From patchwork Tue Apr 7 22:29:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 221374 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B40EC2BB54 for ; Tue, 7 Apr 2020 22:30:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 53E4F207FF for ; Tue, 7 Apr 2020 22:30:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726767AbgDGWaE (ORCPT ); Tue, 7 Apr 2020 18:30:04 -0400 Received: from correo.us.es ([193.147.175.20]:53156 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726571AbgDGW3q (ORCPT ); Tue, 7 Apr 2020 18:29:46 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 77D0BF2DE3 for ; Wed, 8 Apr 2020 00:29:44 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 65F3DDA3C2 for ; Wed, 8 Apr 2020 00:29:44 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id 5B926DA7B2; Wed, 8 Apr 2020 00:29:44 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 5D88EDA788; Wed, 8 Apr 2020 00:29:42 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Wed, 08 Apr 2020 00:29:42 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from salvia.here (unknown [90.77.255.23]) (Authenticated sender: pneira@us.es) by entrada.int (Postfix) with ESMTPA id 39D014251480; Wed, 8 Apr 2020 00:29:42 +0200 (CEST) X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org Subject: [PATCH 4/7] netfilter: nf_tables: do not leave dangling pointer in nf_tables_set_alloc_name Date: Wed, 8 Apr 2020 00:29:33 +0200 Message-Id: <20200407222936.206295-5-pablo@netfilter.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20200407222936.206295-1-pablo@netfilter.org> References: <20200407222936.206295-1-pablo@netfilter.org> X-Virus-Scanned: ClamAV using ClamSMTP Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Eric Dumazet If nf_tables_set_alloc_name() frees set->name, we better clear set->name to avoid a future use-after-free or invalid-free. BUG: KASAN: double-free or invalid-free in nf_tables_newset+0x1ed6/0x2560 net/netfilter/nf_tables_api.c:4148 CPU: 0 PID: 28233 Comm: syz-executor.0 Not tainted 5.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:374 kasan_report_invalid_free+0x61/0xa0 mm/kasan/report.c:468 __kasan_slab_free+0x129/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 nf_tables_newset+0x1ed6/0x2560 net/netfilter/nf_tables_api.c:4148 nfnetlink_rcv_batch+0x83a/0x1610 net/netfilter/nfnetlink.c:433 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:543 [inline] nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:561 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6b9/0x7d0 net/socket.c:2345 ___sys_sendmsg+0x100/0x170 net/socket.c:2399 __sys_sendmsg+0xec/0x1b0 net/socket.c:2432 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c849 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe5ca21dc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fe5ca21e6d4 RCX: 000000000045c849 RDX: 0000000000000000 RSI: 0000000020000c40 RDI: 0000000000000003 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000095b R14: 00000000004cc0e9 R15: 000000000076bf0c Allocated by task 28233: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:488 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc_track_caller+0x159/0x790 mm/slab.c:3671 kvasprintf+0xb5/0x150 lib/kasprintf.c:25 kasprintf+0xbb/0xf0 lib/kasprintf.c:59 nf_tables_set_alloc_name net/netfilter/nf_tables_api.c:3536 [inline] nf_tables_newset+0x1543/0x2560 net/netfilter/nf_tables_api.c:4088 nfnetlink_rcv_batch+0x83a/0x1610 net/netfilter/nfnetlink.c:433 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:543 [inline] nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:561 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6b9/0x7d0 net/socket.c:2345 ___sys_sendmsg+0x100/0x170 net/socket.c:2399 __sys_sendmsg+0xec/0x1b0 net/socket.c:2432 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 28233: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:476 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 nf_tables_set_alloc_name net/netfilter/nf_tables_api.c:3544 [inline] nf_tables_newset+0x1f73/0x2560 net/netfilter/nf_tables_api.c:4088 nfnetlink_rcv_batch+0x83a/0x1610 net/netfilter/nfnetlink.c:433 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:543 [inline] nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:561 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6b9/0x7d0 net/socket.c:2345 ___sys_sendmsg+0x100/0x170 net/socket.c:2399 __sys_sendmsg+0xec/0x1b0 net/socket.c:2432 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a6032d00 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of 32-byte region [ffff8880a6032d00, ffff8880a6032d20) The buggy address belongs to the page: page:ffffea0002980c80 refcount:1 mapcount:0 mapping:ffff8880aa0001c0 index:0xffff8880a6032fc1 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002a3be88 ffffea00029b1908 ffff8880aa0001c0 raw: ffff8880a6032fc1 ffff8880a6032000 000000010000003e 0000000000000000 page dumped because: kasan: bad access detected Fixes: 65038428b2c6 ("netfilter: nf_tables: allow to specify stateful expression in set definition") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index d0ab5ffa1e2c..f91e96d8de05 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3542,6 +3542,7 @@ static int nf_tables_set_alloc_name(struct nft_ctx *ctx, struct nft_set *set, continue; if (!strcmp(set->name, i->name)) { kfree(set->name); + set->name = NULL; return -ENFILE; } }