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=-5.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS 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 28698C433DF for ; Wed, 13 May 2020 15:25:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 42232207EA for ; Wed, 13 May 2020 15:25:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389211AbgEMPZW (ORCPT ); Wed, 13 May 2020 11:25:22 -0400 Received: from mail-il1-f200.google.com ([209.85.166.200]:33382 "EHLO mail-il1-f200.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP 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X-Received: by 2002:a92:8d49:: with SMTP id s70mr10231ild.54.1589383514058; Wed, 13 May 2020 08:25:14 -0700 (PDT) Date: Wed, 13 May 2020 08:25:14 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000c4796705a5892f6a@google.com> Subject: KMSAN: kernel-infoleak in _copy_to_iter (5) From: syzbot To: davem@davemloft.net, edumazet@google.com, glider@google.com, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, sd@queasysnail.net, syzkaller-bugs@googlegroups.com, willemb@google.com Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 14bcee29 DO-NOT-SUBMIT: kmsan: block: nullb: handle read r.. git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=1752af7c100000 kernel config: https://syzkaller.appspot.com/x/.config?x=6f048d804e1a47a0 dashboard link: https://syzkaller.appspot.com/bug?extid=50ee810676e6a089487b compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10c69b42100000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15f72658100000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+50ee810676e6a089487b@syzkaller.appspotmail.com ===================================================== BUG: KMSAN: kernel-infoleak in kmsan_copy_to_user+0x81/0x90 mm/kmsan/kmsan_hooks.c:251 CPU: 0 PID: 9041 Comm: syz-executor493 Not tainted 5.7.0-rc4-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+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118 kmsan_internal_check_memory+0x238/0x3d0 mm/kmsan/kmsan.c:423 kmsan_copy_to_user+0x81/0x90 mm/kmsan/kmsan_hooks.c:251 copyout lib/iov_iter.c:145 [inline] _copy_to_iter+0x44f/0x2770 lib/iov_iter.c:633 copy_to_iter include/linux/uio.h:138 [inline] simple_copy_to_iter net/core/datagram.c:519 [inline] __skb_datagram_iter+0x2bb/0x1220 net/core/datagram.c:425 skb_copy_datagram_iter+0x292/0x2b0 net/core/datagram.c:533 skb_copy_datagram_msg include/linux/skbuff.h:3537 [inline] packet_recvmsg+0x630/0x1c40 net/packet/af_packet.c:3378 ____sys_recvmsg+0xf58/0x1020 net/socket.c:886 ___sys_recvmsg net/socket.c:2627 [inline] do_recvmmsg+0x990/0x1e00 net/socket.c:2725 __sys_recvmmsg net/socket.c:2804 [inline] __do_sys_recvmmsg net/socket.c:2827 [inline] __se_sys_recvmmsg+0x1d1/0x350 net/socket.c:2820 __x64_sys_recvmmsg+0x62/0x80 net/socket.c:2820 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x443ca9 Code: e8 8c 07 03 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 3b 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffcf6171b28 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000443ca9 RDX: 0000000000000002 RSI: 0000000020000a80 RDI: 0000000000000003 RBP: 00007ffcf6171b30 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000142fb R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310 kmsan_memcpy_memmove_metadata+0x272/0x2e0 mm/kmsan/kmsan.c:247 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:267 __msan_memcpy+0x43/0x50 mm/kmsan/kmsan_instr.c:116 pskb_expand_head+0x38b/0x1b00 net/core/skbuff.c:1636 __skb_cow include/linux/skbuff.h:3171 [inline] skb_cow_head include/linux/skbuff.h:3205 [inline] batadv_skb_head_push+0x234/0x350 net/batman-adv/soft-interface.c:74 batadv_send_skb_packet+0x1a7/0x8c0 net/batman-adv/send.c:86 batadv_send_broadcast_skb+0x76/0x90 net/batman-adv/send.c:127 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:393 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:419 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x97e/0xd50 net/batman-adv/bat_iv_ogm.c:1710 process_one_work+0x1555/0x1f40 kernel/workqueue.c:2268 worker_thread+0xef6/0x2450 kernel/workqueue.c:2414 kthread+0x4b5/0x4f0 kernel/kthread.c:269 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:353 Uninit was created at: kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:144 kmsan_internal_alloc_meta_for_pages mm/kmsan/kmsan_shadow.c:280 [inline] kmsan_alloc_page+0xb9/0x180 mm/kmsan/kmsan_shadow.c:304 __alloc_pages_nodemask+0x56a2/0x5dc0 mm/page_alloc.c:4848 __alloc_pages include/linux/gfp.h:504 [inline] __alloc_pages_node include/linux/gfp.h:517 [inline] alloc_pages_node include/linux/gfp.h:531 [inline] __page_frag_cache_refill mm/page_alloc.c:4923 [inline] page_frag_alloc+0x3ae/0x910 mm/page_alloc.c:4953 __napi_alloc_skb+0x193/0xa60 net/core/skbuff.c:519 napi_alloc_skb include/linux/skbuff.h:2876 [inline] page_to_skb+0x1a2/0x1390 drivers/net/virtio_net.c:384 receive_mergeable drivers/net/virtio_net.c:935 [inline] receive_buf+0xed6/0x8d50 drivers/net/virtio_net.c:1045 virtnet_receive drivers/net/virtio_net.c:1335 [inline] virtnet_poll+0x64b/0x19f0 drivers/net/virtio_net.c:1440 napi_poll net/core/dev.c:6572 [inline] net_rx_action+0x786/0x1aa0 net/core/dev.c:6640 __do_softirq+0x311/0x83d kernel/softirq.c:293 Bytes 52-53 of 146 are uninitialized Memory access of size 146 starts at ffff898139239040 Data copied to user address 0000000020000980 ===================================================== --- 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#status for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches