Re: [PATCH net] sctp: deny peeloff operation on asocs with threads sleeping on it

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Date: Thu, 23 Feb 2017 09:31:18 -0300

> commit 2dcab5984841 ("sctp: avoid BUG_ON on sctp_wait_for_sndbuf")
> attempted to avoid a BUG_ON call when the association being used for a
> sendmsg() is blocked waiting for more sndbuf and another thread did a
> peeloff operation on such asoc, moving it to another socket.
> 
> As Ben Hutchings noticed, then in such case it would return without
> locking back the socket and would cause two unlocks in a row.
> 
> Further analysis also revealed that it could allow a double free if the
> application managed to peeloff the asoc that is created during the
> sendmsg call, because then sctp_sendmsg() would try to free the asoc
> that was created only for that call.
> 
> This patch takes another approach. It will deny the peeloff operation
> if there is a thread sleeping on the asoc, so this situation doesn't
> exist anymore. This avoids the issues described above and also honors
> the syscalls that are already being handled (it can be multiple sendmsg
> calls).
> 
> Joint work with Xin Long.
> 
> Fixes: 2dcab5984841 ("sctp: avoid BUG_ON on sctp_wait_for_sndbuf")
> Cc: Alexander Popov <alex.popov@xxxxxxxxx>
> Cc: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
> Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
> ---
> Hi, please consider this one for -stable too. Thanks

Applied and queued up for -stable, thanks.
--
To unsubscribe from this list: send the line "unsubscribe linux-sctp" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Networking Development]     [Linux OMAP]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux