user/sven/linux.git/include/linux/usb.h, branch v4.14.328

USB: core: Add routines for endpoint checks in old drivers

2023-05-30T11:38:38Z

commit 13890626501ffda22b18213ddaf7930473da5792 upstream. Many of the older USB drivers in the Linux USB stack were written based simply on a vendor's device specification. They use the endpoint information in the spec and assume these endpoints will always be present, with the properties listed, in any device matching the given vendor and product IDs. While that may have been true back then, with spoofing and fuzzing it is not true any more. More and more we are finding that those old drivers need to perform at least a minimum of checking before they try to use any endpoint other than ep0. To make this checking as simple as possible, we now add a couple of utility routines to the USB core. usb_check_bulk_endpoints() and usb_check_int_endpoints() take an interface pointer together with a list of endpoint addresses (numbers and directions). They check that the interface's current alternate setting includes endpoints with those addresses and that each of these endpoints has the right type: bulk or interrupt, respectively. Although we already have usb_find_common_endpoints() and related routines meant for a similar purpose, they are not well suited for this kind of checking. Those routines find endpoints of various kinds, but only one (either the first or the last) of each kind, and they don't verify that the endpoints' addresses agree with what the caller expects. In theory the new routines could be more general: They could take a particular altsetting as their argument instead of always using the interface's current altsetting. In practice I think this won't matter too much; multiple altsettings tend to be used for transferring media (audio or visual) over isochronous endpoints, not bulk or interrupt. Drivers for such devices will generally require more sophisticated checking than these simplistic routines provide. Signed-off-by: Alan Stern Link: https://lore.kernel.org/r/dd2c8e8c-2c87-44ea-ba17-c64b97e201c9@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

USB: core: Prevent nested device-reset calls

2022-09-15T10:23:51Z

commit 9c6d778800b921bde3bff3cff5003d1650f942d1 upstream. Automatic kernel fuzzing revealed a recursive locking violation in usb-storage: ============================================ WARNING: possible recursive locking detected 5.18.0 #3 Not tainted -------------------------------------------- kworker/1:3/1205 is trying to acquire lock: ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at: usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 but task is already holding lock: ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at: usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 ... stack backtrace: CPU: 1 PID: 1205 Comm: kworker/1:3 Not tainted 5.18.0 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain kernel/locking/lockdep.c:3816 [inline] __lock_acquire.cold+0x152/0x3ca kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5630 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x14f/0x1610 kernel/locking/mutex.c:747 usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 usb_reset_device+0x37d/0x9a0 drivers/usb/core/hub.c:6109 r871xu_dev_remove+0x21a/0x270 drivers/staging/rtl8712/usb_intf.c:622 usb_unbind_interface+0x1bd/0x890 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:545 [inline] device_remove+0x11f/0x170 drivers/base/dd.c:537 __device_release_driver drivers/base/dd.c:1222 [inline] device_release_driver_internal+0x1a7/0x2f0 drivers/base/dd.c:1248 usb_driver_release_interface+0x102/0x180 drivers/usb/core/driver.c:627 usb_forced_unbind_intf+0x4d/0xa0 drivers/usb/core/driver.c:1118 usb_reset_device+0x39b/0x9a0 drivers/usb/core/hub.c:6114 This turned out not to be an error in usb-storage but rather a nested device reset attempt. That is, as the rtl8712 driver was being unbound from a composite device in preparation for an unrelated USB reset (that driver does not have pre_reset or post_reset callbacks), its ->remove routine called usb_reset_device() -- thus nesting one reset call within another. Performing a reset as part of disconnect processing is a questionable practice at best. However, the bug report points out that the USB core does not have any protection against nested resets. Adding a reset_in_progress flag and testing it will prevent such errors in the future. Link: https://lore.kernel.org/all/CAB7eexKUpvX-JNiLzhXBDWgfg2T9e9_0Tw4HQ6keN==voRbP0g@mail.gmail.com/ Cc: stable@vger.kernel.org Reported-and-tested-by: Rondreis Signed-off-by: Alan Stern Link: https://lore.kernel.org/r/YwkflDxvg0KWqyZK@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

