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-rw-r--r--libre/linux-libre/0004-xhci-Fix-USB3-NULL-pointer-dereference-at-logical-di.patch63
1 files changed, 63 insertions, 0 deletions
diff --git a/libre/linux-libre/0004-xhci-Fix-USB3-NULL-pointer-dereference-at-logical-di.patch b/libre/linux-libre/0004-xhci-Fix-USB3-NULL-pointer-dereference-at-logical-di.patch
new file mode 100644
index 000000000..009251cb3
--- /dev/null
+++ b/libre/linux-libre/0004-xhci-Fix-USB3-NULL-pointer-dereference-at-logical-di.patch
@@ -0,0 +1,63 @@
+From 005c2f4576d9bab5ff97dac4b3d27aafa2f1f153 Mon Sep 17 00:00:00 2001
+Message-Id: <005c2f4576d9bab5ff97dac4b3d27aafa2f1f153.1526520264.git.jan.steffens@gmail.com>
+In-Reply-To: <1d8e17daf031e219d904ef93718081534c9e8cea.1526520263.git.jan.steffens@gmail.com>
+References: <1d8e17daf031e219d904ef93718081534c9e8cea.1526520263.git.jan.steffens@gmail.com>
+From: Mathias Nyman <mathias.nyman@linux.intel.com>
+Date: Mon, 14 May 2018 11:57:23 +0300
+Subject: [PATCH 4/4] xhci: Fix USB3 NULL pointer dereference at logical
+ disconnect.
+
+Hub driver will try to disable a USB3 device twice at logical disconnect,
+racing with xhci_free_dev() callback from the first port disable.
+
+This can be triggered with "udisksctl power-off --block-device <disk>"
+or by writing "1" to the "remove" sysfs file for a USB3 device
+in 4.17-rc4.
+
+USB3 devices don't have a similar disabled link state as USB2 devices,
+and use a U3 suspended link state instead. In this state the port
+is still enabled and connected.
+
+hub_port_connect() first disconnects the device, then later it notices
+that device is still enabled (due to U3 states) it will try to disable
+the port again (set to U3).
+
+The xhci_free_dev() called during device disable is async, so checking
+for existing xhci->devs[i] when setting link state to U3 the second time
+was successful, even if device was being freed.
+
+The regression was caused by, and whole thing revealed by,
+Commit 44a182b9d177 ("xhci: Fix use-after-free in xhci_free_virt_device")
+which sets xhci->devs[i]->udev to NULL before xhci_virt_dev() returned.
+and causes a NULL pointer dereference the second time we try to set U3.
+
+Fix this by checking xhci->devs[i]->udev exists before setting link state.
+
+The original patch went to stable so this fix needs to be applied there as
+well.
+
+Fixes: 44a182b9d177 ("xhci: Fix use-after-free in xhci_free_virt_device")
+Cc: <stable@vger.kernel.org>
+Reported-by: Jordan Glover <Golden_Miller83@protonmail.ch>
+Tested-by: Jordan Glover <Golden_Miller83@protonmail.ch>
+Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
+---
+ drivers/usb/host/xhci-hub.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
+index 72ebbc908e19..32cd52ca8318 100644
+--- a/drivers/usb/host/xhci-hub.c
++++ b/drivers/usb/host/xhci-hub.c
+@@ -354,7 +354,7 @@ int xhci_find_slot_id_by_port(struct usb_hcd *hcd, struct xhci_hcd *xhci,
+
+ slot_id = 0;
+ for (i = 0; i < MAX_HC_SLOTS; i++) {
+- if (!xhci->devs[i])
++ if (!xhci->devs[i] || !xhci->devs[i]->udev)
+ continue;
+ speed = xhci->devs[i]->udev->speed;
+ if (((speed >= USB_SPEED_SUPER) == (hcd->speed >= HCD_USB3))
+--
+2.17.0
+