Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) client-ip=23.128.96.34;
Message-ID: <18267b34-1dcf-08d5-5ba1-4f5162e6c43a@arista.com>
Date:   Thu, 21 Sep 2023 18:01:27 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.13.0
Subject: Re: [syzbot] [net?] memory leak in tcp_md5_do_add
Content-Language: en-US
To:     Eric Dumazet <edumazet@google.com>
Cc:     bpf@vger.kernel.org, davem@davemloft.net, dsahern@kernel.org,
        kuba@kernel.org, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, pabeni@redhat.com,
        syzkaller-bugs@googlegroups.com,
        syzbot <syzbot+68662811b3d5f6695bcb@syzkaller.appspotmail.com>
References: <0000000000004d83170605e16003@google.com>
 <CANn89iJwQ3TCSm+SMs=W90oThgRMLoiSAcTBJ9LH2AVsJY1NBA@mail.gmail.com>
From:   Dmitry Safonov <dima@arista.com>
In-Reply-To: <CANn89iJwQ3TCSm+SMs=W90oThgRMLoiSAcTBJ9LH2AVsJY1NBA@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

On 9/21/23 17:59, Eric Dumazet wrote:
> On Thu, Sep 21, 2023 at 6:56 PM syzbot
> <syzbot+68662811b3d5f6695bcb@syzkaller.appspotmail.com> wrote:
>>
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit:    ee3f96b16468 Merge tag 'nfsd-6.3-1' of git://git.kernel.or..
>> git tree:       upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=1312bba8c80000
>> kernel config:  https://syzkaller.appspot.com/x/.config?x=f5733ca1757172ad
>> dashboard link: https://syzkaller.appspot.com/bug?extid=68662811b3d5f6695bcb
>> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=105393a8c80000
>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1113917f480000
>>
>> Downloadable assets:
>> disk image: https://storage.googleapis.com/syzbot-assets/29e7966ab711/disk-ee3f96b1.raw.xz
>> vmlinux: https://storage.googleapis.com/syzbot-assets/ae21b8e855de/vmlinux-ee3f96b1.xz
>> kernel image: https://storage.googleapis.com/syzbot-assets/803ee0425ad6/bzImage-ee3f96b1.xz
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: syzbot+68662811b3d5f6695bcb@syzkaller.appspotmail.com
>>
>> executing program
>> BUG: memory leak
>> unreferenced object 0xffff88810a86f7a0 (size 32):
>>   comm "syz-executor325", pid 5099, jiffies 4294978342 (age 119.240s)
>>   hex dump (first 32 bytes):
>>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>>   backtrace:
>>     [<ffffffff81533d64>] kmalloc_trace+0x24/0x90 mm/slab_common.c:1061
>>     [<ffffffff840edaa0>] kmalloc include/linux/slab.h:580 [inline]
>>     [<ffffffff840edaa0>] tcp_md5sig_info_add net/ipv4/tcp_ipv4.c:1169 [inline]
>>     [<ffffffff840edaa0>] tcp_md5_do_add+0xa0/0x150 net/ipv4/tcp_ipv4.c:1240
>>     [<ffffffff84262c73>] tcp_v6_parse_md5_keys+0x253/0x4a0 net/ipv6/tcp_ipv6.c:671
>>     [<ffffffff840c720e>] do_tcp_setsockopt+0x40e/0x1360 net/ipv4/tcp.c:3720
>>     [<ffffffff840c81fb>] tcp_setsockopt+0x9b/0xa0 net/ipv4/tcp.c:3806
>>     [<ffffffff83d72a8b>] __sys_setsockopt+0x1ab/0x330 net/socket.c:2274
>>     [<ffffffff83d72c36>] __do_sys_setsockopt net/socket.c:2285 [inline]
>>     [<ffffffff83d72c36>] __se_sys_setsockopt net/socket.c:2282 [inline]
>>     [<ffffffff83d72c36>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2282
>>     [<ffffffff849ad699>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>>     [<ffffffff849ad699>] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
>>     [<ffffffff84a0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
>>
>> BUG: memory leak
>> unreferenced object 0xffff88811225ccc0 (size 192):
>>   comm "syz-executor325", pid 5099, jiffies 4294978342 (age 119.240s)
>>   hex dump (first 32 bytes):
>>     00 00 00 00 00 00 00 00 22 01 00 00 00 00 ad de  ........".......
>>     22 0a 80 00 fe 80 00 00 00 00 00 00 00 00 00 00  "...............
>>   backtrace:
>>     [<ffffffff8153444a>] __do_kmalloc_node mm/slab_common.c:966 [inline]
>>     [<ffffffff8153444a>] __kmalloc+0x4a/0x120 mm/slab_common.c:980
>>     [<ffffffff83d75c15>] kmalloc include/linux/slab.h:584 [inline]
>>     [<ffffffff83d75c15>] sock_kmalloc net/core/sock.c:2635 [inline]
>>     [<ffffffff83d75c15>] sock_kmalloc+0x65/0xa0 net/core/sock.c:2624
>>     [<ffffffff840eb9bb>] __tcp_md5_do_add+0xcb/0x300 net/ipv4/tcp_ipv4.c:1212
>>     [<ffffffff840eda67>] tcp_md5_do_add+0x67/0x150 net/ipv4/tcp_ipv4.c:1253
>>     [<ffffffff84262c73>] tcp_v6_parse_md5_keys+0x253/0x4a0 net/ipv6/tcp_ipv6.c:671
>>     [<ffffffff840c720e>] do_tcp_setsockopt+0x40e/0x1360 net/ipv4/tcp.c:3720
>>     [<ffffffff840c81fb>] tcp_setsockopt+0x9b/0xa0 net/ipv4/tcp.c:3806
>>     [<ffffffff83d72a8b>] __sys_setsockopt+0x1ab/0x330 net/socket.c:2274
>>     [<ffffffff83d72c36>] __do_sys_setsockopt net/socket.c:2285 [inline]
>>     [<ffffffff83d72c36>] __se_sys_setsockopt net/socket.c:2282 [inline]
>>     [<ffffffff83d72c36>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2282
>>     [<ffffffff849ad699>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>>     [<ffffffff849ad699>] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
>>     [<ffffffff84a0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
>>
>>
>>
>> ---
>> This report 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 issue. See:
>> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>>
>> If the bug is already fixed, let syzbot know by replying with:
>> #syz fix: exact-commit-title
>>
>> If you want syzbot to run the reproducer, reply with:
>> #syz test: git://repo/address.git branch-or-commit-hash
>> If you attach or paste a git patch, syzbot will apply it before testing.
>>
>> If you want to overwrite bug's subsystems, reply with:
>> #syz set subsystems: new-subsystem
>> (See the list of subsystem names on the web dashboard)
>>
>> If the bug is a duplicate of another bug, reply with:
>> #syz dup: exact-subject-of-another-report
>>
>> If you want to undo deduplication, reply with:
>> #syz undup
> 
> Dmitry, please take a look at this bug, we need to fix it before your
> patch series.

Sure, seems reasonable to me to fix before merging something on top.

> Thank you.

Thanks,
           Dmitry