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| author | Gerd Hoffmann <kraxel@redhat.com> | 2021-05-03 15:29:15 +0200 |
|---|---|---|
| committer | Michael Roth <michael.roth@amd.com> | 2021-10-17 20:20:04 -0500 |
| commit | e204dca909ed2fe5aa18f03c973e3ad6cff98595 (patch) | |
| tree | c884796b00748ff1e870f9af11ec00dcd7b3e321 | |
| parent | 606f618b3c1d517edaf145cd8648a9b5ae3fc941 (diff) | |
| download | qemu-e204dca909ed2fe5aa18f03c973e3ad6cff98595.zip qemu-e204dca909ed2fe5aa18f03c973e3ad6cff98595.tar.gz qemu-e204dca909ed2fe5aa18f03c973e3ad6cff98595.tar.bz2 | |
usb: limit combined packets to 1 MiB (CVE-2021-3527)
usb-host and usb-redirect try to batch bulk transfers by combining many
small usb packets into a single, large transfer request, to reduce the
overhead and improve performance.
This patch adds a size limit of 1 MiB for those combined packets to
restrict the host resources the guest can bind that way.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20210503132915.2335822-6-kraxel@redhat.com>
(cherry picked from commit 05a40b172e4d691371534828078be47e7fff524c)
Signed-off-by: Michael Roth <michael.roth@amd.com>
| -rw-r--r-- | hw/usb/combined-packet.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/hw/usb/combined-packet.c b/hw/usb/combined-packet.c index 5d57e88..e56802f 100644 --- a/hw/usb/combined-packet.c +++ b/hw/usb/combined-packet.c @@ -171,7 +171,9 @@ void usb_ep_combine_input_packets(USBEndpoint *ep) if ((p->iov.size % ep->max_packet_size) != 0 || !p->short_not_ok || next == NULL || /* Work around for Linux usbfs bulk splitting + migration */ - (totalsize == (16 * KiB - 36) && p->int_req)) { + (totalsize == (16 * KiB - 36) && p->int_req) || + /* Next package may grow combined package over 1MiB */ + totalsize > 1 * MiB - ep->max_packet_size) { usb_device_handle_data(ep->dev, first); assert(first->status == USB_RET_ASYNC); if (first->combined) { |