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Message-ID: <9d9c05f9-3c9f-a532-6829-4a36821d0f36@huawei.com>
Date:   Sun, 20 Nov 2022 14:26:46 +0800
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Subject: Re: [PATCH] xprtrdma: Fix regbuf data not freed in
 rpcrdma_req_create()
To:     Chuck Lever III <chuck.lever@oracle.com>,
        Anna Schumaker <anna@kernel.org>
CC:     Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
        Trond Myklebust <trond.myklebust@hammerspace.com>,
        Jeff Layton <jlayton@kernel.org>
References: <20221119043437.1396270-1-zhangxiaoxu5@huawei.com>
 <1A22DD8E-CA7B-4071-9DC7-7434174192A3@oracle.com>
From:   "zhangxiaoxu (A)" <zhangxiaoxu5@huawei.com>
In-Reply-To: <1A22DD8E-CA7B-4071-9DC7-7434174192A3@oracle.com>
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On 2022/11/20 0:13, Chuck Lever III wrote:
> 
> 
>> On Nov 18, 2022, at 11:34 PM, Zhang Xiaoxu <zhangxiaoxu5@huawei.com> wrote:
>>
>> If rdma receive buffer allocate failed, should call rpcrdma_regbuf_free()
>> to free the send buffer, otherwise, the buffer data will be leaked.
>>
>> Fixes: 8cec3dba76a4 ("xprtrdma: rpcrdma_regbuf alignment")
> 
> Actually Fixes: bb93a1ae2bf4 ("xprtrdma: Allocate req's regbufs
> at xprt create time") might be better. bb93a1ae2bf4 is the commit
> that incorrectly added the kfree() to rpcrdma_req_create().
> Even though 8cec3dba76a4 is what split the regbufs into two
> allocations, your fix isn't applicable to the rpcrdma_req_create()
> that's in 8cec3dba76a4.
>Thanks, I will change the fix tag and add your reviewed-by in v2.
> 
>> Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
> 
> I'm guessing the error path is getting exercised more once
> f20f18c95630 ("xprtrdma: Prevent memory allocations from driving
> a reclaim") has been applied. Good catch!
> 
> Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
> 
> 
>> ---
>> net/sunrpc/xprtrdma/verbs.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
>> index 44b87e4274b4..b098fde373ab 100644
>> --- a/net/sunrpc/xprtrdma/verbs.c
>> +++ b/net/sunrpc/xprtrdma/verbs.c
>> @@ -831,7 +831,7 @@ struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt,
>> 	return req;
>>
>> out3:
>> -	kfree(req->rl_sendbuf);
>> +	rpcrdma_regbuf_free(req->rl_sendbuf);
>> out2:
>> 	kfree(req);
>> out1:
>> -- 
>> 2.31.1
>>
> 
> --
> Chuck Lever
> 
> 
> 
>