From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793893564; b=mKzWdag4HqI3WR+iFaqFWykdYajuDMmlwNbu4nYO44M375dPWmz4Ajn7TmMogO4IIQp3 yAToeOETFlVcshRsAzJb8s3o+4MoT39QeJVrrOYWbiJZTFURqVLptgWAsUVOU9Espq4oP mffFep++DPxy5H07oBVlUtYwwSD4moaWT5M4yNBwoyHf5Mq/wdCU3tl+iysZSoU8JP2rz fEUgStQ4lkXiaPA6RoOsXdZuPC0KyfNcL3JH3xBMU2m0dcA6dwL0jMT11/6GUM5lzTgEf dtR1uJj4KpX/wsF+KHLXDHjAEbUEuD9r/mMWqSQHUJPUcK23rHDP9hUPOLUxRkEvoqw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793893564; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=TEExI0wyKCh5UrhCecRJ7HynlA0hRxBVTphCMFuZjBM=; b=LgHDdG2OFfxTULNCnC9hKro0Wbaoslb7+0dAZW7UnngSYJKG7PYPC8h1cG3ioqH50e9K rYfZnH6WU5tiGf15cky3yhJICeXeHtqn0V1w/uVgB9tSTpbNMsdcUbWAMPq4IC6vx20J2 U6dxzauleYlhlOeAYXa9PzRx4a3aL7Zh4ENNOACGbL0ddCDEnmiH0z0UN6bLcwq5sPGBc dkCqqATs6MZkvKh8yTMfzK89pvqd+gawzijoUrqsMSrHg8/Zqq2pkVAVx5cJCyy5sZwTl EQ5H2eH8fkwLgyrY8R47cQU4pDu0En0mYLpz5SkWyGgu++xAzaN3zkfZQRgma2KXI1A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ifdAfxYL; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with UTF8SMTPS id 7977E606D834; Thu, 5 Nov 2026 15:46:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ifdAfxYL Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id 7876F1F000C1; Thu, 5 Nov 2026 15:46:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793893564; bh=TEExI0wyKCh5UrhCecRJ7HynlA0hRxBVTphCMFuZjBM=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=ifdAfxYLh+GoaGTXqEC0N5Mc1S6FzqY7oRvV92Sqpk8TeKMYsVG6WafXtr5AjcBJq DBgFHcvhnnkSM9mwN2MDAkMhLRy+q/MzKfSSu0Hfg1+OPWYGUlEZAIGRpAijE5pwKS GKtckZy/si3vrf4i4MGr/FUdNXbRBTmJlL/G+M1uo06PWLGLVF8EF48TDzGObepLD/ R+eGMaXX23EqNY06AslovgPYTziSDewOH88X2Vm1bbyjB8PiNpKWf5Mt48ka2y/liA iG1NAkENvzvygZl9inlAsrRGNXz/GsqmEe2EDGOzl/z4/H5iDBsii7vKgnFIPnhVhH r3RrWIhUVqMeA== Date: Thu, 5 Nov 2026 16:46:01 +0100 From: Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= To: Lee Jones Cc: Thierry Reding , Jonathan Hunter , Mikko Perttunen , Sascha Hauer , Sandipan Patra , linux-pwm@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 1/8] pwm: tegra: Prevent 32-bit period truncation and division by zero Message-ID: References: <20261105143847.2559586-1-lee@kernel.org> <20261105143847.2559586-2-lee@kernel.org> X-Mailing-List: linux-tegra@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="5nxrbirnwnmd4xu2" Content-Disposition: inline In-Reply-To: <20261105143847.2559586-2-lee@kernel.org> --5nxrbirnwnmd4xu2 Content-Type: text/plain; protected-headers=v1; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: [PATCH 1/8] pwm: tegra: Prevent 32-bit period truncation and division by zero MIME-Version: 1.0 Hello Lee, On Thu, Nov 05, 2026 at 02:38:03PM +0000, Lee Jones wrote: > tegra_pwm_apply() passes the 64-bit state->duty_cycle and state->period > values into tegra_pwm_config(), which accepts signed 32-bit int > parameters and performs DIV_ROUND_CLOSEST_ULL(c, period_ns) before > validating period_ns against pc->min_period_ns. If a consumer requests > a period that is a non-zero multiple of 2^32 nanoseconds, period_ns > truncates to zero and triggers a divide-by-zero panic. >=20 > Widen duty_ns and period_ns to u64 and validate that period_ns lies > within [pc->min_period_ns, U32_MAX] prior to dividing by period_ns. >=20 > Fixes: 1d7796bdb63a ("pwm: tegra: Support dynamic clock frequency configu= ration") > Fixes: fd3ddd4355c0 ("pwm: tegra: Implement .apply() callback") > Closes: https://sashiko.dev/#/bug/linux-5c5b97d6-4da6-4d06-9dc7-957419dcd= 832 > Cc: stable@vger.kernel.org > Signed-off-by: Lee Jones This is already addressed in 9ad5602d4943 ("pwm: tegra: Fix value discarding for duty and period") which is next-20261102 and later. Best regards Uwe --5nxrbirnwnmd4xu2 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEP4GsaTp6HlmJrf7Tj4D7WH0S/k4FAmrspLcACgkQj4D7WH0S /k7IZAgAgTxBFVmi5VNODULNSO0AzIE/XByrLnv9QPXpoGtE3u0fxn0SqZ8wdLaO zboASSjsv6LW2VhdvVNNouW6XmjvAVtBXq073REQWGEEWjqbkZ805Hc9CRqgKbS8 RimnYb03FQPAOnXbH3zgXI7WOxw5+4Q42FHW7MKWR/65rq8sPRfklO77fm7oSDn5 jjSz5NN2ES6hvDHjGAdp4/dOC7X+7ZKFguO0eOYolk7E5mmPJ1MiIKBx3AgcDkh7 YHw/xMpIWcaQk1mvbkPIcyUIDdW7jA+l9hpwq/6hnhBAuEpkOkxNcNlRQfq9XHOn DPYJUkv/NkCqUKrSSQg/yc07PydLug== =3cdS -----END PGP SIGNATURE----- --5nxrbirnwnmd4xu2--