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Thu, 27 Aug 2026 06:12:28 -0700 (PDT) Received: from Default ([2409:40f4:100d:ce02:df7d:ac3d:4a05:c45a]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-3283fa89e8fsm28978904eec.8.2026.08.27.06.12.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 27 Aug 2026 06:12:27 -0700 (PDT) From: Jeffin Philip To: tiwai@suse.de Cc: linux-kernel@vger.kernel.org, linux-sound@vger.kernel.org Subject: Re: [PATCH] ALSA: control: Don't add invalid kcontrols to LED layer Date: Thu, 27 Aug 2026 18:42:11 +0530 Message-ID: <20260827131211.11946-1-jeffinphilip14@gmail.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260827113951.893291-1-tiwai@suse.de> References: <20260827113951.893291-1-tiwai@suse.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On 8/27/26 13:39, Takashi Iwai wrote: >The kcontrol LED state layer tries to track the all associated >kcontrol elements with naive assumptions that they are readable. >But one can create a write-only element that has no get callback (even >a user element can do it), and this may lead to a NULL dereference at >the call chain of snd_ctl_led_notify(), as found by syzkaller. > >For avoiding the Oops, add a sanity check of the kcontrol's info and >get callbacks, and just skip the invalid kcontrols before assigning >the kctl to the LED layer. I don't think a user can attach a device via sysfs without root permissions, (correct me if I am wrong). I attempted it on my device and got Permission Denied. But otherwise, seems to be okay. Thanks, Jeffin.