From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 A8759C04EB8 for ; Mon, 10 Dec 2018 08:56:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5809E2082F for ; Mon, 10 Dec 2018 08:56:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="M2qGNzev" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5809E2082F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726835AbeLJI4a (ORCPT ); Mon, 10 Dec 2018 03:56:30 -0500 Received: from mail-it1-f193.google.com ([209.85.166.193]:33610 "EHLO mail-it1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726531AbeLJI43 (ORCPT ); Mon, 10 Dec 2018 03:56:29 -0500 Received: by mail-it1-f193.google.com with SMTP id m8so7423040itk.0; Mon, 10 Dec 2018 00:56:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=YZIb56R+QEb319IWfbmsRtgryH/Cf7rmiBoO94zw0Rg=; b=M2qGNzevnnAtNrPkzQStTJg1aghA5QapT2X1GI3FKivaJqjDPEoft7ink3ddBMFyWO EbGhGxGKSVih4iYVUVwR/YB8Jnc2XRFyneNtpwE1IH+D104hZsLc3L5YvViQJezr87iA 7zgXyq8VAWq5WOgK0d7MfmnoNuMrjYM9BYavlvih0ZODx/Nx/HMQF2J30nO7wbNzXvYC hdgZQGLXS9eDYriXjzTFCJY8qKqDx9ffDEWWTwQrfrR/mb4BVAYxwkoLY0BOL+f9hRFC /dk54DBzPR/7DV5Pegpkrg1FYwoJsxDHqOvuKR6hVJstr1VrVRQEFe1vgA+qItH4c0kj Bjmg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=YZIb56R+QEb319IWfbmsRtgryH/Cf7rmiBoO94zw0Rg=; b=BS5yAuaRcH9OsGi4tzPNRzvC7uYAs/OvAxJR8X087LYIBCXwXJzxWLxXZd4V4tUCah 0xyx7vjDMiPbuCCoHgTPagKxyVCYONC1bL7VUrjCLjBgprdzBTftuuKuYahulOQDCgp9 /QWzvC8kKqirUGuQMFuK7uTfEF9dK5vzvmElNbUWItcB5n/4aVi5EHN+OaPH1IVGGUzd +HiniF/XPwymKVXdB2CPqbN5o+5Sk5VWqHI1IVqsj/GLSAu4f0E1y0DGQAnQgEmnEJ2F LnfCMsSc1gBset6S7DwGSjZ8XsdSsqnqjdxYlew3WEJJbph7dvuzo0g9nPeaaPvpaYGE 3Tmg== X-Gm-Message-State: AA+aEWYiYdjIy+ImD2YSBzfUO1QbsCWHOgoVHzJ4TOIuRoJymjASlxkm dmgy+jPHAuDj9IDpFazPnDK2QQ3tSiLi7S351EU= X-Google-Smtp-Source: AFSGD/UQB9TByUGNaRYkNYcGpJIrRfq7G+I0GDcj4uef51UlPuF7/1jrzrh54xlBNV6lWyo1NcMPchkNGR5wZXEoZuk= X-Received: by 2002:a05:660c:58a:: with SMTP id g10mr9484104itk.167.1544432187069; Mon, 10 Dec 2018 00:56:27 -0800 (PST) MIME-Version: 1.0 References: <000000000000311344057c4b6cc3@google.com> <20181206110634.GA9056@localhost.localdomain> In-Reply-To: <20181206110634.GA9056@localhost.localdomain> From: Xin Long Date: Mon, 10 Dec 2018 17:56:14 +0900 Message-ID: Subject: Re: KMSAN: kernel-infoleak in sctp_getsockopt To: Marcelo Ricardo Leitner Cc: Alexander Potapenko , syzbot+ad5d327e6936a2e284be@syzkaller.appspotmail.com, davem , LKML , linux-sctp@vger.kernel.org, network dev , Neil Horman , syzkaller-bugs , Vlad Yasevich Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 6, 2018 at 8:08 PM Marcelo Ricardo Leitner wrote: > > On Thu, Dec 06, 2018 at 11:36:08AM +0100, Alexander Potapenko wrote: > > On Wed, Dec 5, 2018 at 8:31 PM syzbot > > wrote: > > > > > > Hello, > > > > > > syzbot found the following crash on: > > > > > > HEAD commit: fffec98ae2a6 net: proper support for CONFIG_GENERIC_C= SUM o.. > > > git tree: https://github.com/google/kmsan.git/master > > > console output: