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=-0.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 9D918ECDFB1 for ; Tue, 17 Jul 2018 13:23:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4984120C10 for ; Tue, 17 Jul 2018 13:23:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4984120C10 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by 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AOUpUlFRfU+Kcd58+TapReDpLLiI3+Y4x43CPyY5vcKFIWCJ40jTZmar 0YwRwdcBtMawzjouDYnmZ+EtDrbckAz2AM3hFyqtJ3h3MnQm X-Google-Smtp-Source: AAOMgpewwmeKK5LetLlKK0Wj5v+D9HnHk7wHXZjYxhHwb9xr9x+xJunJronE3PAZ28A+cuOtluzB2R566jaoSP2CfTxYCpG3IU+p MIME-Version: 1.0 X-Received: by 2002:a24:7acf:: with SMTP id a198-v6mr709615itc.14.1531833782557; Tue, 17 Jul 2018 06:23:02 -0700 (PDT) Date: Tue, 17 Jul 2018 06:23:02 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000076e6dc057131d87c@google.com> Subject: KMSAN: kernel-infoleak in put_cmsg From: syzbot To: davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 123906095e30 kmsan: introduce kmsan_interrupt_enter()/kmsa.. git tree: https://github.com/google/kmsan.git/master console output: https://syzkaller.appspot.com/x/log.txt?x=166dafa0400000 kernel config: https://syzkaller.appspot.com/x/.config?x=848e40757852af3e dashboard link: https://syzkaller.appspot.com/bug?extid=9adb4b567003cac781f0 compiler: clang version 7.0.0 (trunk 334104) syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=164e4ab0400000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15a41e40400000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+9adb4b567003cac781f0@syzkaller.appspotmail.com random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) ================================================================== BUG: KMSAN: kernel-infoleak in copy_to_user include/linux/uaccess.h:184 [inline] BUG: KMSAN: kernel-infoleak in put_cmsg+0x5ef/0x860 net/core/scm.c:242 CPU: 0 PID: 4501 Comm: syz-executor128 Not tainted 4.17.0+ #9 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+0x185/0x1d0 lib/dump_stack.c:113 kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1125 kmsan_internal_check_memory+0x138/0x1f0 mm/kmsan/kmsan.c:1219 kmsan_copy_to_user+0x7a/0x160 mm/kmsan/kmsan.c:1261 copy_to_user include/linux/uaccess.h:184 [inline] put_cmsg+0x5ef/0x860 net/core/scm.c:242 ip6_datagram_recv_specific_ctl+0x1cf3/0x1eb0 net/ipv6/datagram.c:719 ip6_datagram_recv_ctl+0x41c/0x450 net/ipv6/datagram.c:733 rawv6_recvmsg+0x10fb/0x1460 net/ipv6/raw.c:521 sock_common_recvmsg+0x173/0x280 net/core/sock.c:3023 sock_recvmsg_nosec net/socket.c:802 [inline] sock_recvmsg+0x1d6/0x230 net/socket.c:809 ___sys_recvmsg+0x3fe/0x810 net/socket.c:2279 __sys_recvmsg net/socket.c:2328 [inline] __do_sys_recvmsg net/socket.c:2338 [inline] __se_sys_recvmsg net/socket.c:2335 [inline] __x64_sys_recvmsg+0x325/0x460 net/socket.c:2335 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x4456b9 RSP: 002b:00007f5ce4b16da8 EFLAGS: 00000297 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 00000000004456b9 RDX: 0000000000000000 RSI: 00000000200004c0 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000297 R12: 00000000006dac20 R13: 0000000020000500 R14: 0100000000000000 R15: 0000000000000001 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:282 [inline] kmsan_save_stack mm/kmsan/kmsan.c:297 [inline] kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:689 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:464 ip6_datagram_recv_specific_ctl+0x1c3e/0x1eb0 net/ipv6/datagram.c:713 ip6_datagram_recv_ctl+0x41c/0x450 net/ipv6/datagram.c:733 rawv6_recvmsg+0x10fb/0x1460 net/ipv6/raw.c:521 sock_common_recvmsg+0x173/0x280 net/core/sock.c:3023 sock_recvmsg_nosec net/socket.c:802 [inline] sock_recvmsg+0x1d6/0x230 net/socket.c:809 ___sys_recvmsg+0x3fe/0x810 net/socket.c:2279 __sys_recvmsg net/socket.c:2328 [inline] __do_sys_recvmsg net/socket.c:2338 [inline] __se_sys_recvmsg net/socket.c:2335 [inline] __x64_sys_recvmsg+0x325/0x460 net/socket.c:2335 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:282 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:192 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:318 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:325 slab_post_alloc_hook mm/slab.h:446 [inline] slab_alloc_node mm/slub.c:2753 [inline] __kmalloc_node_track_caller+0xb35/0x11b0 mm/slub.c:4395 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:988 [inline] __ip6_append_data+0x364d/0x4fb0 net/ipv6/ip6_output.c:1434 ip6_append_data+0x40e/0x6b0 net/ipv6/ip6_output.c:1597 rawv6_sendmsg+0x2756/0x4fc0 net/ipv6/raw.c:928 inet_sendmsg+0x3fc/0x760 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg net/socket.c:639 [inline] ___sys_sendmsg+0xec8/0x1320 net/socket.c:2117 __sys_sendmsg net/socket.c:2155 [inline] __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x331/0x460 net/socket.c:2162 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Bytes 2-3 of 24 are uninitialized Memory access starts at ffff8801bde1f8a8 ================================================================== --- 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