5.4-stable review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter dan.carpenter@linaro.org
commit f7d306b47a24367302bd4fe846854e07752ffcd9 upstream.
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 Signed-off-by: Benoît Sevens bsevens@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- sound/usb/quirks.c | 31 +++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 10 deletions(-)
--- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -585,7 +585,7 @@ int snd_usb_create_quirk(struct snd_usb_ 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 = NULL; int err;
if (le16_to_cpu(get_cfg_desc(config)->wTotalLength) == EXTIGY_FIRMWARE_SIZE_OLD || @@ -596,15 +596,20 @@ static int snd_usb_extigy_boot_quirk(str 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)); + kfree(new_device_descriptor); err = usb_reset_configuration(dev); if (err < 0) dev_dbg(&dev->dev, "error usb_reset_configuration: %d\n", err); @@ -938,7 +943,7 @@ static void mbox2_setup_48_24_magic(stru 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 = NULL; int err; u8 bootresponse[0x12]; int fwsize; @@ -973,15 +978,21 @@ static int snd_usb_mbox2_boot_quirk(stru
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)); + + kfree(new_device_descriptor);
err = usb_reset_configuration(dev); if (err < 0)