From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail115-118.sinamail.sina.com.cn (mail115-118.sinamail.sina.com.cn [218.30.115.118]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 00B0DA923 for ; Sun, 11 Aug 2024 00:23:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=218.30.115.118 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723335817; cv=none; b=nG11OWsBg4kuUhEP5f7Rx2VFW0HCpa0DQWz/lOsoih2+AbQ+IPStXXnlsP6QsQKVbsTxxEt6tN5k8w1EzS1+bc5bovJoyhQpNrOiqcjuTb0p9ExsN0NGLHQ5Yu+WkXQR/wYcJK/FMEBIRok4YykOLQFIhK5EP9FN8RJ306yeWjk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723335817; c=relaxed/simple; bh=TIKU+MCDqRcoNgTm3cJk9HwKFQm5Q0BcDSVFrUkQicY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=aD3TCLDzsF8rCkhIoQk1uVNxrTXYynbw4GfqpW+E2oN9KQm08n+Wj160GPTUH+vV8AdwARvcOXBNl+UVTYqRuj7j2HwkRnrbyJJsMR8tv3HQbEZNuY4yfwrfo+2gLuo/AwSAIKkYSuyhbWUm87B5zQhdD/CSt9kLlFhba0BV60A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; arc=none smtp.client-ip=218.30.115.118 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([113.118.69.243]) by sina.com (10.185.250.24) with ESMTP id 66B8023D00005B42; Sun, 11 Aug 2024 08:13:52 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 46191410748375 X-SMAIL-UIID: D495B45112F04C958DB0024A92B15ADF-20240811-081352-1 From: Hillf Danton To: syzbot Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [net?] [virt?] BUG: stack guard page was hit in vsock_bpf_recvmsg Date: Sun, 11 Aug 2024 08:13:41 +0800 Message-Id: <20240811001341.2890-1-hdanton@sina.com> In-Reply-To: <0000000000005f5a6d061f43aabe@google.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Fri, 09 Aug 2024 10:42:21 -0700 > syzbot found the following issue on: > > HEAD commit: eb3ab13d997a net: ti: icssg_prueth: populate netdev of_node > git tree: net-next > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17522ec5980000 #syz test net-next eb3ab13d997a --- x/net/vmw_vsock/vsock_bpf.c +++ y/net/vmw_vsock/vsock_bpf.c @@ -77,37 +77,29 @@ static int vsock_bpf_recvmsg(struct sock size_t len, int flags, int *addr_len) { struct sk_psock *psock; - int copied; + int copied = -EAGAIN; psock = sk_psock_get(sk); if (unlikely(!psock)) - return __vsock_recvmsg(sk, msg, len, flags); + return -EAGAIN; lock_sock(sk); - if (vsock_has_data(sk, psock) && sk_psock_queue_empty(psock)) { - release_sock(sk); - sk_psock_put(sk, psock); - return __vsock_recvmsg(sk, msg, len, flags); - } + if (vsock_has_data(sk, psock) && sk_psock_queue_empty(psock)) + goto out; copied = sk_msg_recvmsg(sk, psock, msg, len, flags); while (copied == 0) { long timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); - if (!vsock_msg_wait_data(sk, psock, timeo)) { - copied = -EAGAIN; + copied = -EAGAIN; + if (!vsock_msg_wait_data(sk, psock, timeo)) + break; + if (sk_psock_queue_empty(psock)) break; - } - - if (sk_psock_queue_empty(psock)) { - release_sock(sk); - sk_psock_put(sk, psock); - return __vsock_recvmsg(sk, msg, len, flags); - } - copied = sk_msg_recvmsg(sk, psock, msg, len, flags); } +out: release_sock(sk); sk_psock_put(sk, psock); --