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

Merge branch 'usb-next' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial.git

2026-09-08T19:28:59+00:00

USB: serial: wwan: replace __get_free_page() with kmalloc()

2026-09-08T09:08:17+00:00

usb_wwan_port_probe() allocates the transfer buffers for the read URBs. These buffers can be allocated with kmalloc() as there's nothing special about them to go directly to the page allocator. kmalloc() provides a better API that does not require ugly casts and kfree() does not need to know the size of the freed object. Performance difference between kmalloc() and __get_free_pages() is not measurable as both allocators take an object/page from a per-CPU list for fast path allocations. For the slow path the performance is anyway determined by the amount of reclaim involved rather than by what allocator is used. While on it, allocate IN_BUFLEN bytes rather than a full page. IN_BUFLEN is the transfer_buffer_length of the read URBs, the page allocator was only used because IN_BUFLEN happens to equal PAGE_SIZE on x86. Replace use of __get_free_page() with kmalloc() and free_page() with kfree(). Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com Assisted-by: copilot:claude-opus Signed-off-by: Mike Rapoport (Microsoft) Signed-off-by: Johan Hovold

USB: serial: fix ioctl hangup race

2026-09-08T09:00:48+00:00

The tty ioctls can race with hangup and end up calling into a tty driver for a device that is already gone or powered down. Serialise the callbacks using the tty port mutex and add the missing checks to make sure the port has not been hung up before accessing port driver data or hardware. This specifically avoids dereferencing a NULL-pointer if a device is disconnected during lengthy break signalling. Note that TIOCGICOUNT and TIOCMIWAIT do not access port driver data or hardware and are therefore not affected by the race. Fixes: f34d7a5b7010 ("tty: The big operations rework") Reported-by: Nick Bowler Link: https://lore.kernel.org/all/CADyTPExB2kYOOwkO0JqGhKaYVDqO9uS9WCw0J=MCTdVhcGOogA@mail.gmail.com/ Reported-by: syzbot+473d7477c523b41d4046@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/6a9087a4.4d659fcc.734b4.0013.GAE@google.com Cc: stable@vger.kernel.org # 2.6.26 Signed-off-by: Johan Hovold

USB: serial: use iterator for driver deregistration

2026-09-08T09:00:48+00:00

Use the new serial driver iterator variable also when deregistering serial drivers to improve readability. Signed-off-by: Johan Hovold

USB: serial: fix driver deregistration order

2026-09-08T09:00:48+00:00

USB serial driver modules register one driver for the USB bus and one or more drivers for the ports on the USB serial bus. When unloading a driver module, the USB driver must be deregistered before the USB serial bus drivers so that I/O is stopped before unbinding the ports to avoid use-after-free in completion handlers accessing port data. Note that the "new_id" attributes must first be removed to prevent new ids from being added and triggering a probe of the USB driver after it has been deregistered. Fixes: 765e0ba62613 ("usb-serial: new API for driver registration") Cc: stable@vger.kernel.org # 3.4 Cc: Alan Stern Signed-off-by: Johan Hovold

USB: serial: fix dynamic id driver deregistration race

2026-09-08T09:00:48+00:00

Only free the dynamic ids after having deregistered the driver and removed the "new_id" attribute to avoid leaking any id added by a racing write to the attribute. Fixes: 93bacefc4cc0 ("USB serial: add dynamic id support to usb-serial core") Cc: stable@vger.kernel.org # 2.6.21 Signed-off-by: Johan Hovold

USB: serial: fix port tear down use-after-free

2026-09-08T09:00:48+00:00

Some drivers for multiport devices access port driver data from completion handlers of shared URBs submitted at attach() or first open() and stopped at disconnect() or last close(), respectively. A simple NULL check before accessing the driver data makes sure that a port state container has at least been allocated, but a completion handler can still race with port tear down. Reorder the disconnect handling so that ports are not deregistered (and their driver data freed) until after all ports have been hung up and the driver disconnect() callback has run so that all I/O has been stopped. Fixes: 2d93148ab698 ("USB: serial: fix lifetime and locking problems") Reported-by: syzbot+e5e28c3e953b2eebb16e@syzkaller.appspotmail.com Link: https://lore.kernel.org/all/6a7e6fb9.ec5dc6cc.21cb3f.00c0.GAE@google.com/ Cc: stable@vger.kernel.org # 2.6.30 Cc: Alan Stern Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold

USB: serial: option: add Compal EXC-T1 support

2026-09-08T09:00:48+00:00

The Compal EXC-T1 is a Qualcomm MDM9207-based LTE modem which reports "EXC-x1" as its USB product string. It exposes diagnostic, modem, AT, and NMEA ports as vendor-specific interfaces with subclass 0x10 and protocols 0x01 through 0x04. Add exact interface matches for these four ports, leaving the ff/ff/ff interface unbound. Relevant output from usb-devices: T: Bus=03 Lev=02 Prnt=03 Port=03 Cnt=01 Dev#= 6 Spd=480 MxCh= 0 D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 P: Vendor=04b7 ProdID=4d22 Rev=03.18 S: Manufacturer=CEI S: Product=EXC-x1 C: #Ifs= 6 Cfg#= 1 Atr=a0 MxPwr=500mA I: If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=10 Prot=01 Driver=option I: If#= 1 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=10 Prot=02 Driver=option I: If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=10 Prot=03 Driver=option I: If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=10 Prot=04 Driver=option I: If#= 4 Alt= 0 #EPs= 1 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none) I: If#= 5 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=10 Prot=05 Driver=qmi_wwan Tested on a Compal EXC-T1 modem using an Ubuntu kernel build. The four serial interfaces bound to option and exposed ttyUSB3 through ttyUSB6. Assisted-by: Codex:GPT-5 Signed-off-by: Ian Lin Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold

USB: serial: option: add Quectel RG660QB

2026-09-04T07:04:02+00:00

Add support for the Quectel RG660QB 5G module (USB ID 2c7c:013d). The interface layout is the same as the RG650V: If 0: DIAG ff/ff/30, 2 endpoints If 1: NMEA ff/00/00, 2 endpoints If 2: AT ff/00/00, 3 endpoints If 3: Modem ff/00/00, 3 endpoints If 4: QMI ff/ff/ff, 3 endpoints Match the serial interfaces on class/subclass/protocol so that the QMI interface is left to qmi_wwan. # lsusb -v -d 2c7c:013d Bus 004 Device 002: ID 2c7c:013d Quectel Wireless Solutions Co., Ltd. RG660QB-EU Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 3.20 bDeviceClass 0 bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 9 idVendor 0x2c7c Quectel Wireless Solutions Co., Ltd. idProduct 0x013d bcdDevice 6.06 iManufacturer 1 Quectel iProduct 2 RG660QB-EU iSerial 3 f50119d0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 0x0105 bNumInterfaces 5 bConfigurationValue 1 iConfiguration 4 DIAG_SER_RMNET bmAttributes 0xa0 (Bus Powered) Remote Wakeup MaxPower 896mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 255 Vendor Specific Subclass bInterfaceProtocol 48 iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x01 EP 1 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 0 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 0 bInterfaceProtocol 0 iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x82 EP 2 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x02 EP 2 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 0 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 bAlternateSetting 0 bNumEndpoints 3 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 0 bInterfaceProtocol 0 iInterface 6 CDEV Serial ** UNRECOGNIZED: 05 24 00 10 01 ** UNRECOGNIZED: 05 24 01 00 00 ** UNRECOGNIZED: 04 24 02 02 ** UNRECOGNIZED: 05 24 06 00 00 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x84 EP 4 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x000a 1x 10 bytes bInterval 9 bMaxBurst 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x03 EP 3 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 0 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 3 bAlternateSetting 0 bNumEndpoints 3 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 0 bInterfaceProtocol 0 iInterface 6 CDEV Serial ** UNRECOGNIZED: 05 24 00 10 01 ** UNRECOGNIZED: 05 24 01 00 00 ** UNRECOGNIZED: 04 24 02 02 ** UNRECOGNIZED: 05 24 06 00 00 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x86 EP 6 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x000a 1x 10 bytes bInterval 9 bMaxBurst 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x85 EP 5 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x04 EP 4 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 0 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 4 bAlternateSetting 0 bNumEndpoints 3 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 255 Vendor Specific Subclass bInterfaceProtocol 255 Vendor Specific Protocol iInterface 7 RmNet Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x88 EP 8 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0008 1x 8 bytes bInterval 9 bMaxBurst 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x87 EP 7 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 6 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x05 EP 5 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0400 1x 1024 bytes bInterval 0 bMaxBurst 2 Binary Object Store Descriptor: bLength 5 bDescriptorType 15 wTotalLength 0x0023 bNumDeviceCaps 2 SuperSpeed USB Device Capability: bLength 10 bDescriptorType 16 bDevCapabilityType 3 bmAttributes 0x00 wSpeedsSupported 0x000f Device can operate at Low Speed (1Mbps) Device can operate at Full Speed (12Mbps) Device can operate at High Speed (480Mbps) Device can operate at SuperSpeed (5Gbps) bFunctionalitySupport 1 Lowest fully-functional device speed is Full Speed (12Mbps) bU1DevExitLat 0 micro seconds bU2DevExitLat 0 micro seconds SuperSpeedPlus USB Device Capability: bLength 20 bDescriptorType 16 bDevCapabilityType 10 bmAttributes 0x00000001 Sublink Speed Attribute count 1 Sublink Speed ID count 0 wFunctionalitySupport 0x1100 bmSublinkSpeedAttr[0] 0x000a4030 Speed Attribute ID: 0 10Gb/s Symmetric RX SuperSpeedPlus bmSublinkSpeedAttr[1] 0x000a40b0 Speed Attribute ID: 0 10Gb/s Symmetric TX SuperSpeedPlus Device Status: 0x0000 (Bus Powered) Tested with an early sample of the module on a Quectel 5G EVB connected over USB 3 to a Raspberry Pi 5. Assisted-by: LLM Signed-off-by: Sebastian Sjoholm Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold

USB: serial: option: add Compal EXM-G1x support

2026-09-03T15:48:19+00:00

The Compal EXM-G1x is a Qualcomm SDX12-based LTE modem. Add support for its vendor-specific serial interfaces with protocols 0x30, 0x40, and 0x60. Relevant output from usb-devices: T: Bus=04 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 4 Spd=5000 MxCh= 0 D: Ver= 3.20 Cls=ef(misc ) Sub=02 Prot=01 MxPS= 9 #Cfgs= 1 P: Vendor=04b7 ProdID=8217 Rev=05.04 S: Manufacturer=COMPAL S: Product=EXM-G1x C: #Ifs= 6 Cfg#= 1 Atr=a0 MxPwr=896mA I: If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=30 Driver=option I: If#= 1 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=42 Prot=01 Driver=(none) I: If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=60 Driver=option I: If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=40 Driver=option I: If#= 4 Alt= 0 #EPs= 1 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none) I: If#= 8 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=50 Driver=qmi_wwan Tested on a Compal EXM-G1x modem. Assisted-by: Codex:GPT-5 Signed-off-by: Ian Lin Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold