From: Jonathan Cameron Subject: Re: [PATCH v3] crypto: AF_ALG - remove locking in async callback Date: Fri, 24 Nov 2017 17:37:17 +0000 Message-ID: <20171124173717.00000d3f@huawei.com> References: <1966139.WIlnTlQG5u@positron.chronox.de> <20171124073739.GB15597@gondor.apana.org.au> <12422115.UWn9hbrTTi@tauon.chronox.de> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Cc: Herbert Xu , Tudor Ambarus , Cyrille Pitchen , linux-crypto@vger.kernel.org, Romain Izard , linux-arm-kernel To: Stephan Mueller Return-path: In-Reply-To: <12422115.UWn9hbrTTi@tauon.chronox.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org List-Id: linux-crypto.vger.kernel.org On Fri, 24 Nov 2017 17:04:19 +0100 Stephan Mueller wrote: > Am Freitag, 24. November 2017, 08:37:39 CET schrieb Herbert Xu: > = > Hi Herbert, > = > > On Fri, Nov 10, 2017 at 01:20:55PM +0100, Stephan M=FCller wrote: = > > > The code paths protected by the socket-lock do not use or modify the > > > socket in a non-atomic fashion. The actions pertaining the socket do = not > > > even need to be handled as an atomic operation. Thus, the socket-lock > > > can be safely ignored. > > > = > > > This fixes a bug regarding scheduling in atomic as the callback funct= ion > > > may be invoked in interrupt context. > > > = > > > In addition, the sock_hold is moved before the AIO encrypt/decrypt > > > operation to ensure that the socket is always present. This avoids a > > > tiny race window where the socket is unprotected and yet used by the = AIO > > > operation. > > > = > > > Finally, the release of resources for a crypto operation is moved int= o a > > > common function of af_alg_free_resources. > > > = > > > Fixes: e870456d8e7c8 ("crypto: algif_skcipher - overhaul memory > > > management") Fixes: d887c52d6ae43 ("crypto: algif_aead - overhaul mem= ory > > > management") Reported-by: Romain Izard > > > Signed-off-by: Stephan Mueller = > > = > > Patch applied. Thanks. = > = > Thanks a lot. > = > Would it make sense to feed it to stable? > = > Ciao > Stephan My view would be definitely. Ran into this precise issue whilst testing a new driver 4.14 today... Jonathan