| From | Ben Hutchings <> | Date | Fri, 10 Mar 2017 11:46:22 +0000 | Subject | [PATCH 3.16 140/370] usb: gadgetfs: restrict upper bound on device configuration size |
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3.16.42-rc1 review patch. If anyone has any objections, please let me know.
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0994b0a257557e18ee8f0b7c5f0f73fe2b54eec1 upstream.
Andrey Konovalov reported that we were not properly checking the upper limit before of a device configuration size before calling memdup_user(), which could cause some problems.
So set the upper limit to PAGE_SIZE * 4, which should be good enough for all devices.
Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- drivers/usb/gadget/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/usb/gadget/inode.c +++ b/drivers/usb/gadget/inode.c @@ -1862,7 +1862,8 @@ dev_config (struct file *fd, const char u32 tag; char *kbuf; - if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) + if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) || + (len > PAGE_SIZE * 4)) return -EINVAL; /* we might need to change message format someday */
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