https://syzkaller.appspot.com/x/log.txt?x=3D12e84a474= 00000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=3D56b48b46d= afe4516 > > > dashboard link: https://syzkaller.appspot.com/bug?extid=3Dad5d327e693= 6a2e284be > > > compiler: clang version 8.0.0 (trunk 343298) > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=3D103cd22= 5400000 > > > > > > IMPORTANT: if you fix the bug, please add the following tag to the co= mmit: > > > Reported-by: syzbot+ad5d327e6936a2e284be@syzkaller.appspotmail.com > > > > > > 8021q: adding VLAN 0 to HW filter on device team0 > > > 8021q: adding VLAN 0 to HW filter on device team0 > > > 8021q: adding VLAN 0 to HW filter on device team0 > > > 8021q: adding VLAN 0 to HW filter on device team0 > > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > > > BUG: KMSAN: kernel-infoleak in _copy_to_user+0x19a/0x230 lib/usercopy= .c:33 > > > CPU: 1 PID: 8164 Comm: syz-executor2 Not tainted 4.20.0-rc3+ #95 > > > Hardware name: Google Google Compute Engine/Google Compute Engine, BI= OS > > > Google 01/01/2011 > > > Call Trace: > > > __dump_stack lib/dump_stack.c:77 [inline] > > > dump_stack+0x32d/0x480 lib/dump_stack.c:113 > > > kmsan_report+0x12c/0x290 mm/kmsan/kmsan.c:683 > > > kmsan_internal_check_memory+0x32a/0xa50 mm/kmsan/kmsan.c:743 > > > kmsan_copy_to_user+0x78/0xd0 mm/kmsan/kmsan_hooks.c:634 > > > _copy_to_user+0x19a/0x230 lib/usercopy.c:33 > > > copy_to_user include/linux/uaccess.h:183 [inline] > > > sctp_getsockopt_local_addrs net/sctp/socket.c:5998 [inline] > > > sctp_getsockopt+0x15248/0x186f0 net/sctp/socket.c:7477 > > > sock_common_getsockopt+0x13f/0x180 net/core/sock.c:2937 > > > __sys_getsockopt+0x489/0x550 net/socket.c:1939 > > > __do_sys_getsockopt net/socket.c:1950 [inline] > > > __se_sys_getsockopt+0xe1/0x100 net/socket.c:1947 > > > __x64_sys_getsockopt+0x62/0x80 net/socket.c:1947 > > > do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291 > > > entry_SYSCALL_64_after_hwframe+0x63/0xe7 > > > RIP: 0033:0x457569 > > > Code: fd b3 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 f= 0 ff > > > ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > > > RSP: 002b:00007f4991886c78 EFLAGS: 00000246 ORIG_RAX: 000000000000003= 7 > > > RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457569 > > > RDX: 000000000000006d RSI: 0000000000000084 RDI: 0000000000000003 > > > RBP: 000000000072bf00 R08: 0000000020000140 R09: 0000000000000000 > > > R10: 0000000020001100 R11: 0000000000000246 R12: 00007f49918876d4 > > > R13: 00000000004c7d88 R14: 00000000004ce348 R15: 00000000ffffffff > > > > > > Uninit was stored to memory at: > > > kmsan_save_stack_with_flags mm/kmsan/kmsan.c:246 [inline] > > > kmsan_save_stack mm/kmsan/kmsan.c:261 [inline] > > > kmsan_internal_chain_origin+0x13d/0x240 mm/kmsan/kmsan.c:469 > > > kmsan_memcpy_memmove_metadata+0x1a9/0xf70 mm/kmsan/kmsan.c:344 > > > kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:362 > > > __msan_memcpy+0x61/0x70 mm/kmsan/kmsan_instr.c:162 > > > sctp_copy_laddrs net/sctp/socket.c:5901 [inline] > > > sctp_getsockopt_local_addrs net/sctp/socket.c:5967 [inline] > > > sctp_getsockopt+0x14f41/0x186f0 net/sctp/socket.c:7477 > > > sock_common_getsockopt+0x13f/0x180 net/core/sock.c:2937 > > > __sys_getsockopt+0x489/0x550 net/socket.c:1939 > > > __do_sys_getsockopt net/socket.c:1950 [inline] > > > __se_sys_getsockopt+0xe1/0x100 net/socket.c:1947 > > > __x64_sys_getsockopt+0x62/0x80 net/socket.c:1947 > > > do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291 > > > entry_SYSCALL_64_after_hwframe+0x63/0xe7 > > > > > > Uninit was stored to memory at: > > > kmsan_save_stack_with_flags mm/kmsan/kmsan.c:246 [inline] > > > kmsan_save_stack mm/kmsan/kmsan.c:261 [inline] > > > kmsan_internal_chain_origin+0x13d/0x240 mm/kmsan/kmsan.c:469 > > > kmsan_memcpy_memmove_metadata+0x1a9/0xf70 mm/kmsan/kmsan.c:344 > > > kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:362 > > > __msan_memcpy+0x61/0x70 mm/kmsan/kmsan_instr.c:162 > > > sctp_copy_laddrs net/sctp/socket.c:5890 [inline] > > > sctp_getsockopt_local_addrs net/sctp/socket.c:5967 [inline] > > > sctp_getsockopt+0x14de8/0x186f0 net/sctp/socket.c:7477 > > > sock_common_getsockopt+0x13f/0x180 net/core/sock.c:2937 > > > __sys_getsockopt+0x489/0x550 net/socket.c:1939 > > > __do_sys_getsockopt net/socket.c:1950 [inline] > > > __se_sys_getsockopt+0xe1/0x100 net/socket.c:1947 > > > __x64_sys_getsockopt+0x62/0x80 net/socket.c:1947 > > > do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291 > > > entry_SYSCALL_64_after_hwframe+0x63/0xe7 > > > > > > Uninit was created at: > > > kmsan_save_stack_with_flags mm/kmsan/kmsan.c:246 [inline] > > > kmsan_internal_poison_shadow+0x6d/0x130 mm/kmsan/kmsan.c:170 > > > kmsan_kmalloc+0xa1/0x100 mm/kmsan/kmsan_hooks.c:186 > > > __kmalloc+0x14c/0x4d0 mm/slub.c:3825 > > > kmalloc include/linux/slab.h:551 [inline] > > > sctp_inet6addr_event+0x60e/0xbd0 net/sctp/ipv6.c:100 > > > notifier_call_chain kernel/notifier.c:93 [inline] > > > __atomic_notifier_call_chain kernel/notifier.c:183 [inline] > > > atomic_notifier_call_chain+0x13d/0x240 kernel/notifier.c:193 > > > inet6addr_notifier_call_chain+0x76/0x90 net/ipv6/addrconf_core.c:10= 7 > > > ipv6_add_addr+0x2597/0x2890 net/ipv6/addrconf.c:1115 > > > inet6_addr_add+0xc86/0x1c10 net/ipv6/addrconf.c:2912 > > > inet6_rtm_newaddr+0x167e/0x3d20 net/ipv6/addrconf.c:4750 > > > rtnetlink_rcv_msg+0x1148/0x1540 net/core/rtnetlink.c:4947 > > > netlink_rcv_skb+0x394/0x640 net/netlink/af_netlink.c:2477 > > > rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4965 > > > netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] > > > netlink_unicast+0x1699/0x1740 net/netlink/af_netlink.c:1336 > > > netlink_sendmsg+0x13c7/0x1440 net/netlink/af_netlink.c:1917 > > > sock_sendmsg_nosec net/socket.c:621 [inline] > > > sock_sendmsg net/socket.c:631 [inline] > > > ___sys_sendmsg+0xe3b/0x1240 net/socket.c:2116 > > > __sys_sendmsg