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[2a01:cb05:8d23:d600:1214:6f54:f816:7b72]) by smtp.gmail.com with ESMTPSA id ld13-20020a056214418d00b0068f1237f904sm655637qvb.77.2024.02.15.05.35.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Feb 2024 05:35:59 -0800 (PST) Date: Thu, 15 Feb 2024 14:35:55 +0100 From: Guillaume Nault To: Gavrilov Ilia Cc: Michal Ostrowski , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "lvc-project@linuxtesting.org" , "syzbot+6bdfd184eac7709e5cc9@syzkaller.appspotmail.com" Subject: Re: [PATCH net] pppoe: Fix memory leak in pppoe_sendmsg() Message-ID: References: <20240214085814.3894917-1-Ilia.Gavrilov@infotecs.ru> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240214085814.3894917-1-Ilia.Gavrilov@infotecs.ru> On Wed, Feb 14, 2024 at 09:01:50AM +0000, Gavrilov Ilia wrote: > syzbot reports a memory leak in pppoe_sendmsg [1]. > > The problem is in the pppoe_recvmsg() function that handles errors > in the wrong order. For the skb_recv_datagram() function, check > the pointer to skb for NULL first, and then check the 'error' variable, > because the skb_recv_datagram() function can set 'error' > to -EAGAIN in a loop but return a correct pointer to socket buffer > after a number of attempts, though 'error' remains set to -EAGAIN. Reviewed-by: Guillaume Nault