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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-49e83db9102sm64812065e9.12.2026.09.16.02.29.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Sep 2026 02:29:53 -0700 (PDT) Date: Wed, 16 Sep 2026 10:29:51 +0100 From: David Laight To: Kees Cook Cc: Bill Wendling , linux-kernel@vger.kernel.org, codemender-patching+linux@google.com, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Peter Griffin , Linus Walleij , "Martin K. Petersen" , Trond Myklebust , Anna Schumaker , Jiri Pirko , Simon Horman , Chuck Lever , Jeff Layton , NeilBrown , Olga Kornievskaia , Dai Ngo , Tom Talpey , Jaroslav Kysela , Takashi Iwai , Andrew Morton , "Mike Rapoport (Microsoft)" , Kanglong Wang , Tiezhu Yang , Qiang Ma , Randy Dunlap , Pengpeng Hou , Ard Biesheuvel , Breno Leitao , Thorsten Blum , Greg Kroah-Hartman , Dmitry Baryshkov , Johan Hovold , Cen Zhang , =?UTF-8?B?Q8Ohc3Np?= =?UTF-8?B?bw==?= Gabriel , Rong Zhang , linux-input@vger.kernel.org, linux-media@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, devicetree@vger.kernel.org, linux-gpio@vger.kernel.org, devel@lists.orangefs.org, linux-hardening@vger.kernel.org, linux-sound@vger.kernel.org Subject: Re: [PATCH 01/28] ALSA: ac97: Refactor snd_ac97_get_name() to use snprintf() Message-ID: <20260916102532.4b881a25@pumpkin> In-Reply-To: <202609151134.361FEA04@keescook> References: <20260915081910.4142719-1-morbo@google.com> <20260915081910.4142719-2-morbo@google.com> <202609151134.361FEA04@keescook> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 15 Sep 2026 11:39:34 -0700 Kees Cook wrote: (I've just juked a lot of the 'reply to' list - too long to gmail.) > On Tue, Sep 15, 2026 at 08:18:18AM +0000, Bill Wendling wrote: > > --- a/sound/pci/ac97/ac97_codec.c > > +++ b/sound/pci/ac97/ac97_codec.c > > @@ -1850,10 +1850,12 @@ void snd_ac97_get_name(struct snd_ac97 *ac97, unsigned int id, char *name, > > > > pid = look_for_codec_id(snd_ac97_codec_ids, id); > > if (pid) { > > - strlcat(name, " ", maxlen); > > - strlcat(name, pid->name, maxlen); > > + int l = strlen(name); > > + > > if (pid->mask != 0xffffffff) > > - sprintf(name + strlen(name), " rev %u", id & ~pid->mask); > > + snprintf(name + l, maxlen - l, " %s rev %u", pid->name, id & ~pid->mask); > > + else > > + snprintf(name + l, maxlen - l, " %s", pid->name); > > if (ac97 && pid->patch) { > > if ((modem && (pid->flags & AC97_MODEM_PATCH)) || > > (! modem && ! (pid->flags & AC97_MODEM_PATCH))) > > @@ -1861,6 +1863,7 @@ void snd_ac97_get_name(struct snd_ac97 *ac97, unsigned int id, char *name, > > } > > } else { > > int l = strlen(name); > > + > > snprintf(name + l, maxlen - l, " id %x", id & 0xff); > > } > > } > > I'd rather not open-code the length math here. Can't we use seq_buf() > instead? > Or just use the length returned by the strscpy() call that wrote the initial part of name[]. The return the name length so the callers don't have to use strcat() themselves. Replacing strlcat() with strlen() and a copy is just pointless. David