From 464ad8c43a9ead98c2b0eaed86bea727f2ad106e Mon Sep 17 00:00:00 2001 From: Hans Yang Date: Tue, 1 Dec 2015 16:54:59 +0800 Subject: usb: core : hub: Fix BOS 'NULL pointer' kernel panic When a USB 3.0 mass storage device is disconnected in transporting state, storage device driver may handle it as a transport error and reset the device by invoking usb_reset_and_verify_device() and following could happen: in usb_reset_and_verify_device(): udev->bos = NULL; For U1/U2 enabled devices, driver will disable LPM, and in some conditions: from usb_unlocked_disable_lpm() --> usb_disable_lpm() --> usb_enable_lpm() udev->bos->ss_cap->bU1devExitLat; And it causes 'NULL pointer' and 'kernel panic': [ 157.976257] Unable to handle kernel NULL pointer dereference at virtual address 00000010 ... [ 158.026400] PC is at usb_enable_link_state+0x34/0x2e0 [ 158.031442] LR is at usb_enable_lpm+0x98/0xac ... [ 158.137368] [] usb_enable_link_state+0x34/0x2e0 [ 158.143451] [] usb_enable_lpm+0x94/0xac [ 158.148840] [] usb_disable_lpm+0xa8/0xb4 ... [ 158.214954] Kernel panic - not syncing: Fatal exception This commit moves 'udev->bos = NULL' behind usb_unlocked_disable_lpm() to prevent from NULL pointer access. Issue can be reproduced by following setup: 1) A SS pen drive behind a SS hub connected to the host. 2) Transporting data between the pen drive and the host. 3) Abruptly disconnect hub and pen drive from host. 4) With a chance it crashes. Signed-off-by: Hans Yang Acked-by: Alan Stern Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) (limited to 'drivers/usb/core/hub.c') diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index bdeadc112d29..585c3cb07da6 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -5326,9 +5326,6 @@ static int usb_reset_and_verify_device(struct usb_device *udev) if (udev->usb2_hw_lpm_enabled == 1) usb_set_usb2_hardware_lpm(udev, 0); - bos = udev->bos; - udev->bos = NULL; - /* Disable LPM and LTM while we reset the device and reinstall the alt * settings. Device-initiated LPM settings, and system exit latency * settings are cleared when the device is reset, so we have to set @@ -5337,15 +5334,18 @@ static int usb_reset_and_verify_device(struct usb_device *udev) ret = usb_unlocked_disable_lpm(udev); if (ret) { dev_err(&udev->dev, "%s Failed to disable LPM\n.", __func__); - goto re_enumerate; + goto re_enumerate_no_bos; } ret = usb_disable_ltm(udev); if (ret) { dev_err(&udev->dev, "%s Failed to disable LTM\n.", __func__); - goto re_enumerate; + goto re_enumerate_no_bos; } + bos = udev->bos; + udev->bos = NULL; + for (i = 0; i < SET_CONFIG_TRIES; ++i) { /* ep0 maxpacket size may change; let the HCD know about it. @@ -5442,10 +5442,11 @@ done: return 0; re_enumerate: - /* LPM state doesn't matter when we're about to destroy the device. */ - hub_port_logical_disconnect(parent_hub, port1); usb_release_bos_descriptor(udev); udev->bos = bos; +re_enumerate_no_bos: + /* LPM state doesn't matter when we're about to destroy the device. */ + hub_port_logical_disconnect(parent_hub, port1); return -ENODEV; } -- cgit v1.2.3 From ad87e03213b552a5c33d5e1e7a19a73768397010 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Thu, 10 Dec 2015 15:27:21 -0500 Subject: USB: add quirk for devices with broken LPM Some USB device / host controller combinations seem to have problems with Link Power Management. For example, Steinar found that his xHCI controller wouldn't handle bandwidth calculations correctly for two video cards simultaneously when LPM was enabled, even though the bus had plenty of bandwidth available. This patch introduces a new quirk flag for devices that should remain disabled for LPM, and creates quirk entries for Steinar's devices. Signed-off-by: Alan Stern Reported-by: Steinar H. Gunderson Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 7 ++++++- drivers/usb/core/quirks.c | 6 ++++++ include/linux/usb/quirks.h | 3 +++ 3 files changed, 15 insertions(+), 1 deletion(-) (limited to 'drivers/usb/core/hub.c') diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 585c3cb07da6..a5cc032ef77a 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -124,6 +124,10 @@ struct usb_hub *usb_hub_to_struct_hub(struct usb_device *hdev) int usb_device_supports_lpm(struct usb_device *udev) { + /* Some devices have trouble with LPM */ + if (udev->quirks & USB_QUIRK_NO_LPM) + return 0; + /* USB 2.1 (and