From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A67B1F7594; Tue, 3 Dec 2024 16:09:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733242163; cv=none; b=N1T5knhbGawdNQmsznZA4SGUNk83GxDZYLrjPGIRfwY/WQD1XTetUEh4VGss+GtSzcdg5uLw8k2qptDskCImLGtHPs8vRfy3jDQD3gdNfUKP5Tkt/jC1qNO3jrclJGXAFYwBydUacaaRJJsZIJGvqKS57BWOGdw8Ej+LHpAw15Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733242163; c=relaxed/simple; bh=43HlLxf8r9McxXEq4EYFM4jcW/C0+ox97PiGNn9bb34=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=pw3ae/gbKlb2esQLZBdxmGkEv2Fl3zXkzq/n65xOKJPCl+3fCfyojqYfgKRt1X6MVto/ZUGQ9hpVbDCuSiiRF3e3iwdUkim057TAD9/Mgn2+Id6QrSFOQL7zO05je12jCYORLsfa7DYMWWCL5OTPhnDGlfyda3Y+KoqG/c5sk4Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Nd7eOmR0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Nd7eOmR0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8AE4AC4CECF; Tue, 3 Dec 2024 16:09:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1733242163; bh=43HlLxf8r9McxXEq4EYFM4jcW/C0+ox97PiGNn9bb34=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nd7eOmR0iZZBJdhpVvnafsXUqTPkL6pUPongxmyJoeOEzhohm/R6JfwSL9Q4IY9y+ qI99nsdvhITx4sHcatutbnM8dr97gbShZnnW9+36Pn2VQJtj3yCaGIQS3VPQuQGlyo l0nEF1z1aBxFZ0zmmPq9MW9z4ZDKS8Vmlr61+p4k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Beno=C3=AEt=20Sevens?= , Takashi Iwai Subject: [PATCH 6.12 626/826] ALSA: usb-audio: Fix out of bounds reads when finding clock sources Date: Tue, 3 Dec 2024 15:45:53 +0100 Message-ID: <20241203144808.171907382@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241203144743.428732212@linuxfoundation.org> References: <20241203144743.428732212@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Takashi Iwai commit a3dd4d63eeb452cfb064a13862fb376ab108f6a6 upstream. The current USB-audio driver code doesn't check bLength of each descriptor at traversing for clock descriptors. That is, when a device provides a bogus descriptor with a shorter bLength, the driver might hit out-of-bounds reads. For addressing it, this patch adds sanity checks to the validator functions for the clock descriptor traversal. When the descriptor length is shorter than expected, it's skipped in the loop. For the clock source and clock multiplier descriptors, we can just check bLength against the sizeof() of each descriptor type. OTOH, the clock selector descriptor of UAC2 and UAC3 has an array of bNrInPins elements and two more fields at its tail, hence those have to be checked in addition to the sizeof() check. Reported-by: Benoît Sevens Cc: Link: https://lore.kernel.org/20241121140613.3651-1-bsevens@google.com Link: https://patch.msgid.link/20241125144629.20757-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/clock.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) --- a/sound/usb/clock.c +++ b/sound/usb/clock.c @@ -36,6 +36,12 @@ union uac23_clock_multiplier_desc { struct uac_clock_multiplier_descriptor v3; }; +/* check whether the descriptor bLength has the minimal length */ +#define DESC_LENGTH_CHECK(p, proto) \ + ((proto) == UAC_VERSION_3 ? \ + ((p)->v3.bLength >= sizeof((p)->v3)) : \ + ((p)->v2.bLength >= sizeof((p)->v2))) + #define GET_VAL(p, proto, field) \ ((proto) == UAC_VERSION_3 ? (p)->v3.field : (p)->v2.field) @@ -58,6 +64,8 @@ static bool validate_clock_source(void * { union uac23_clock_source_desc *cs = p; + if (!DESC_LENGTH_CHECK(cs, proto)) + return false; return GET_VAL(cs, proto, bClockID) == id; } @@ -65,13 +73,27 @@ static bool validate_clock_selector(void { union uac23_clock_selector_desc *cs = p; - return GET_VAL(cs, proto, bClockID) == id; + if (!DESC_LENGTH_CHECK(cs, proto)) + return false; + if (GET_VAL(cs, proto, bClockID) != id) + return false; + /* additional length check for baCSourceID array (in bNrInPins size) + * and two more fields (which sizes depend on the protocol) + */ + if (proto == UAC_VERSION_3) + return cs->v3.bLength >= sizeof(cs->v3) + cs->v3.bNrInPins + + 4 /* bmControls */ + 2 /* wCSelectorDescrStr */; + else + return cs->v2.bLength >= sizeof(cs->v2) + cs->v2.bNrInPins + + 1 /* bmControls */ + 1 /* iClockSelector */; } static bool validate_clock_multiplier(void *p, int id, int proto) { union uac23_clock_multiplier_desc *cs = p; + if (!DESC_LENGTH_CHECK(cs, proto)) + return false; return GET_VAL(cs, proto, bClockID) == id; }