net/socket.c:2154 [inline] > > > __do_sys_sendmsg net/socket.c:2163 [inline] > > > __se_sys_sendmsg+0x305/0x460 net/socket.c:2161 > > > __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161 > > > do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291 > > > entry_SYSCALL_64_after_hwframe+0x63/0xe7 > > > > > > Bytes 32-35 of 2100 are uninitialized > > > Memory access of size 2100 starts at ffff888185d8b000 > > > Data copied to user address 0000000020001108 > > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > > When a network device goes up and sctp_inetaddr_event() is called, it > > allocates a partially initialized struct sctp_sockaddr_entry to hold > > the newly created address. > > The attached reproducer can be then used to read up to 8 uninit bytes > > for each of the local addresses. > > I guess the devices aren't created so often that this can pose any > > security risk, but we probably still need to allocate this structure > > with __GFP_ZERO. > > Agree. Thanks Alexander. > Looks like this is the last/only place left with this issue. This field is not really used by sctp, I will just set it to 0. diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c index fc6c5e4bffa5..7f0539db5604 100644 --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -101,6 +101,7 @@ static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev, if (addr) { addr->a.v6.sin6_family =3D AF_INET6; addr->a.v6.sin6_port =3D 0; + addr->a.v6.sin6_flowinfo =3D 0; addr->a.v6.sin6_addr =3D ifa->addr; addr->a.v6.sin6_scope_id =3D ifa->idev->dev->ifinde= x; addr->valid =3D 1; > > > > > > > --- > > > This bug is generated by a bot. It may contain errors. > > > See https://goo.gl/tpsmEJ for more information about syzbot. > > > syzbot engineers can be reached at syzkaller@googlegroups.com. > > > > > > syzbot will keep track of this bug report. See: > > > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > > > syzbot. > > > syzbot can test patches for this bug, for details see: > > > https://goo.gl/tpsmEJ#testing-patches > > > > > > -- > > > You received this message because you are subscribed to the Google Gr= oups "syzkaller-bugs" group. > > > To unsubscribe from this group and stop receiving emails from it, sen= d an email to syzkaller-bugs+unsubscribe@googlegroups.com. > > > To view this discussion on the web visit https://groups.google.com/d/= msgid/syzkaller-bugs/000000000000311344057c4b6cc3%40google.com. > > > For more options, visit https://groups.google.com/d/optout. > > > > > > > > -- > > Alexander Potapenko > > Software Engineer > > > > Google Germany GmbH > > Erika-Mann-Stra=C3=9Fe, 33 > > 80636 M=C3=BCnchen > > > > Gesch=C3=A4ftsf=C3=BChrer: Paul Manicle, Halimah DeLaine Prado > > Registergericht und -nummer: Hamburg, HRB 86891 > > Sitz der Gesellschaft: Hamburg > > > #ifndef DUMP_BUF_H > > #define DUMP_BUF_H > > > > #ifndef DUMP_MIN_STRLEN > > #define DUMP_MIN_STRLEN 1 > > #endif > > > > #ifndef DUMP_PARALLEL > > #define DUMP_PARALLEL 0 > > #endif > > > > #ifndef DUMP_PRINT_BUF_ADDR > > #define DUMP_PRINT_BUF_ADDR 0 > > #endif > > > > #ifndef DUMP_PRINT_HEX > > #define DUMP_PRINT_HEX 0 > > #endif > > > > #ifndef DUMP_PRINT_STRING > > #define DUMP_PRINT_STRING 0 > > #endif > > > > #if DUMP_PARALLEL > > pthread_mutex_t out_mutex =3D PTHREAD_MUTEX_INITIALIZER; > > #endif > > > > void dump_buf(unsigned char *buf, int len) { > > int i, nz =3D 0; > > for (i =3D 0; i < len; i++) { > > if (buf[i]) { > > nz =3D 1; > > break; > > } > > } > > if (!nz) { > > // The buffer is empty. > > return; > > } else { > > #if DUMP_PARALLEL > > pthread_mutex_lock(&out_mutex); > > #endif > > #if DUMP_PRINT_BUF_ADDR > > fprintf(stderr, "nonempty buffer at %p\n", buf); > > #endif > > #if DUMP_PRINT_HEX > > for (i=3D0; i < len; i++) { > > if (buf[i]) { > > fprintf(stderr, "buf[%d]: %x (%p)\n", i, buf[i], *(void**)&buf[= i]); > > } > > } > > #endif // DUMP_PRINT_HEX > > #if DUMP_PARALLEL > > pthread_mutex_unlock(&out_mutex); > > #endif > > } > > #if DUMP_PARALLEL > > pthread_mutex_lock(&out_mutex); > > #endif > > #if DUMP_PRINT_STRING > > for (i =3D 0; i < len; i++) { > > if (buf[i]) { > > int str_len =3D strlen(&buf[i]); > > // Short string pieces are too boring. > > if (str_len >=3D DUMP_MIN_STRLEN) { > > unsigned char *c; > > for (c =3D &buf[i]; c < &buf[i + str_len]; c++) { > > if ((*c > 127) || ((*c < 32) && (*c !=3D 10) && (*c !=3D 13))= ) { > > *c =3D ' '; > > continue; > > } > > } > > // Dump the buffer. > > fprintf(stderr, "%s\n", &buf[i]); > > } > > i +=3D str_len; > > } > > } > > #endif // DUMP_PRINT_STRING > > #if DUMP_PARALLEL > > pthread_mutex_unlock(&out_mutex); > > #endif > > } > > > > #endif > > > #include > > #include > > #include /* See NOTES */ > > #include > > #include > > > > #define DUMP_PARALLEL 1 > > #define DUMP_PRINT_BUF_ADDR 1 > > #define DUMP_PRINT_STRING 1 > > #define DUMP_PRINT_HEX 1 > > #include "dump_buf.h" > > > > void *setsockopt_fn(void *arg) { > > int sock =3D (int)arg; > > struct sockaddr addr; > > memset(&addr, 0, sizeof(addr)); > > addr.sa_family =3D 2; > > addr.sa_data[2] =3D 0xac; > > addr.sa_data[3] =3D 0x14; > > addr.sa_data[4] =3D 0x14; > > setsockopt(sock, 0x84, 0x6e, &addr, 0x10); > > } > > > > #define BUFLEN (0x2c2) > > void *getsockopt_fn(void *arg) { > > int sock =3D (int)arg; > > char buf[BUFLEN]; > > memset(buf, 0, BUFLEN); > > int socklen =3D BUFLEN; > > getsockopt(sock, 0x84, /*SCTP_GET_LOCAL_ADDRS*/0x6d, buf, &socklen); > > dump_buf(&(buf[8]), 32); > > } > > > > void do_work(int sock) { > > pthread_t t1, t2; > > for (int i =3D 0; i < 10; i++) { > > pthread_create(&t1, NULL, getsockopt_fn, (void*)sock); > > pthread_create(&t2, NULL, setsockopt_fn, (void*)sock); > > usleep(100); > > } > > } > > > > int main(int argc, char *argv[]) { > > int res; > > int pid =3D fork(); > > if (pid =3D=3D 0) { > > int sock =3D socket(0x2, 0x1, 0x84); > > do_work(sock); > > } > > sleep(10); > > return 0; > > } >