kernel/git/next/linux-next.git/drivers/usb/host, branch master

xhci: fix lost bounce buffers on TDs spanning several ring segments

2026-08-31T09:43:00+00:00

When a TD reaches a link TRB with data that is not aligned to the endpoint's wMaxPacketSize, xhci_align_td() stages the unalignable tail through the bounce buffer of the ring segment holding that link TRB. xhci_unmap_td_bounce_buffer() later unmaps it and, for IN transfers, copies the data back into the URB's buffer. The enqueue path records the segment that was bounced in td->bounce_seg, under the assumption that a TD never spans more than two ring segments. That assumption does not hold: a TD large enough to span three or more segments crosses several link TRBs and can be bounced at each of them. Only the last one survives in td->bounce_seg, so every earlier bounce buffer is neither copied back nor DMA unmapped. The URB still completes with actual_length equal to the requested length and no error, so the transfer looks successful while a wMaxPacketSize sized hole in the destination buffer silently keeps its previous contents. It also leaks a DMA mapping per dropped bounce. Any sufficiently large and fragmented bulk transfer can hit this. It was found with a USB mass storage device behind xHCI backing a dm-verity target with 512 byte hash blocks, where the stale data is detected rather than silently consumed. The device enumerates as SuperSpeed, so wMaxPacketSize is 1024, while dm-bufio issues one 512 byte bio per hash block. verity_prefetch_io() makes the block layer merge hundreds of them into a single request of up to 512 scatterlist entries of 512 bytes each. At 256 TRBs per ring segment such a TD spans three segments, and every segment boundary falls on an odd multiple of 512, i.e. unaligned to wMaxPacketSize. dm-bufio then caches a hash block holding stale data and dm-verity declares the metadata block corrupted: device-mapper: verity: 8:2: metadata block 10850 is corrupted A reproducer running this under qemu is available at https://github.com/baloo/xhci-verity The bounce state (bounce_buf, bounce_dma, bounce_len, bounce_offs) already lives on the ring segment, so there is nothing extra to track. Keep recording the last bounced segment in td->bounce_seg and, on completion, walk the segments from td->start_seg up to it, unmapping every segment that still has a pending bounce. Stopping at td->bounce_seg rather than td->end_seg matters: a bounce implies the TD continues past that segment's link TRB, so bounce_seg is always strictly before end_seg, and a later TD may already have started in end_seg and been bounced there. Walking that far would copy a foreign bounce buffer into this URB and unmap it twice. It also keeps the walk correct if a TD ever wraps the whole ring so that end_seg == start_seg. [mn: Add ring->num_segs check to prevent unlikely infinite for loop.] Fixes: f9c589e142d0 ("xhci: TD-fragment, align the unsplittable case with a bounce buffer") Cc: stable@vger.kernel.org Suggested-by: Michal Pecio Signed-off-by: Arthur Gautier Signed-off-by: Mathias Nyman Link: https://patch.msgid.link/20260831090448.95644-4-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: xhci: Fix isochronous scheduling regression

2026-08-31T09:43:00+00:00

An isoc URB without URB_ISO_ASAP should be scheduled immediately after the previous one, unless it's the first submission or prior URBs have completed without resubmitting and the endpoint became idle. An HCD_BH driver must consider URBs pending completion in the BH queue in addition to its own queue. Regrettably, core doesn't provide much information, we can only know if we are being called by completion now. This issue is as old as HCD_BH, affects ehci-hcd too and has no known reproducible impact, as drivers generally resubmit from completion. A recent patch tried to address it by looking at xHCI HW state instead. Obviously, HW has no knowledge of the BH giveback queue either, and the whole solution amounts to testing whether prior URBs have been unlinked instead of completing normally - then a new stream is assumed. This leads to false negatives when a driver simply allows the endpoint to empty out and begins a new stream. New URBs are scheduled into the past and promptly fail with -EXDEV status, causing data loss and worse, because drivers get confused by premature completion, particularly when multiple endpoints are started at once and required to stay in sync. snd-usb-audio underruns the OUT endpoint when userspace fails to supply playback data in time. If this is detected in duplex mode, IN URBs are unlinked and both streams restarted. OUT underruns again before IN even begins, another recovery is attempted and the cycle repeats. Fix this by using the best criteria we can muster, taken from ehci-hcd. This brings false negative rate back to zero and false positive rate to less than ever before in xhci-hcd. Traditional logic was equivalent to: if (list_empty(&ep_ring->td_list) || GET_EP_CTX_STATE(ep_ctx) != EP_STATE_RUNNING) // consider this URB a new stream While free of false negatives, it had easily avoidable false positives: * no check for completion in progress when the list is empty * the ep_ctx check doesn't make up for it at all, but it adds a race - EP state can remain "stopped" for a while after the first submission [mn: add debug message in possible false positive case where driver might incorrectly assume new stream starts mid stream just because td list is empty (URB enqueue is late), and workqueue isn't processing URB completions for this endpoint at the moment] Link: https://lore.kernel.org/linux-usb/20260813005635.34750f8c.michal.pecio@gmail.com/ Fixes: add8469b3e00 ("xhci: fix frame id calculation and checks for isoc URBs") Signed-off-by: Michal Pecio Signed-off-by: Mathias Nyman Link: https://patch.msgid.link/20260831090448.95644-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: xhci: Fix HCS_ERST_MAX conversion

