From patchwork Wed May 29 11:55:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Stephan X-Patchwork-Id: 13678740 Received: from mail-wr1-f66.google.com (mail-wr1-f66.google.com [209.85.221.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 243BC14B973 for ; Wed, 29 May 2024 11:55:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.66 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716983760; cv=none; b=M2tF69yex4u8ZMfquYIBGQIOjG5AA8C46DQeCTFErdloj7N8+2+OcyHlTcwL9Hy2RV4d0HVBfcQFtD6Yyb5EjBcY29st6ndSrPMet3YW7hyxBTw97XTGXyBWZYAm0T7Ve6wK6fCvrBAdj1lzJWTwqZpOjUnH+4cI4jM3/sqeQBY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716983760; c=relaxed/simple; bh=wFaV86ck7QF8ggW3rB5WVf3ZtFyBTjaT7frcFvGnbMA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=Cf6iJxl7K++dC8QW6d0jeQGMN74X/Q0qTVJJumy0q5WuPCBjdNcF4/jw1dJdvo5A6hrpyjkFtjgnDoZr9LXd8ng1CUZFeddbQZZms3bqB7nt8Sztd8JtetJyj/R/XQFjW097QbVlirY+iOh7//Xs3dE0e4QvwMeSuUb6n2G2pi0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com; spf=pass smtp.mailfrom=baylibre.com; dkim=pass (2048-bit key) header.d=baylibre-com.20230601.gappssmtp.com header.i=@baylibre-com.20230601.gappssmtp.com header.b=gbmxHoSK; arc=none smtp.client-ip=209.85.221.66 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=baylibre.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=baylibre-com.20230601.gappssmtp.com header.i=@baylibre-com.20230601.gappssmtp.com header.b="gbmxHoSK" Received: by mail-wr1-f66.google.com with SMTP id ffacd0b85a97d-354f51ac110so1974635f8f.0 for ; Wed, 29 May 2024 04:55:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20230601.gappssmtp.com; s=20230601; t=1716983755; x=1717588555; darn=vger.kernel.org; h=cc:to:message-id:content-transfer-encoding:mime-version:subject :date:from:from:to:cc:subject:date:message-id:reply-to; bh=f9FUeFgYpsWXF3MFE7xmBZbQGZ+/K1H8MVPPwiFhTR4=; b=gbmxHoSKnjF20jU0HewqmeiCAppoFKjki/VZ6wBPRQDipQJUGw8BB1L09ffR41Aqvf UmX1ZYGSBR8jwAn0Y9TbTk+XumptqrfkSyEoFZJUhq/8AERMppynjRo/um24bOPYZmku G+XLEYyKUxumGwIIzasQcRd3Lu8uEVpu9HhSwbOOoZRerFZeHf39P/mEdMkBmHXWP9of iMW2iQGjccqmtkt6vB3niHlhpFWCmry6cmyIHz6VQd5ISxjnWBWVGumIuzPJa3wKvX6p u3NRsKXOiv0W8WA4G0HE2yBlsGLK9rlqh70VClPu4QqRZLcvj2bcaWuVQGAjtnLl4ozJ rfnw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1716983755; x=1717588555; h=cc:to:message-id:content-transfer-encoding:mime-version:subject :date:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=f9FUeFgYpsWXF3MFE7xmBZbQGZ+/K1H8MVPPwiFhTR4=; b=puHT+hz8TJFrxM1rbfUJ8uuAbqOvd8CWoJpfqjDeJBg3h5fOc0wuqMjosj+7fE4VWD bR3cqmxkVkKS0p62xvsTfPnmXwrLFHVI/e3BBpmKgb1dBhfcv/pJc5/e6Uz+hp4Tdcm3 Sb4MJ5Q7a4lVVwFYRiItH24zb671sgwPHGSVcumUu6DuP2FE+f1nIpoqYMyPG9ceCzfA BwfPyxoQH7/Ak/StcL9+3GtKGm9DEDkbkx4bd+WpeXynpOKqPVIVSP7B/hQMmHPioh3f fPueDIq63B0qs0fLzfVt9+YGhrTbUQV9v31whQtG+318ZQcEcvBBpkw3xRKN1DAH0QMh 8YNA== X-Gm-Message-State: AOJu0YxE5tnl8SLP/VGTCtm6Ud+Gy8WgmINwu9Qpj9yDcFWtpZg0UCgv YQ9NAJJyzD71zjESwLUzVdEgVljHAmKOqxJRVS5wMyheLZIPxVfk/LT8tmG/JJc= X-Google-Smtp-Source: AGHT+IFmFZnnN8czMqY8uLukaazrDK7oBtqJXR5sTBMOCV4ypMULcy6vjSsi/NnB59THLYsQFx6A6w== X-Received: by 2002:a5d:4089:0:b0:355:7e4:3cfb with SMTP id ffacd0b85a97d-3552f4fd798mr12389882f8f.23.1716983755303; Wed, 29 May 2024 04:55:55 -0700 (PDT) Received: from [192.168.1.63] ([2a02:842a:d52e:6101:6fd0:6c4:5d68:f0a5]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-35579d7de7esm14482339f8f.14.2024.05.29.04.55.