linux-kernel - Re: BUG: unable to handle kernel NULL pointer dereference in inet

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <3f2984d7-f854-2457-8bbe-7e8b1a377d66@gmail.com>
Date:   Tue, 25 Feb 2020 00:15:26 -0800
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     syzbot <syzbot+1938db17e275e85dc328@...kaller.appspotmail.com>,
        andriin@...com, ast@...nel.org, bpf@...r.kernel.org,
        daniel@...earbox.net, davem@...emloft.net, kafai@...com,
        kuba@...nel.org, kuznet@....inr.ac.ru,
        linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
        songliubraving@...com, syzkaller-bugs@...glegroups.com, yhs@...com
Subject: Re: BUG: unable to handle kernel NULL pointer dereference in
 inet_release



On 2/25/20 12:08 AM, syzbot wrote:
> Hello,
> 
> syzbot found the following crash on:
> 
> HEAD commit:    54dedb5b Merge tag 'for-linus-5.6-rc3-tag' of git://git.ke..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=168f7de9e00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=3e57a6b450fb9883
> dashboard link: https://syzkaller.appspot.com/bug?extid=1938db17e275e85dc328
> compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1681fe09e00000
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+1938db17e275e85dc328@...kaller.appspotmail.com
> 
> BUG: kernel NULL pointer dereference, address: 0000000000000000
> #PF: supervisor instruction fetch in kernel mode
> #PF: error_code(0x0010) - not-present page
> PGD a0113067 P4D a0113067 PUD a8771067 PMD 0 
> Oops: 0010 [#1] PREEMPT SMP KASAN
> CPU: 0 PID: 10686 Comm: syz-executor.0 Not tainted 5.6.0-rc2-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> RIP: 0010:0x0
> Code: Bad RIP value.
> RSP: 0018:ffffc9000281fce0 EFLAGS: 00010246
> RAX: 1ffffffff15f48ac RBX: ffffffff8afa4560 RCX: dffffc0000000000
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a69a8f40
> RBP: ffffc9000281fd10 R08: ffffffff86ed9b0c R09: ffffed1014d351f5
> R10: ffffed1014d351f5 R11: 0000000000000000 R12: ffff8880920d3098
> R13: 1ffff1101241a613 R14: ffff8880a69a8f40 R15: 0000000000000000
> FS:  00007f2ae75db700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: ffffffffffffffd6 CR3: 00000000a3b85000 CR4: 00000000001406f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  inet_release+0x165/0x1c0 net/ipv4/af_inet.c:427
>  __sock_release net/socket.c:605 [inline]
>  sock_close+0xe1/0x260 net/socket.c:1283
>  __fput+0x2e4/0x740 fs/file_table.c:280
>  ____fput+0x15/0x20 fs/file_table.c:313
>  task_work_run+0x176/0x1b0 kernel/task_work.c:113
>  tracehook_notify_resume include/linux/tracehook.h:188 [inline]
>  exit_to_usermode_loop arch/x86/entry/common.c:164 [inline]
>  prepare_exit_to_usermode+0x480/0x5b0 arch/x86/entry/common.c:195
>  syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:278
>  do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:304
>  entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x45c429
> 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:00007f2ae75dac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
> RAX: 0000000000000000 RBX: 00007f2ae75db6d4 RCX: 000000000045c429
> RDX: 0000000000000001 RSI: 000000000000011a RDI: 0000000000000004
> RBP: 000000000076bf20 R08: 0000000000000038 R09: 0000000000000000
> R10: 0000000020000180 R11: 0000000000000246 R12: 00000000ffffffff
> R13: 0000000000000a9d R14: 00000000004ccfb4 R15: 000000000076bf2c
> Modules linked in:
> CR2: 0000000000000000
> ---[ end trace 82567b5207e87bae ]---
> RIP: 0010:0x0
> Code: Bad RIP value.
> RSP: 0018:ffffc9000281fce0 EFLAGS: 00010246
> RAX: 1ffffffff15f48ac RBX: ffffffff8afa4560 RCX: dffffc0000000000
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a69a8f40
> RBP: ffffc9000281fd10 R08: ffffffff86ed9b0c R09: ffffed1014d351f5
> R10: ffffed1014d351f5 R11: 0000000000000000 R12: ffff8880920d3098
> R13: 1ffff1101241a613 R14: ffff8880a69a8f40 R15: 0000000000000000
> FS:  00007f2ae75db700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: ffffffffffffffd6 CR3: 00000000a3b85000 CR4: 00000000001406f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> 
> 
> ---
> 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@...glegroups.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
> 

Note to ULP maintainers

Probably the code for IPV6_ADDRFORM  needs some care if a TCP socket got ULP enabled ?