From nobody Thu Sep 4 03:33:48 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7123CC54EE9 for ; Tue, 13 Sep 2022 15:37:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236644AbiIMPhq (ORCPT ); Tue, 13 Sep 2022 11:37:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236545AbiIMPhU (ORCPT ); Tue, 13 Sep 2022 11:37:20 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DB4F80033; Tue, 13 Sep 2022 07:43:24 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 24F3361494; Tue, 13 Sep 2022 14:31:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3EFA9C433C1; Tue, 13 Sep 2022 14:31:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1663079466; bh=uNSfD+YJSHbwEa+qX173I2UYx9SbLW3ewT0J92EAxuE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d9UyOyLmD6S+iIX4l39b1GtgqVWtcbNQUrRay+pAWyP2NRDrCpXIYEXQB/UiOePaj X4hw96eIQLMRZCwpJ77FJL8VYniiZPgLsFojzFTgYX7wsKe1xiXOQC39+frtFtvdTx JtjILM/HmwIZtXIUoufT3PLpAm6HFczYBmVN4u+I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Armin Wolf , Guenter Roeck , Sasha Levin Subject: [PATCH 4.19 30/79] hwmon: (gpio-fan) Fix array out of bounds access Date: Tue, 13 Sep 2022 16:06:48 +0200 Message-Id: <20220913140350.348204695@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220913140348.835121645@linuxfoundation.org> References: <20220913140348.835121645@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Armin Wolf [ Upstream commit f233d2be38dbbb22299192292983037f01ab363c ] The driver does not check if the cooling state passed to gpio_fan_set_cur_state() exceeds the maximum cooling state as stored in fan_data->num_speeds. Since the cooling state is later used as an array index in set_fan_speed(), an array out of bounds access can occur. This can be exploited by setting the state of the thermal cooling device to arbitrary values, causing for example a kernel oops when unavailable memory is accessed this way. Example kernel oops: [ 807.987276] Unable to handle kernel paging request at virtual address ff= ffff80d0588064 [ 807.987369] Mem abort info: [ 807.987398] ESR =3D 0x96000005 [ 807.987428] EC =3D 0x25: DABT (current EL), IL =3D 32 bits [ 807.987477] SET =3D 0, FnV =3D 0 [ 807.987507] EA =3D 0, S1PTW =3D 0 [ 807.987536] FSC =3D 0x05: level 1 translation fault [ 807.987570] Data abort info: [ 807.987763] ISV =3D 0, ISS =3D 0x00000005 [ 807.987801] CM =3D 0, WnR =3D 0 [ 807.987832] swapper pgtable: 4k pages, 39-bit VAs, pgdp=3D00000000011650= 00 [ 807.987872] [ffffff80d0588064] pgd=3D0000000000000000, p4d=3D00000000000= 00000, pud=3D0000000000000000 [ 807.987961] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 807.987992] Modules linked in: cmac algif_hash aes_arm64 algif_skcipher = af_alg bnep hci_uart btbcm bluetooth ecdh_generic ecc 8021q garp stp llc sn= d_soc_hdmi_codec brcmfmac vc4 brcmutil cec drm_kms_helper snd_soc_core cfg8= 0211 snd_compress bcm2835_codec(C) snd_pcm_dmaengine syscopyarea bcm2835_is= p(C) bcm2835_v4l2(C) sysfillrect v4l2_mem2mem bcm2835_mmal_vchiq(C) raspber= rypi_hwmon sysimgblt videobuf2_dma_contig videobuf2_vmalloc fb_sys_fops vid= eobuf2_memops rfkill videobuf2_v4l2 videobuf2_common i2c_bcm2835 snd_bcm283= 5(C) videodev snd_pcm snd_timer snd mc vc_sm_cma(C) gpio_fan uio_pdrv_genir= q uio drm fuse drm_panel_orientation_quirks backlight ip_tables x_tables ip= v6 [ 807.988508] CPU: 0 PID: 1321 Comm: bash Tainted: G C 5.15= .56-v8+ #1575 [ 807.988548] Hardware name: Raspberry Pi 3 Model B Rev 1.2 (DT) [ 807.988574] pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE= =3D--) [ 807.988608] pc : set_fan_speed.part.5+0x34/0x80 [gpio_fan] [ 807.988654] lr : gpio_fan_set_cur_state+0x34/0x50 [gpio_fan] [ 807.988691] sp : ffffffc008cf3bd0 [ 807.988710] x29: ffffffc008cf3bd0 x28: ffffff80019edac0 x27: 00000000000= 00000 [ 807.988762] x26: 0000000000000000 x25: 0000000000000000 x24: ffffff80074= 7c920 [ 807.988787] x23: 000000000000000a x22: ffffff800369f000 x21: 00000000199= 9997c [ 807.988854] x20: ffffff800369f2e8 x19: ffffff8002ae8080 x18: 00000000000= 00000 [ 807.988877] x17: 0000000000000000 x16: 0000000000000000 x15: 000000559e2= 71b70 [ 807.988938] x14: 0000000000000000 x13: 0000000000000000 x12: 00000000000= 00000 [ 807.988960] x11: 0000000000000000 x10: ffffffc008cf3c20 x9 : ffffffcfb60= c741c [ 807.989018] x8 : 000000000000000a x7 : 00000000ffffffc9 x6 : 00000000000= 00009 [ 807.989040] x5 : 000000000000002a x4 : 0000000000000000 x3 : ffffff80036= 9f2e8 [ 807.989062] x2 : 000000000000e780 x1 : 0000000000000001 x0 : ffffff80d05= 88060 [ 807.989084] Call trace: [ 807.989091] set_fan_speed.part.5+0x34/0x80 [gpio_fan] [ 807.989113] gpio_fan_set_cur_state+0x34/0x50 [gpio_fan] [ 807.989199] cur_state_store+0x84/0xd0 [ 807.989221] dev_attr_store+0x20/0x38 [ 807.989262] sysfs_kf_write+0x4c/0x60 [ 807.989282] kernfs_fop_write_iter+0x130/0x1c0 [ 807.989298] new_sync_write+0x10c/0x190 [ 807.989315] vfs_write+0x254/0x378 [ 807.989362] ksys_write+0x70/0xf8 [ 807.989379] __arm64_sys_write+0x24/0x30 [ 807.989424] invoke_syscall+0x4c/0x110 [ 807.989442] el0_svc_common.constprop.3+0xfc/0x120 [ 807.989458] do_el0_svc+0x2c/0x90 [ 807.989473] el0_svc+0x24/0x60 [ 807.989544] el0t_64_sync_handler+0x90/0xb8 [ 807.989558] el0t_64_sync+0x1a0/0x1a4 [ 807.989579] Code: b9403801 f9402800 7100003f 8b35cc00 (b9400416) [ 807.989627] ---[ end trace 8ded4c918658445b ]--- Fix this by checking the cooling state and return an error if it exceeds the maximum cooling state. Tested on a Raspberry Pi 3. Fixes: b5cf88e46bad ("(gpio-fan): Add thermal control hooks") Signed-off-by: Armin Wolf Link: https://lore.kernel.org/r/20220830011101.178843-1-W_Armin@gmx.de Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin --- drivers/hwmon/gpio-fan.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c index a3974cddef079..534a175a6e4cf 100644 --- a/drivers/hwmon/gpio-fan.c +++ b/drivers/hwmon/gpio-fan.c @@ -404,6 +404,9 @@ static int gpio_fan_set_cur_state(struct thermal_coolin= g_device *cdev, if (!fan_data) return -EINVAL; =20 + if (state >=3D fan_data->num_speed) + return -EINVAL; + set_fan_speed(fan_data, state); return 0; } --=20 2.35.1