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Date:   Sat, 27 May 2023 13:59:51 +0200
From:   Simon Horman <simon.horman@corigine.com>
To:     David Howells <dhowells@redhat.com>
Cc:     netdev@vger.kernel.org, Kenny Ho <Kenny.Ho@amd.com>,
        Marc Dionne <marc.dionne@auristor.com>,
        Andrew Lunn <andrew@lunn.ch>,
        David Laight <David.Laight@aculab.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, linux-afs@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH net] rxrpc: Truncate UTS_RELEASE for rxrpc version
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On Fri, May 26, 2023 at 12:34:54PM +0100, David Howells wrote:
>     
> UTS_RELEASE has a maximum length of 64 which can cause rxrpc_version to
> exceed the 65 byte message limit.
> 
> Per the rx spec[1]: "If a server receives a packet with a type value of 13,
> and the client-initiated flag set, it should respond with a 65-byte payload
> containing a string that identifies the version of AFS software it is
> running."
> 
> The current implementation causes a compile error when WERROR is turned on
> and/or UTS_RELEASE exceeds the length of 49 (making the version string more
> than 64 characters).
> 
> Fix this by generating the string during module initialisation and limiting
> the UTS_RELEASE segment of the string does not exceed 49 chars.  We need to
> make sure that the 64 bytes includes "linux-" at the front and " AF_RXRPC"
> at the back as this may be used in pattern matching.
> 
> Fixes: 44ba06987c0b ("RxRPC: Handle VERSION Rx protocol packets")
> Reported-by: Kenny Ho <Kenny.Ho@amd.com>
> Link: https://lore.kernel.org/r/20230523223944.691076-1-Kenny.Ho@amd.com/
> Signed-off-by: David Howells <dhowells@redhat.com>
> Acked-by: Kenny Ho <Kenny.Ho@amd.com>
> cc: Marc Dionne <marc.dionne@auristor.com>
> cc: Andrew Lunn <andrew@lunn.ch>
> cc: David Laight <David.Laight@ACULAB.COM>
> cc: "David S. Miller" <davem@davemloft.net>
> cc: Eric Dumazet <edumazet@google.com>
> cc: Jakub Kicinski <kuba@kernel.org>
> cc: Paolo Abeni <pabeni@redhat.com>
> cc: linux-afs@lists.infradead.org
> cc: netdev@vger.kernel.org
> Link: https://web.mit.edu/kolya/afs/rx/rx-spec [1]

Reviewed-by: Simon Horman <simon.horman@corigine.com>