USB: core: Fix bug caused by duplicate interface PM usage counter

2019-05-08T05:20:46Z

commit c2b71462d294cf517a0bc6e4fd6424d7cee5596f upstream. The syzkaller fuzzer reported a bug in the USB hub driver which turned out to be caused by a negative runtime-PM usage counter. This allowed a hub to be runtime suspended at a time when the driver did not expect it. The symptom is a WARNING issued because the hub's status URB is submitted while it is already active: URB 0000000031fb463e submitted while active WARNING: CPU: 0 PID: 2917 at drivers/usb/core/urb.c:363 The negative runtime-PM usage count was caused by an unfortunate design decision made when runtime PM was first implemented for USB. At that time, USB class drivers were allowed to unbind from their interfaces without balancing the usage counter (i.e., leaving it with a positive count). The core code would take care of setting the counter back to 0 before allowing another driver to bind to the interface. Later on when runtime PM was implemented for the entire kernel, the opposite decision was made: Drivers were required to balance their runtime-PM get and put calls. In order to maintain backward compatibility, however, the USB subsystem adapted to the new implementation by keeping an independent usage counter for each interface and using it to automatically adjust the normal usage counter back to 0 whenever a driver was unbound. This approach involves duplicating information, but what is worse, it doesn't work properly in cases where a USB class driver delays decrementing the usage counter until after the driver's disconnect() routine has returned and the counter has been adjusted back to 0. Doing so would cause the usage counter to become negative. There's even a warning about this in the USB power management documentation! As it happens, this is exactly what the hub driver does. The kick_hub_wq() routine increments the runtime-PM usage counter, and the corresponding decrement is carried out by hub_event() in the context of the hub_wq work-queue thread. This work routine may sometimes run after the driver has been unbound from its interface, and when it does it causes the usage counter to go negative. It is not possible for hub_disconnect() to wait for a pending hub_event() call to finish, because hub_disconnect() is called with the device lock held and hub_event() acquires that lock. The only feasible fix is to reverse the original design decision: remove the duplicate interface-specific usage counter and require USB drivers to balance their runtime PM gets and puts. As far as I know, all existing drivers currently do this. Signed-off-by: Alan Stern Reported-and-tested-by: syzbot+7634edaea4d0b341c625@syzkaller.appspotmail.com CC: Signed-off-by: Greg Kroah-Hartman

USB: check usb_get_extra_descriptor for proper size

2018-12-13T08:18:51Z

commit 704620afc70cf47abb9d6a1a57f3825d2bca49cf upstream. When reading an extra descriptor, we need to properly check the minimum and maximum size allowed, to prevent from invalid data being sent by a device. Reported-by: Hui Peng Reported-by: Mathias Payer Co-developed-by: Linus Torvalds Signed-off-by: Hui Peng Signed-off-by: Mathias Payer Signed-off-by: Linus Torvalds Cc: stable Signed-off-by: Greg Kroah-Hartman

usb: core: Add a helper function to check the validity of EP type in URB

2018-02-25T10:07:45Z

commit e901b9873876ca30a09253731bd3a6b00c44b5b0 upstream. This patch adds a new helper function to perform a sanity check of the given URB to see whether it contains a valid endpoint. It's a light- weight version of what usb_submit_urb() does, but without the kernel warning followed by the stack trace, just returns an error code. Especially for a driver that doesn't parse the descriptor but fills the URB with the fixed endpoint (e.g. some quirks for non-compliant devices), this kind of check is preferable at the probe phase before actually submitting the urb. Tested-by: Andrey Konovalov Acked-by: Greg Kroah-Hartman Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

usb: fix some references for /proc/bus/usb

2017-04-18T14:54:19Z

Since when we got rid of usbfs, the /proc/bus/usb is now elsewhere. Fix references for it. Signed-off-by: Mauro Carvalho Chehab Acked-by: Serge Hallyn Signed-off-by: Greg Kroah-Hartman

USB: core: add helpers to retrieve endpoints in reverse order

2017-03-23T12:53:16Z

Several drivers have implemented their endpoint look-up loops in such a way that they have picked the last endpoint descriptor of the specified type should more than one such descriptor exist. To avoid any regressions, add corresponding helpers to lookup endpoints by searching the endpoint descriptors in reverse order. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman

USB: core: add helpers to retrieve endpoints

2017-03-23T12:53:16Z

Many USB drivers iterate over the available endpoints to find required endpoints of a specific type and direction. Typically the endpoints are required for proper function and a missing endpoint should abort probe. To facilitate code reuse, add a helper to retrieve common endpoints (bulk or interrupt, in or out) and four wrappers to find a single endpoint. Note that the helpers are marked as __must_check to serve as a reminder to always verify that all expected endpoints are indeed present. This also means that any optional endpoints, typically need to be looked up through separate calls. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman

usb: separate out sysdev pointer from usb_bus

2017-03-23T07:20:21Z

For xhci-hcd platform device, all the DMA parameters are not configured properly, notably dma ops for dwc3 devices. The idea here is that you pass in the parent of_node along with the child device pointer, so it would behave exactly like the parent already does. The difference is that it also handles all the other attributes besides the mask. sysdev will represent the physical device, as seen from firmware or bus.Splitting the usb_bus->controller field into the Linux-internal device (used for the sysfs hierarchy, for printks and for power management) and a new pointer (used for DMA, DT enumeration and phy lookup) probably covers all that we really need. Signed-off-by: Arnd Bergmann Signed-off-by: Sriram Dash Tested-by: Baolin Wang Tested-by: Brian Norris Tested-by: Alexander Sverdlin Tested-by: Vivek Gautam Signed-off-by: Mathias Nyman Signed-off-by: Peter Chen Cc: Felipe Balbi Cc: Grygorii Strashko Cc: Sinjan Kumar Cc: David Fisher Cc: Catalin Marinas Cc: "Thang Q. Nguyen" Cc: Yoshihiro Shimoda Cc: Stephen Boyd Cc: Bjorn Andersson Cc: Ming Lei Cc: Jon Masters Cc: Dann Frazier Cc: Peter Chen Cc: Leo Li Signed-off-by: Greg Kroah-Hartman