The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x f7d306b47a24367302bd4fe846854e07752ffcd9 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024121041-floss-compactor-3b56@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From f7d306b47a24367302bd4fe846854e07752ffcd9 Mon Sep 17 00:00:00 2001 From: Dan Carpenter dan.carpenter@linaro.org Date: Mon, 2 Dec 2024 15:57:54 +0300 Subject: [PATCH] ALSA: usb-audio: Fix a DMA to stack memory bug

The usb_get_descriptor() function does DMA so we're not allowed to use a stack buffer for that. Doing DMA to the stack is not portable all architectures. Move the "new_device_descriptor" from being stored on the stack and allocate it with kmalloc() instead.

Fixes: b909df18ce2a ("ALSA: usb-audio: Fix potential out-of-bound accesses for Extigy and Mbox devices") Cc: stable@kernel.org Signed-off-by: Dan Carpenter dan.carpenter@linaro.org Link: https://patch.msgid.link/60e3aa09-039d-46d2-934c-6f123026c2eb@stanley.mounta... Signed-off-by: Takashi Iwai tiwai@suse.de

diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c index 8bc959b60be3..7c9d352864da 100644 --- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -555,7 +555,7 @@ int snd_usb_create_quirk(struct snd_usb_audio *chip, static int snd_usb_extigy_boot_quirk(struct usb_device *dev, struct usb_interface *intf) { struct usb_host_config *config = dev->actconfig; - struct usb_device_descriptor new_device_descriptor; + struct usb_device_descriptor *new_device_descriptor __free(kfree) = NULL; int err;

if (le16_to_cpu(get_cfg_desc(config)->wTotalLength) == EXTIGY_FIRMWARE_SIZE_OLD || @@ -566,15 +566,19 @@ static int snd_usb_extigy_boot_quirk(struct usb_device *dev, struct usb_interfac 0x10, 0x43, 0x0001, 0x000a, NULL, 0); if (err < 0) dev_dbg(&dev->dev, "error sending boot message: %d\n", err); + + new_device_descriptor = kmalloc(sizeof(*new_device_descriptor), GFP_KERNEL); + if (!new_device_descriptor) + return -ENOMEM; err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, - &new_device_descriptor, sizeof(new_device_descriptor)); + new_device_descriptor, sizeof(*new_device_descriptor)); if (err < 0) dev_dbg(&dev->dev, "error usb_get_descriptor: %d\n", err); - if (new_device_descriptor.bNumConfigurations > dev->descriptor.bNumConfigurations) + if (new_device_descriptor->bNumConfigurations > dev->descriptor.bNumConfigurations) dev_dbg(&dev->dev, "error too large bNumConfigurations: %d\n", - new_device_descriptor.bNumConfigurations); + new_device_descriptor->bNumConfigurations); else - memcpy(&dev->descriptor, &new_device_descriptor, sizeof(dev->descriptor)); + memcpy(&dev->descriptor, new_device_descriptor, sizeof(dev->descriptor)); err = usb_reset_configuration(dev); if (err < 0) dev_dbg(&dev->dev, "error usb_reset_configuration: %d\n", err); @@ -906,7 +910,7 @@ static void mbox2_setup_48_24_magic(struct usb_device *dev) static int snd_usb_mbox2_boot_quirk(struct usb_device *dev) { struct usb_host_config *config = dev->actconfig; - struct usb_device_descriptor new_device_descriptor; + struct usb_device_descriptor *new_device_descriptor __free(kfree) = NULL; int err; u8 bootresponse[0x12]; int fwsize; @@ -941,15 +945,19 @@ static int snd_usb_mbox2_boot_quirk(struct usb_device *dev)

dev_dbg(&dev->dev, "device initialised!\n");

+ new_device_descriptor = kmalloc(sizeof(*new_device_descriptor), GFP_KERNEL); + if (!new_device_descriptor) + return -ENOMEM; + err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, - &new_device_descriptor, sizeof(new_device_descriptor)); + new_device_descriptor, sizeof(*new_device_descriptor)); if (err < 0) dev_dbg(&dev->dev, "error usb_get_descriptor: %d\n", err); - if (new_device_descriptor.bNumConfigurations > dev->descriptor.bNumConfigurations) + if (new_device_descriptor->bNumConfigurations > dev->descriptor.bNumConfigurations) dev_dbg(&dev->dev, "error too large bNumConfigurations: %d\n", - new_device_descriptor.bNumConfigurations); + new_device_descriptor->bNumConfigurations); else - memcpy(&dev->descriptor, &new_device_descriptor, sizeof(dev->descriptor)); + memcpy(&dev->descriptor, new_device_descriptor, sizeof(dev->descriptor));

err = usb_reset_configuration(dev); if (err < 0) @@ -1259,7 +1267,7 @@ static void mbox3_setup_defaults(struct usb_device *dev) static int snd_usb_mbox3_boot_quirk(struct usb_device *dev) { struct usb_host_config *config = dev->actconfig; - struct usb_device_descriptor new_device_descriptor; + struct usb_device_descriptor *new_device_descriptor __free(kfree) = NULL; int err; int descriptor_size;

@@ -1272,15 +1280,19 @@ static int snd_usb_mbox3_boot_quirk(struct usb_device *dev)

dev_dbg(&dev->dev, "MBOX3: device initialised!\n");

+ new_device_descriptor = kmalloc(sizeof(*new_device_descriptor), GFP_KERNEL); + if (!new_device_descriptor) + return -ENOMEM; + err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, - &new_device_descriptor, sizeof(new_device_descriptor)); + new_device_descriptor, sizeof(*new_device_descriptor)); if (err < 0) dev_dbg(&dev->dev, "MBOX3: error usb_get_descriptor: %d\n", err); - if (new_device_descriptor.bNumConfigurations > dev->descriptor.bNumConfigurations) + if (new_device_descriptor->bNumConfigurations > dev->descriptor.bNumConfigurations) dev_dbg(&dev->dev, "MBOX3: error too large bNumConfigurations: %d\n", - new_device_descriptor.bNumConfigurations); + new_device_descriptor->bNumConfigurations); else - memcpy(&dev->descriptor, &new_device_descriptor, sizeof(dev->descriptor)); + memcpy(&dev->descriptor, new_device_descriptor, sizeof(dev->descriptor));

err = usb_reset_configuration(dev); if (err < 0)