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Subject: Re: [PATCH] Bluetooth: cmtp: fix possible panic when
 cmtp_init_sockets() fails
To:     Marcel Holtmann <marcel@holtmann.org>
CC:     Karsten Keil <isdn@linux-pingi.de>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Thadeu Lima de Souza Cascardo <cascardo@canonical.com>,
        "open list:NETWORKING [GENERAL]" <netdev@vger.kernel.org>,
        <linux-bluetooth@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20211022034417.766659-1-wanghai38@huawei.com>
 <9D8B1F5B-8EFE-40CB-BC85-F6EC3483CC61@holtmann.org>
From:   "wanghai (M)" <wanghai38@huawei.com>
Message-ID: <ca60862b-594f-3b79-5683-1e3d78811f42@huawei.com>
Date:   Fri, 22 Oct 2021 16:43:59 +0800
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?? 2021/10/22 12:48, Marcel Holtmann д??:
> Hi Wang,
>
>> I got a kernel BUG report when doing fault injection test:
>>
>> ------------[ cut here ]------------
>> kernel BUG at lib/list_debug.c:45!
>> ...
>> RIP: 0010:__list_del_entry_valid.cold+0x12/0x4d
>> ...
>> Call Trace:
>> proto_unregister+0x83/0x220
>> cmtp_cleanup_sockets+0x37/0x40 [cmtp]
>> cmtp_exit+0xe/0x1f [cmtp]
>> do_syscall_64+0x35/0xb0
>> entry_SYSCALL_64_after_hwframe+0x44/0xae
>>
>> If cmtp_init_sockets() in cmtp_init() fails, cmtp_init() still returns
>> success. This will cause a kernel bug when accessing uncreated ctmp
>> related data when the module exits.
>>
>> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
>> Reported-by: Hulk Robot <hulkci@huawei.com>
>> Signed-off-by: Wang Hai <wanghai38@huawei.com>
>> ---
>> net/bluetooth/cmtp/core.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/bluetooth/cmtp/core.c b/net/bluetooth/cmtp/core.c
>> index 0a2d78e811cf..ccf48f50afdf 100644
>> --- a/net/bluetooth/cmtp/core.c
>> +++ b/net/bluetooth/cmtp/core.c
>> @@ -499,11 +499,13 @@ int cmtp_get_conninfo(struct cmtp_conninfo *ci)
>>
>> static int __init cmtp_init(void)
>> {
>> +	int err;
>> +
>> 	BT_INFO("CMTP (CAPI Emulation) ver %s", VERSION);
>>
>> -	cmtp_init_sockets();
>> +	err = cmtp_init_sockets();
>>
>> -	return 0;
>> +	return err;
>> }
> just do return cmtp_init_sockets();
>
> Regards
>
> Marcel
Ok, I will send v2
> .
>
-- 
Wang Hai