From owner-dev-commits-src-main@freebsd.org Thu Aug 26 18:15:12 2021 Return-Path: Delivered-To: dev-commits-src-main@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 3311566E8E1; Thu, 26 Aug 2021 18:15:12 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4GwWGm0m5Jz3Hdp; Thu, 26 Aug 2021 18:15:12 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 02B8314B4C; Thu, 26 Aug 2021 18:15:12 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 17QIFBgv078442; Thu, 26 Aug 2021 18:15:11 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 17QIFBTf078441; Thu, 26 Aug 2021 18:15:11 GMT (envelope-from git) Date: Thu, 26 Aug 2021 18:15:11 GMT Message-Id: <202108261815.17QIFBTf078441@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Warner Losh Subject: git: 620cf65c2bc4 - main - netinet: prevent NULL pointer dereference in in_aifaddr_ioctl() MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: imp X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 620cf65c2bc4035a07e1152da419a4e60d36ff9b Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-main@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for the main branch of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Aug 2021 18:15:12 -0000 The branch main has been updated by imp: URL: https://cgit.FreeBSD.org/src/commit/?id=620cf65c2bc4035a07e1152da419a4e60d36ff9b commit 620cf65c2bc4035a07e1152da419a4e60d36ff9b Author: Artem Khramov AuthorDate: 2021-08-24 14:26:35 +0000 Commit: Warner Losh CommitDate: 2021-08-26 18:08:03 +0000 netinet: prevent NULL pointer dereference in in_aifaddr_ioctl() It appears that maliciously crafted ifaliasreq can lead to NULL pointer dereference in in_aifaddr_ioctl(). In order to replicate that, one needs to 1. Ensure that carp(4) is not loaded 2. Issue SIOCAIFADDR call setting ifra_vhid field of the request to a negative value. A repro code would look like this. int main() { struct ifaliasreq req; struct sockaddr_in sin, mask; int fd, error; bzero(&sin, sizeof(struct sockaddr_in)); bzero(&mask, sizeof(struct sockaddr_in)); sin.sin_len = sizeof(struct sockaddr_in); sin.sin_family = AF_INET; sin.sin_addr.s_addr = inet_addr("192.168.88.2"); mask.sin_len = sizeof(struct sockaddr_in); mask.sin_family = AF_INET; mask.sin_addr.s_addr = inet_addr("255.255.255.0"); fd = socket(AF_INET, SOCK_DGRAM, 0); if (fd < 0) return (-1); memset(&req, 0, sizeof(struct ifaliasreq)); strlcpy(req.ifra_name, "lo0", sizeof(req.ifra_name)); memcpy(&req.ifra_addr, &sin, sin.sin_len); memcpy(&req.ifra_mask, &mask, mask.sin_len); req.ifra_vhid = -1; return ioctl(fd, SIOCAIFADDR, (char *)&req); } To fix, discard both positive and negative vhid values in in_aifaddr_ioctl, if carp(4) is not loaded. This prevents NULL pointer dereference and kernel panic. Reviewed by: imp@ Pull Request: https://github.com/freebsd/freebsd-src/pull/530 --- sys/netinet/in.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys/netinet/in.c b/sys/netinet/in.c index d1dd2b31b6ef..f9b46b414007 100644 --- a/sys/netinet/in.c +++ b/sys/netinet/in.c @@ -376,7 +376,7 @@ in_aifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct thread *td) (dstaddr->sin_len != sizeof(struct sockaddr_in) || dstaddr->sin_addr.s_addr == INADDR_ANY)) return (EDESTADDRREQ); - if (vhid > 0 && carp_attach_p == NULL) + if (vhid != 0 && carp_attach_p == NULL) return (EPROTONOSUPPORT); /*