kernel/linux.git/drivers/usb/core/urb.c, branch linux-7.0.y

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

usb: core: support eUSB2 double bandwidth large isoc URB frames

2025-09-06T13:25:05+00:00

eUSB2 double isochronous in bandwidth devices support up to 6 transactions per microframe, and thus doubles the total bytes possible to receive per microframe. Support larger URB isoc frame sizes for eUSB2 double isoc in endpoints. Also usb_endpoint_maxp() returns a natural number so there's no need to assume it could be < 0. Signed-off-by: Rai, Amardeep Reviewed-by: Sakari Ailus Signed-off-by: Mathias Nyman Co-developed-by: Sakari Ailus Signed-off-by: Sakari Ailus Acked-by: Alan Stern Acked-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20250820143824.551777-9-sakari.ailus@linux.intel.com

usb: core: usb_submit_urb: downgrade type check

2025-06-19T10:27:43+00:00

Checking for the endpoint type is no reason for a WARN, as that can cause a reboot. A driver not checking the endpoint type must not cause a reboot, as there is just no point in this. We cannot prevent a device from doing something incorrect as a reaction to a transfer. Hence warning for a mere assumption being wrong is not sensible. Signed-off-by: Oliver Neukum Acked-by: Alan Stern Link: https://lore.kernel.org/r/20250612122149.2559724-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman

usb: core: Remove unused usb_unlink_anchored_urbs

2025-06-19T10:27:02+00:00

usb_unlink_anchored_urbs() has been unused since it's last use was removed in 2009 by commit 9b9c5aaeedfd ("ar9170: xmit code revamp") Remove it. Signed-off-by: "Dr. David Alan Gilbert" Acked-by: Randy Dunlap Link: https://lore.kernel.org/r/20250608235617.200731-1-linux@treblig.org Signed-off-by: Greg Kroah-Hartman

usb: core: Don't use %pK through printk

2025-03-14T08:17:29+00:00

This is a revert of commit 2f964780c03b ("USB: core: replace %p with %pK"). When the formatting was changed from %p to %pK that was a security improvement, as %p would leak raw pointer values to the kernel log. Since commit ad67b74d2469 ("printk: hash addresses printed with %p") the regular %p has been improved to avoid this issue. On the other hand, restricted pointers ("%pK") were never meant to be used through printk(). They can unintentionally still leak raw pointers or acquire sleeping looks in atomic contexts. Switch back to regular %p again. Link: https://lore.kernel.org/lkml/20250113171731-dc10e3c1-da64-4af0-b767-7c7070468023@linutronix.de/ Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20250310-restricted-pointers-usb-v2-1-a7598e2d47d1@linutronix.de Signed-off-by: Greg Kroah-Hartman

USB: Remove remnants of Wireless USB and UWB

2023-08-09T12:17:06+00:00

Wireless USB has long been defunct, and kernel support for it was removed in 2020 by commit caa6772db4c1 ("Staging: remove wusbcore and UWB from the kernel tree."). Nevertheless, some vestiges of the old implementation still clutter up the USB subsystem and one or two other places. Let's get rid of them once and for all. The only parts still left are the user-facing APIs in include/uapi/linux/usb/ch9.h. (There are also a couple of misleading instances, such as the Sierra Wireless USB modem, which is a USB modem made by Sierra Wireless.) Signed-off-by: Alan Stern Link: https://lore.kernel.org/r/b4f2710f-a2de-4fb0-b50f-76776f3a961b@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

kmsan: handle memory sent to/from USB

2022-10-03T21:03:22+00:00

Depending on the value of is_out kmsan_handle_urb() KMSAN either marks the data copied to the kernel from a USB device as initialized, or checks the data sent to the device for being initialized. Link: https://lkml.kernel.org/r/20220915150417.722975-24-glider@google.com Signed-off-by: Alexander Potapenko Cc: Alexander Viro Cc: Alexei Starovoitov Cc: Andrey Konovalov Cc: Andrey Konovalov Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Christoph Hellwig Cc: Christoph Lameter Cc: David Rientjes Cc: Dmitry Vyukov Cc: Eric Biggers Cc: Eric Biggers Cc: Eric Dumazet Cc: Greg Kroah-Hartman Cc: Herbert Xu Cc: Ilya Leoshkevich Cc: Ingo Molnar Cc: Jens Axboe Cc: Joonsoo Kim Cc: Kees Cook Cc: Marco Elver Cc: Mark Rutland Cc: Matthew Wilcox Cc: Michael S. Tsirkin Cc: Pekka Enberg Cc: Peter Zijlstra Cc: Petr Mladek Cc: Stephen Rothwell Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vegard Nossum Cc: Vlastimil Babka Signed-off-by: Andrew Morton