2026-08-31T09:43:00+00:00

This fixes one broken line in commit 6d45e9556d4a ("usb: xhci: standardize multi bit-field macros") included in 7.3-rc1 kernel HCS_ERST_MAX holds power of 2 value for maximum number of segments. In the culprit commit, this was incorrectly converted to "shift up 2". On hardware where this field is zero, this results in xhci_alloc_erst() calling dma_alloc_coherent() with size = 0, leading to a horrible splat and non-usable XHCI. Revert the shift-up-2 to the BIT() macro. Fixes: 6d45e9556d4a ("usb: xhci: standardize multi bit-field macros") Cc: Niklas Neronin Signed-off-by: Chen-Yu Tsai Signed-off-by: Mathias Nyman Tested-by: Pierre-David Belanger Link: https://patch.msgid.link/20260831090448.95644-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

Merge tag 'usb-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

2026-08-25T17:44:46+00:00

Pull USB / Thunderbolt updates from Greg KH: "Here is the big set of USB and Thunderbolt driver updates for 7.3-rc1. Lots of driver work for new devices and systems, and many other minor fixes and updates. Included in here are: - Thunderbolt subsystem driver updates and additions - typec driver updates and additions - usb gadget fixes all over the place, seems like people are finally paying attention to these drivers for some reason - xhci driver updates and fixes based on lots of reports - usb-serial driver updates and additions - new device ids - other minor USB driver updates and fixes All of these have been in linux-next for a while with no reported issues" * tag 'usb-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (163 commits) usb: gadget: uvc: fix dangling pointers in uvc_function_bind() and uvc_function_unbind() usb: typec: hd3ss3220: fix VBUS regulator error message usb: usbfs: fix use-after-free of usb_device in usbdev_release() usb: gadget: u_audio: Fix use-after-free on sound card disconnect usb: dwc3: gadget: Fix use-after-free in dwc3_gadget_free_endpoints due to race condition usb: gadget: f_tcm: keep port count until LUN teardown completes usb: usbtest: disable dynamic ID support usb: typec: tcpci: pass correct rx_type to tcpm_pd_receive() USB: c67x00: fix use-after-free in c67x00_add_iso_urb() usb: typec: ucsi: use UCSI_TIMEOUT_MS for sync command completion usb: gadget: snps_udc_plat: clean up PHY on probe deferral usb: gadget: f_tcm: fix deadlock in usbg_make_tpg() usb: dwc2: gadget: Exit partial power down state when changing USB pull-up usb: gadget: f_fs: Fix Use-After-Free in AIO error path usb: gadget: f_fs: Prevent deadlock during ep0 read loop usb: gadget: at91_udc: drain polled-VBUS timer/work before udc is freed usb: gadget: midi2: remove default configfs groups on teardown usb: gadget: uvc: Fix null pointer dereference in uvcg_video_init() usb: typec: thunderbolt: Disable work before freeing tbt on remove usb: xhci: Handle bogus TRB pointers in Missed Service Error events ...

Merge tag 'soc-drivers-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc

2026-08-19T02:40:29+00:00

Pull SoC driver updates from Arnd Bergmann: "The SoC driver changes once more consist of many small fixes and cleanups, that are to a large part the result of automated testing. On platform specific drivers, this includes SoC specific code for xilinx, freescale/nxp, qualcomm, TI, aspeed, omap, tegra, samsung, rockchip, renesas, ixp4xx. In firmware drivers, we see a similar picture for SCMI and qcomtee. Aside from these, we see actual new hardware support in a few areas: - The Apple platform gets a new driver for low power states - Updates to Qualcomm platform drivers add several new hardware specific features and additional SoCs. - Amlogic SoC support for A1 and T7 is added - The Mediatek MMSYS driver is refactored as a cleanup" * tag 'soc-drivers-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (157 commits) soc: qcom: make QCOM_PDR_MSG selectable soc: qcom: ubwc: Fix missing include soc: qcom: ubwc: Fix link error when QCOM_SMEM=n media: iris: Guard the QCOM_UBWC_CONFIG select with QCOM_SMEM drm/msm: Guard the QCOM_UBWC_CONFIG select with QCOM_SMEM dt-bindings: arm: qcom,ids: Add SoC ID for Snapdragon SDM 850 firmware: xilinx: Clear firmware notifiers across kexec transitions firmware: xilinx: Release all peripheral devices from firmware firmware: xilinx: Add support to clear EL3 PM state firmware: xilinx: Propagate actual error from feature check firmware: xilinx: Use TF-A feature check for TF-A-specific APIs bus: fsl-mc: drop unused assignment of acpi_device_id::driver_data soc: fsl: qe: check platform_driver_register() in qe_ic_of_init() phy: lynx-10g: use RCW override procedure for dynamic protocol change soc: fsl: guts: implement the RCW override procedure dt-bindings: fsl: layerscape-dcfg: define DCFG_DCSR region soc: fsl: guts: make fsl_soc_data available after fsl_guts_init() soc: fsl: guts: make it easier to determine on which SoC we are running soc: fsl: guts: add a central fsl_guts_read() function soc: fsl: guts: add a global structure to hold state ...

