Re: [PATCH] RDS: Fix rds-ping inducing kernel panic

[David Miller]

From: Leon Romanovsky <leon@xxxxxxxxxx>
Date: Mon, 22 Jan 2018 17:10:54 +0200

> On Mon, Jan 22, 2018 at 03:24:15AM -0800, Kees Cook wrote:
>> diff --git a/net/rds/ib_send.c b/net/rds/ib_send.c
>> index 8557a1cae041..5fbf635d17cb 100644
>> --- a/net/rds/ib_send.c
>> +++ b/net/rds/ib_send.c
>> @@ -506,7 +506,7 @@ int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
>>  	int flow_controlled = 0;
>>  	int nr_sig = 0;
>>
>> -	BUG_ON(off % RDS_FRAG_SIZE);
>> +	BUG_ON(!conn->c_loopback && off % RDS_FRAG_SIZE);
>>  	BUG_ON(hdr_off != 0 && hdr_off != sizeof(struct rds_header));
> 
> To be honest this function full of BUG_ONs and it looks fishy to have them there.
> Why don't we return EINVAL instead of crashing system?

I completely agree that these assertions should just cause an error-out
rather than trigger a BUG().