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Wed, 15 Apr 2026 22:39:14 -0700 (PDT) Received: from tdc4045031631.internal.cloudapp.net ([20.63.37.123]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-50e1afc597fsm30185571cf.24.2026.04.15.22.39.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Apr 2026 22:39:13 -0700 (PDT) Message-ID: <69e07601.c80a0220.2f9024.1e0b@mx.google.com> Date: Wed, 15 Apr 2026 22:39:13 -0700 (PDT) Content-Type: text/plain; charset="us-ascii" Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Ashutosh Desai To: David Laight Cc: netdev@vger.kernel.org, linux-hams@vger.kernel.org, jreuter@yaina.de, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, stable@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 net] ax25: fix OOB read after address header strip in ax25_rcv() In-Reply-To: <20260415085921.757b48a0@pumpkin> References: <20260415063654.3831353-1-ashutoshdesai993@gmail.com> <20260415085921.757b48a0@pumpkin> On Wed, 15 Apr 2026 08:59:21 +0100, David Laight wrote: > Is it just worth linearising the skb on entry to all this code? Thanks for the feedback, David. skb_linearize() on entry is a nice idea for simplifying sanity checks overall, but it wouldn't fix this particular bug on its own - the issue is skb->len dropping to zero after skb_pull(), not non-linear data. We'd still need a length check regardless. pskb_may_pull(skb, 2) handles both in one call. That said, linearizing on entry to ax25_rcv() as a cleanup to simplify future checks sounds worthwhile - happy to send that as a separate net-next patch.