Re: [PATCH] sctp: Fix error handling for switch statement case in the function sctp_cmd_interprete

From: Bastien Philbert
Date: Tue Apr 05 2016 - 17:58:45 EST




On 2016-04-05 05:53 PM, Daniel Borkmann wrote:
> On 04/05/2016 11:36 PM, Bastien Philbert wrote:
>> This fixes error handling for the switch statement case
>> SCTP_CMD_SEND_PKT by making the error value of the call
>> to sctp_packet_transmit equal the variable error due to
>> this function being able to fail with a error code. In
>
> What actual issue have you observed that you fix?
>
The issue here is basically that sctp_packet_transmit
can return a error if it unsuccessfully transmit the
sk_buff as a parameter. Seems that we should signal
the user/caller(s) when a sctp packet transmission
fails here. If you would like I can resend with a better
commit message in a V2 if this explains the issue better.
Bastien
>> addition allow the call to sctp_ootb_pkt_free afterwards
>> to free up the no longer in use sctp packet even if the
>> call to the function sctp_packet_transmit fails in order
>> to avoid a memory leak here for not freeing the sctp
>
> Not sure how this relates to your code?
>
>> Signed-off-by: Bastien Philbert <bastienphilbert@xxxxxxxxx>
>> ---
>> net/sctp/sm_sideeffect.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
>> index 7fe56d0..f3a8b58 100644
>> --- a/net/sctp/sm_sideeffect.c
>> +++ b/net/sctp/sm_sideeffect.c
>> @@ -1434,7 +1434,7 @@ static int sctp_cmd_interpreter(sctp_event_t event_type,
>> case SCTP_CMD_SEND_PKT:
>> /* Send a full packet to our peer. */
>> packet = cmd->obj.packet;
>> - sctp_packet_transmit(packet, gfp);
>> + error = sctp_packet_transmit(packet, gfp);
>> sctp_ootb_pkt_free(packet);
>> break;
>>
>>
>