Kernel recognizes USB device but then I can't find it in /sys or /dev

You'll likely need to add a UDEV rule to detect this devices presences. Once the device is detected, UDEV can create the corresponding /dev/sdb1 to go along with it.

These docs from OpenSUSE should get you started in the creation of this rule.

• Chapter 13. Dynamic Kernel Device Management with udev

Regarding your question:

"... but don't I need to be able to find the parent node in /sys for that? And I can't find anything..."

I would expect that if the kernel has successfully detected /dev/sdb1, which it has since you're getting those messages in your dmesg log, then you'd have corresponding entries under /sys.

I would investigate the /sys more thoroughly, there is likely a device handle hiding in there that corresponds to /dev/sdb1. You can walk around the tree using this command: udevadm info -a -p /sys/class/... you'll need to add on the appropriate device in place of the dots (...).

Example

$ udevadm info -a -p /sys/class/ata_device/dev1.0 Udevadm info starts with the device specified by the devpath and then walks up the chain of parent devices. It prints for every device found, all possible attributes in the udev rules key format. A rule to match, can be composed by the attributes of the device and the attributes from one single parent device. looking at device '/devices/pci0000:00/0000:00:1f.2/ata1/link1/dev1.0/ata_device/dev1.0': KERNEL=="dev1.0" SUBSYSTEM=="ata_device" DRIVER=="" ATTR{gscr}=="" ATTR{class}=="ata" ATTR{ering}=="[4294667.658000000]Unknown" ATTR{spdn_cnt}=="0" ATTR{pio_mode}=="XFER_UDMA_7, XFER_UDMA_6, XFER_UDMA_5, XFER_UDMA_4, XFER_MW_DMA_4, XFER_PIO_6, XFER_PIO_5, XFER_PIO_4, XFER_PIO_3, XFER_PIO_2, XFER_PIO_1, XFER_PIO_0" ATTR{dma_mode}=="XFER_UDMA_7, XFER_UDMA_6, XFER_UDMA_5, XFER_UDMA_4, XFER_UDMA_3, XFER_UDMA_2, XFER_UDMA_1, XFER_UDMA_0, XFER_MW_DMA_4, XFER_MW_DMA_3, XFER_MW_DMA_2, XFER_SW_DMA_2, XFER_PIO_6, XFER_PIO_5, XFER_PIO_4, XFER_PIO_3, XFER_PIO_2" ATTR{xfer_mode}=="XFER_UDMA_7, XFER_UDMA_6, XFER_UDMA_5, XFER_UDMA_4, XFER_UDMA_3, XFER_UDMA_2, XFER_UDMA_1, XFER_UDMA_0, XFER_MW_DMA_4, XFER_MW_DMA_3, XFER_MW_DMA_2, XFER_SW_DMA_2, XFER_PIO_6, XFER_PIO_5, XFER_PIO_4, XFER_PIO_3, XFER_PIO_2" looking at parent device '/devices/pci0000:00/0000:00:1f.2/ata1/link1/dev1.0': KERNELS=="dev1.0" SUBSYSTEMS=="" DRIVERS=="" looking at parent device '/devices/pci0000:00/0000:00:1f.2/ata1/link1': KERNELS=="link1" SUBSYSTEMS=="" DRIVERS=="" looking at parent device '/devices/pci0000:00/0000:00:1f.2/ata1': KERNELS=="ata1" SUBSYSTEMS=="" DRIVERS=="" looking at parent device '/devices/pci0000:00/0000:00:1f.2': KERNELS=="0000:00:1f.2" SUBSYSTEMS=="pci" DRIVERS=="ahci" ATTRS{irq}=="40" ATTRS{subsystem_vendor}=="0x17aa" ATTRS{broken_parity_status}=="0" ATTRS{class}=="0x010601" ATTRS{consistent_dma_mask_bits}=="64" ATTRS{dma_mask_bits}=="64" ATTRS{local_cpus}=="00000000,00000000,00000000,0000000f" ATTRS{device}=="0x3b2f" ATTRS{msi_bus}=="" ATTRS{local_cpulist}=="0-3" ATTRS{vendor}=="0x8086" ATTRS{subsystem_device}=="0x2168" ATTRS{numa_node}=="-1" ATTRS{d3cold_allowed}=="1" looking at parent device '/devices/pci0000:00': KERNELS=="pci0000:00" SUBSYSTEMS=="" DRIVERS==""