greater) devices indicate LPM support through * their USB 2.0 Extended Capabilities BOS descriptor. */ @@ -4512,6 +4516,8 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1, goto fail; } + usb_detect_quirks(udev); + if (udev->wusb == 0 && le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0201) { retval = usb_get_bos_descriptor(udev); if (!retval) { @@ -4710,7 +4716,6 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus, if (status < 0) goto loop; - usb_detect_quirks(udev); if (udev->quirks & USB_QUIRK_DELAY_INIT) msleep(1000); diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c index fcd6ac0c667f..6dc810bce295 100644 --- a/drivers/usb/core/quirks.c +++ b/drivers/usb/core/quirks.c @@ -202,6 +202,12 @@ static const struct usb_device_id usb_quirk_list[] = { { USB_DEVICE(0x1a0a, 0x0200), .driver_info = USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL }, + /* Blackmagic Design Intensity Shuttle */ + { USB_DEVICE(0x1edb, 0xbd3b), .driver_info = USB_QUIRK_NO_LPM }, + + /* Blackmagic Design UltraStudio SDI */ + { USB_DEVICE(0x1edb, 0xbd4f), .driver_info = USB_QUIRK_NO_LPM }, + { } /* terminating entry must be last */ }; diff --git a/include/linux/usb/quirks.h b/include/linux/usb/quirks.h index 9948c874e3f1..1d0043dc34e4 100644 --- a/include/linux/usb/quirks.h +++ b/include/linux/usb/quirks.h @@ -47,4 +47,7 @@ /* device generates spurious wakeup, ignore remote wakeup capability */ #define USB_QUIRK_IGNORE_REMOTE_WAKEUP BIT(9) +/* device can't handle Link Power Management */ +#define USB_QUIRK_NO_LPM BIT(10) + #endif /* __LINUX_USB_QUIRKS_H */ -- cgit v1.2.3 From e50293ef9775c5f1cf3fcc093037dd6a8c5684ea Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 16 Dec 2015 13:32:38 -0500 Subject: USB: fix invalid memory access in hub_activate() Commit 8520f38099cc ("USB: change hub initialization sleeps to delayed_work") changed the hub_activate() routine to make part of it run in a workqueue. However, the commit failed to take a reference to the usb_hub structure or to lock the hub interface while doing so. As a result, if a hub is plugged in and quickly unplugged before the work routine can run, the routine will try to access memory that has been deallocated. Or, if the hub is unplugged while the routine is running, the memory may be deallocated while it is in active use. This patch fixes the problem by taking a reference to the usb_hub at the start of hub_activate() and releasing it at the end (when the work is finished), and by locking the hub interface while the work routine is running. It also adds a check at the start of the routine to see if the hub has already been disconnected, in which nothing should be done. Signed-off-by: Alan Stern Reported-by: Alexandru Cornea Tested-by: Alexandru Cornea Fixes: 8520f38099cc ("USB: change hub initialization sleeps to delayed_work") CC: Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) (limited to 'drivers/usb/core/hub.c') diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index a5cc032ef77a..ddbf32d599cb 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1035,10 +1035,20 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type) unsigned delay; /* Continue a partial initialization */ - if (type == HUB_INIT2) - goto init2; - if (type == HUB_INIT3) + if (type == HUB_INIT2 || type == HUB_INIT3) { + device_lock(hub->intfdev); + + /* Was the hub disconnected while we were waiting? */ + if (hub->disconnected) { + device_unlock(hub->intfdev); + kref_put(&hub->kref, hub_release); + return; + } + if (type == HUB_INIT2) + goto init2; goto init3; + } + kref_get(&hub->kref); /* The superspeed hub except for root hub has to use Hub Depth * value as an offset into the route string to locate the bits @@ -1236,6 +1246,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type) queue_delayed_work(system_power_efficient_wq, &hub->init_work, msecs_to_jiffies(delay)); + device_unlock(hub->intfdev); return; /* Continues at init3: below */ } else { msleep(delay); @@ -1257,6 +1268,11 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type) /* Allow autosuspend if it was suppressed */ if (type <= HUB_INIT3) usb_autopm_put_interface_async(to_usb_interface(hub->intfdev)); + + if (type == HUB_INIT2 || type == HUB_INIT3) + device_unlock(hub->intfdev); + + kref_put(&hub->kref, hub_release); } /* Implement the continuations for the delays above */ -- cgit v1.2.3