usb: xhci: Handle bogus TRB pointers in Missed Service Error events

2026-08-14T01:26:41+00:00

xHCI 1.0 allowed these pointers to be zero. Some Intel chipsets from the era usually set it to zero, but sometimes (apparently) to the next TRB after the one referenced by the previous transfer event on the endpoint. Usually that's indeed the missed TD, but it may also be the last TRB of a two-TRB TD already completed with Short Packet on its first TRB. Then the driver skips all pending TDs, failing to find a match. When handling Missed Service Error, scan TD list twice and only really skip TDs in the second pass if the first pass found a match. This won't catch bogus pointers to wrong TDs, but such a bug would be practically impossible to detect automatically and isn't known to exist. Reported-by: Bart Nagel Closes: https://lore.kernel.org/linux-usb/al_hchyOdPoPWKEo@spiral/ Suggested-by: Mathias Nyman Fixes: d0b619599e52 ("usb: xhci: Expedite skipping missed isoch TDs on modern HCs") Cc: stable@vger.kernel.org Signed-off-by: Michal Pecio Signed-off-by: Mathias Nyman Link: https://patch.msgid.link/20260806142113.2436238-18-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: xhci: Handle USB3 port events when there is one roothub

2026-08-14T01:26:41+00:00

handle_port_status() drops every USB3 port event when xhci->shared_hcd is NULL. The check dates from a time when xhci-plat always created a shared hcd, so a NULL one could only mean the hcd had been removed. Since commit 4736ebd7fcaf ("usb: host: xhci-plat: omit shared hcd if either root hub has no ports") that is no longer true. A controller whose USB2 root hub has no ports gets a single roothub, the USB3 rhub is served by the main hcd, and shared_hcd stays NULL for the lifetime of the device. Every SuperSpeed port event is then thrown away as bogus behind a debug message, so devices never enumerate even though the port sees the device and its change bits stay set: 0x006a1203 Powered Connected Enabled Link:U0 PortSpeed:4 Change: CSC WRC PRC PLC Broadcom Northstar is such a controller. USB3 works there up to 5.15 and stops working from 5.19 onwards. Ask xhci_get_usb3_hcd() instead. It returns the shared hcd when there is one, the main hcd when the USB2 root hub has no ports, and NULL once the shared hcd is gone, which keeps the original meaning of the check. Tested on an Asus RT-N18U (BCM47081), which has a single roothub. Before the change nothing enumerates on the USB3 port; after it SuperSpeed devices enumerate normally over repeated connect and disconnect cycles, the change bits shown above clear, and USB2 is unaffected on both ports. Fixes: 4736ebd7fcaf ("usb: host: xhci-plat: omit shared hcd if either root hub has no ports") Cc: stable@vger.kernel.org Signed-off-by: Semih Baskan Signed-off-by: Mathias Nyman Link: https://patch.msgid.link/20260806142113.2436238-17-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: xhci: replace Unicode quotes with ASCII apostrophes

2026-08-14T01:26:41+00:00

Non-ASCII characters trigger git send-email to prompt for encoding on each modification near them, which is unnecessary and annoying. Using plain ASCII avoids these prompts and does not change its meaning. This change only affects comments and has no functional impact. Signed-off-by: Niklas Neronin Signed-off-by: Mathias Nyman Link: https://patch.msgid.link/20260806142113.2436238-16-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: xhci: remove redundant 'xhci' pointer from endpoint struct

2026-08-14T01:26:41+00:00

The 'xhci_virt_ep' struct currently contains a pointer to its parent 'xhci_hcd' struct. Since all endpoint-related structs are contained within 'xhci_hcd', this pointer is redundant. Remove the 'xhci' pointer from 'xhci_virt_ep' and instead pass it explicitly to functions that require it, as some already do it. This change reduces unnecessary complexity and aligns the code with the rest of the xhci driver. Memory impact: For each device connected a struct 'xhci_virt_device' is allocated, this struct conatains a 31 slot array of struct 'xhci_virt_ep'. A USB hub consumes 1 slot, but every downstream device consumes another slot. This means that the total memory saved buy this patch is: Devices * 31 * 8 bytes Signed-off-by: Niklas Neronin Signed-off-by: Mathias Nyman Link: https://patch.msgid.link/20260806142113.2436238-15-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: xhci: remove redundant function wrapper

2026-08-14T01:26:41+00:00

The function ring_doorbell_for_active_rings() rings the doorbell for any rings with pending URBs. It has a trivial wrapper, xhci_ring_doorbell_for_active_rings(), which takes the same arguments and simply calls the former. Since the wrapper adds no functionality, remove it and rename ring_doorbell_for_active_rings() to xhci_ring_doorbell_for_active_rings(). Signed-off-by: Niklas Neronin Signed-off-by: Mathias Nyman Link: https://patch.msgid.link/20260806142113.2436238-14-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman