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 42EE12FE042; Tue, 31 Mar 2026 17:05:32 +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=1774976732; cv=none; b=J0R9YOEs9G4D9STtNKCMiFEs9DM8L3sibIdT0jO/GvqBF7Tv8r/PJ6RvzOktemaaVECWO6A4fDXNLBSg1u5DtiYxa1M7+RVS7ldkIVlXmMX7NNQfhAsZmt6fOnWLhJQqXkCD8IJUTZBDtTXBKkH0h+VZwdTlxPLg61nrUOxhdy4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774976732; c=relaxed/simple; bh=qT5T/1oJvmvbg5+966MPSjOCrHNfjFcNiEgma4OFqR8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iiJ05GYDWhOmzF38HI6S8k+Gwx1Uk11OvoRVidkddI+bdKEPmcwp7JKPij4Poe+pTM8DtjhkNdB+Bb9ZnDHTc50gzErVeJmo4Qpqz4i7uHorHQ0YflHkQJgpJJp83TzfNZ3GpNYeHGgngKNUIh30XwyZUuuOWztqd8RzDvYLQqs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=b994GGNt; 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="b994GGNt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCEA4C19423; Tue, 31 Mar 2026 17:05:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774976732; bh=qT5T/1oJvmvbg5+966MPSjOCrHNfjFcNiEgma4OFqR8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=b994GGNtNTi80p2TttC42Q/RcQQPye8WLaUa7Faz/vhJpDZ/OezqH1Gxth78HTiDQ dW64Qkt2Qsv3r7VAlTU15vl0ma4LirCTPRCfVXuLxkdzgY/hf4WeGsT3kmLfVFb2WB hGhJ1Evc+wRUzdcPIIkvbwNST4VmbRBNDNdmrkFY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Gui-Dong Han , Danilo Krummrich , Mark Brown , Sasha Levin Subject: [PATCH 6.18 163/309] spi: use generic driver_override infrastructure Date: Tue, 31 Mar 2026 18:21:06 +0200 Message-ID: <20260331161759.466030180@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260331161753.468533260@linuxfoundation.org> References: <20260331161753.468533260@linuxfoundation.org> User-Agent: quilt/0.69 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-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Danilo Krummrich [ Upstream commit cc34d77dd48708d810c12bfd6f5bf03304f6c824 ] When a driver is probed through __driver_attach(), the bus' match() callback is called without the device lock held, thus accessing the driver_override field without a lock, which can cause a UAF. Fix this by using the driver-core driver_override infrastructure taking care of proper locking internally. Note that calling match() from __driver_attach() without the device lock held is intentional. [1] Also note that we do not enable the driver_override feature of struct bus_type, as SPI - in contrast to most other buses - passes "" to sysfs_emit() when the driver_override pointer is NULL. Thus, printing "\n" instead of "(null)\n". Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1] Reported-by: Gui-Dong Han Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789 Fixes: 5039563e7c25 ("spi: Add driver_override SPI device attribute") Signed-off-by: Danilo Krummrich Link: https://patch.msgid.link/20260324005919.2408620-12-dakr@kernel.org Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi.c | 19 +++++++------------ include/linux/spi/spi.h | 5 ----- 2 files changed, 7 insertions(+), 17 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 201b9569ce690..87d829d2a8427 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -50,7 +50,6 @@ static void spidev_release(struct device *dev) struct spi_device *spi = to_spi_device(dev); spi_controller_put(spi->controller); - kfree(spi->driver_override); free_percpu(spi->pcpu_statistics); kfree(spi); } @@ -73,10 +72,9 @@ static ssize_t driver_override_store(struct device *dev, struct device_attribute *a, const char *buf, size_t count) { - struct spi_device *spi = to_spi_device(dev); int ret; - ret = driver_set_override(dev, &spi->driver_override, buf, count); + ret = __device_set_driver_override(dev, buf, count); if (ret) return ret; @@ -86,13 +84,8 @@ static ssize_t driver_override_store(struct device *dev, static ssize_t driver_override_show(struct device *dev, struct device_attribute *a, char *buf) { - const struct spi_device *spi = to_spi_device(dev); - ssize_t len; - - device_lock(dev); - len = sysfs_emit(buf, "%s\n", spi->driver_override ? : ""); - device_unlock(dev); - return len; + guard(spinlock)(&dev->driver_override.lock); + return sysfs_emit(buf, "%s\n", dev->driver_override.name ?: ""); } static DEVICE_ATTR_RW(driver_override); @@ -376,10 +369,12 @@ static int spi_match_device(struct device *dev, const struct device_driver *drv) { const struct spi_device *spi = to_spi_device(dev); const struct spi_driver *sdrv = to_spi_driver(drv); + int ret; /* Check override first, and if set, only use the named driver */ - if (spi->driver_override) - return strcmp(spi->driver_override, drv->name) == 0; + ret = device_match_driver_override(dev, drv); + if (ret >= 0) + return ret; /* Attempt an OF style match */ if (of_driver_match_device(dev, drv)) diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index cb2c2df310899..fe9dd430cc03a 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -156,10 +156,6 @@ extern void spi_transfer_cs_change_delay_exec(struct spi_message *msg, * @modalias: Name of the driver to use with this device, or an alias * for that name. This appears in the sysfs "modalias" attribute * for driver coldplugging, and in uevents used for hotplugging - * @driver_override: If the name of a driver is written to this attribute, then - * the device will bind to the named driver and only the named driver. - * Do not set directly, because core frees it; use driver_set_override() to - * set or clear it. * @pcpu_statistics: statistics for the spi_device * @word_delay: delay to be inserted between consecutive * words of a transfer @@ -217,7 +213,6 @@ struct spi_device { void *controller_state; void *controller_data; char modalias[SPI_NAME_SIZE]; - const char *driver_override; /* The statistics */ struct spi_statistics __percpu *pcpu_statistics; -- 2.53.0