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Gustavo A. R. Silva authored
pdev_nr and rhport can be controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: drivers/usb/usbip/vhci_sysfs.c:238 detach_store() warn: potential spectre issue 'vhcis' drivers/usb/usbip/vhci_sysfs.c:328 attach_store() warn: potential spectre issue 'vhcis' drivers/usb/usbip/vhci_sysfs.c:338 attach_store() warn: potential spectre issue 'vhci->vhci_hcd_ss->vdev' drivers/usb/usbip/vhci_sysfs.c:340 attach_store() warn: potential spectre issue 'vhci->vhci_hcd_hs->vdev' Fix this by sanitizing pdev_nr and rhport before using them to index vhcis and vhci->vhci_hcd_ss->vdev respectively. Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Acked-by: Shuah Khan (Samsung OSG) <shuah@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CVE-2017-5753 (backported from commit a0d6ec88) [juergh: - Adjusted context. - Dropped the modification of valid_port() (not in Xenial) and modified the port checks in valid_args() and store_detach() instead().] Signed-off-by: Juerg Haefliger <juergh@canonical.com> Acked-by: Stefan Bader <stefan.bader@canonical.com> Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
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