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 May 2024 04:55:55 -0700 (PDT) From: Julien Stephan Date: Wed, 29 May 2024 13:55:52 +0200 Subject: [PATCH v2] driver: iio: add missing checks on iio_info's callback access Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240529-iio-core-fix-segfault-v2-1-7b5a5fa6853f@baylibre.com> X-B4-Tracking: v=1; b=H4sIAMgXV2YC/3WNwQ6CMBBEf4Xs2TW0Yqie/A/DYVu2sAlS0yKRE P7dSuLR45vJvFkhcRROcC1WiDxLkjBm0IcCXE9jxyhtZtClrsqzNigS0IXI6OWNiTtPr2FCorq yXDNzRZC3z8i53733JnMvaQpx2W9m9U1/xssf46xQYe29smSMak/mZmkZxEY+uvCAZtu2D3UCX 9i9AAAA To: Jonathan Cameron , Lars-Peter Clausen Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Nuno Sa , Julien Stephan X-Mailer: b4 0.13.0 Some callbacks from iio_info structure are accessed without any check, so if a driver doesn't implement them trying to access the corresponding sysfs entries produce a kernel oops such as: [ 2203.527791] Unable to handle kernel NULL pointer dereference at virtual address 00000000 when execute [...] [ 2203.783416] Call trace: [ 2203.783429] iio_read_channel_info_avail from dev_attr_show+0x18/0x48 [ 2203.789807] dev_attr_show from sysfs_kf_seq_show+0x90/0x120 [ 2203.794181] sysfs_kf_seq_show from seq_read_iter+0xd0/0x4e4 [ 2203.798555] seq_read_iter from vfs_read+0x238/0x2a0 [ 2203.802236] vfs_read from ksys_read+0xa4/0xd4 [ 2203.805385] ksys_read from ret_fast_syscall+0x0/0x54 [ 2203.809135] Exception stack(0xe0badfa8 to 0xe0badff0) [ 2203.812880] dfa0: 00000003 b6f10f80 00000003 b6eab000 00020000 00000000 [ 2203.819746] dfc0: 00000003 b6f10f80 7ff00000 00000003 00000003 00000000 00020000 00000000 [ 2203.826619] dfe0: b6e1bc88 bed80958 b6e1bc94 b6e1bcb0 [ 2203.830363] Code: bad PC value [ 2203.832695] ---[ end trace 0000000000000000 ]--- Reviewed-by: Nuno Sa Signed-off-by: Julien Stephan --- Changes in v2: - crop dmesg log to show only pertinent info and reduce commit message - Link to v1: https://lore.kernel.org/r/20240529-iio-core-fix-segfault-v1-1-7ff1ba881d38@baylibre.com --- drivers/iio/industrialio-core.c | 7 ++++++- drivers/iio/industrialio-event.c | 9 +++++++++ drivers/iio/inkern.c | 16 +++++++++++----- 3 files changed, 26 insertions(+), 6 deletions(-) --- base-commit: 409b6d632f5078f3ae1018b6e43c32f2e12f6736 change-id: 20240528-iio-core-fix-segfault-aa74be7eee4a Best regards, diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index fa7cc051b4c4..2f185b386949 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -758,9 +758,11 @@ static ssize_t iio_read_channel_info(struct device *dev, INDIO_MAX_RAW_ELEMENTS, vals, &val_len, this_attr->address); - else + else if (indio_dev->info->read_raw) ret = indio_dev->info->read_raw(indio_dev, this_attr->c, &vals[0], &vals[1], this_attr->address); + else + return -EINVAL; if (ret < 0) return ret; @@ -842,6 +844,9 @@ static ssize_t iio_read_channel_info_avail(struct device *dev, int length; int type; + if (!indio_dev->info->read_avail) + return -EINVAL; + ret = indio_dev->info->read_avail(indio_dev, this_attr->c, &vals, &type, &length, this_attr->address); diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c index 910c1f14abd5..a64f8fbac597 100644 --- a/drivers/iio/industrialio-event.c +++ b/drivers/iio/industrialio-event.c @@ -285,6 +285,9 @@ static ssize_t iio_ev_state_store(struct device *dev, if (ret < 0) return ret; + if (!indio_dev->info->write_event_config) + return -EINVAL; + ret = indio_dev->info->write_event_config(indio_dev, this_attr->c, iio_ev_attr_type(this_attr), iio_ev_attr_dir(this_attr), val); @@ -300,6 +303,9 @@ static ssize_t iio_ev_state_show(struct device *dev, struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); int val; + if (!indio_dev->info->read_event_config) + return -EINVAL; + val = indio_dev->info->read_event_config(indio_dev, this_attr->c, iio_ev_attr_type(this_attr), iio_ev_attr_dir(this_attr)); @@ -318,6 +324,9 @@ static ssize_t iio_ev_value_show(struct device *dev, int val, val2, val_arr[2]; int ret; + if (!indio_dev->info->read_event_value) + return -EINVAL; + ret = indio_dev->info->read_event_value(indio_dev, this_attr->c, iio_ev_attr_type(this_attr), iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr), diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c index 52d773261828..74f87f6ac390 100644 --- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -560,9 +560,11 @@ static int iio_channel_read(struct iio_channel *chan, int *val, int *val2, vals, &val_len, info); *val = vals[0]; *val2 = vals[1]; - } else { + } else if (chan->indio_dev->info->read_raw) { ret = chan->indio_dev->info->read_raw(chan->indio_dev, chan->channel, val, val2, info); + } else { + return -EINVAL; } return ret; @@ -753,8 +755,10 @@ static int iio_channel_read_avail(struct iio_channel *chan, if (!iio_channel_has_available(chan->channel, info)) return -EINVAL; - return chan->indio_dev->info->read_avail(chan->indio_dev, chan->channel, - vals, type, length, info); + if (chan->indio_dev->info->read_avail) + return chan->indio_dev->info->read_avail(chan->indio_dev, chan->channel, + vals, type, length, info); + return -EINVAL; } int iio_read_avail_channel_attribute(struct iio_channel *chan, @@ -917,8 +921,10 @@ EXPORT_SYMBOL_GPL(iio_get_channel_type); static int iio_channel_write(struct iio_channel *chan, int val, int val2, enum iio_chan_info_enum info) { - return chan->indio_dev->info->write_raw(chan->indio_dev, - chan->channel, val, val2, info); + if (chan->indio_dev->info->write_raw) + return chan->indio_dev->info->write_raw(chan->indio_dev, + chan->channel, val, val2, info); + return -EINVAL; } int iio_write_channel_attribute(struct iio_channel *chan, int val, int val2,