_mark err path in sctp_ulpevent_make_rcvmsg Date: Fri, 18 May 2018 10:15:55 +0200 Message-Id: <20180518081535.758371040@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180518081535.096308218@linuxfoundation.org> References: <20180518081535.096308218@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1600789103167895925?= X-GMAIL-MSGID: =?utf-8?q?1600789360583571306?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xin Long [ Upstream commit 6910e25de2257e2c82c7a2d126e3463cd8e50810 ] In Commit 1f45f78f8e51 ("sctp: allow GSO frags to access the chunk too"), it held the chunk in sctp_ulpevent_make_rcvmsg to access it safely later in recvmsg. However, it also added sctp_chunk_put in fail_mark err path, which is only triggered before holding the chunk. syzbot reported a use-after-free crash happened on this err path, where it shouldn't call sctp_chunk_put. This patch simply removes this call. Fixes: 1f45f78f8e51 ("sctp: allow GSO frags to access the chunk too") Reported-by: syzbot+141d898c5f24489db4aa@syzkaller.appspotmail.com Signed-off-by: Xin Long Acked-by: Neil Horman Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sctp/ulpevent.c | 1 - 1 file changed, 1 deletion(-) --- a/net/sctp/ulpevent.c +++ b/net/sctp/ulpevent.c @@ -723,7 +723,6 @@ struct sctp_ulpevent *sctp_ulpevent_make return event; fail_mark: - sctp_chunk_put(chunk); kfree_skb(skb); fail: return NULL;