USB: core: Fix hang in usb_kill_urb by adding memory barriers

2022-01-25T17:43:19+00:00

The syzbot fuzzer has identified a bug in which processes hang waiting for usb_kill_urb() to return. It turns out the issue is not unlinking the URB; that works just fine. Rather, the problem arises when the wakeup notification that the URB has completed is not received. The reason is memory-access ordering on SMP systems. In outline form, usb_kill_urb() and __usb_hcd_giveback_urb() operating concurrently on different CPUs perform the following actions: CPU 0 CPU 1 ---------------------------- --------------------------------- usb_kill_urb(): __usb_hcd_giveback_urb(): ... ... atomic_inc(&urb->reject); atomic_dec(&urb->use_count); ... ... wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); if (atomic_read(&urb->reject)) wake_up(&usb_kill_urb_queue); Confining your attention to urb->reject and urb->use_count, you can see that the overall pattern of accesses on CPU 0 is: write urb->reject, then read urb->use_count; whereas the overall pattern of accesses on CPU 1 is: write urb->use_count, then read urb->reject. This pattern is referred to in memory-model circles as SB (for "Store Buffering"), and it is well known that without suitable enforcement of the desired order of accesses -- in the form of memory barriers -- it is entirely possible for one or both CPUs to execute their reads ahead of their writes. The end result will be that sometimes CPU 0 sees the old un-decremented value of urb->use_count while CPU 1 sees the old un-incremented value of urb->reject. Consequently CPU 0 ends up on the wait queue and never gets woken up, leading to the observed hang in usb_kill_urb(). The same pattern of accesses occurs in usb_poison_urb() and the failure pathway of usb_hcd_submit_urb(). The problem is fixed by adding suitable memory barriers. To provide proper memory-access ordering in the SB pattern, a full barrier is required on both CPUs. The atomic_inc() and atomic_dec() accesses themselves don't provide any memory ordering, but since they are present, we can use the optimized smp_mb__after_atomic() memory barrier in the various routines to obtain the desired effect. This patch adds the necessary memory barriers. CC: Reported-and-tested-by: syzbot+76629376e06e2c2ad626@syzkaller.appspotmail.com Signed-off-by: Alan Stern Link: https://lore.kernel.org/r/Ye8K0QYee0Q0Nna2@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

USB: core: Check buffer length matches wLength for control transfers

2021-05-27T11:46:21+00:00

A type of inconsistency that can show up in control URBs is when the setup packet's wLength value does not match the URB's transfer_buffer_length field. The two should always be equal; differences could lead to information leaks or undefined behavior for OUT transfers or overruns for IN transfers. This patch adds a test for such mismatches during URB submission. If the test fails, the submission is rejected with a -EBADR error code (which is not used elsewhere in the USB core), and a debugging message is logged for people interested in tracking down these errors. Reviewed-by: Johan Hovold Signed-off-by: Alan Stern Link: https://lore.kernel.org/r/20210526153244.GA1400430@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

USB: core: WARN if pipe direction != setup packet direction

2021-05-22T08:37:25+00:00

When a control URB is submitted, the direction indicated by URB's pipe member is supposed to match the direction indicated by the setup packet's bRequestType member. A mismatch could lead to trouble, depending on which field the host controller drivers use for determining the actual direction. This shouldn't ever happen; it would represent a careless bug in a kernel driver somewhere. This patch adds a dev_WARN_ONCE to let people know about the potential problem. Suggested-by: "Geoffrey D. Bennett" Reviewed-by: Johan Hovold Signed-off-by: Alan Stern Link: https://lore.kernel.org/r/20210522021623.GB1260282@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman