kernel/linux.git/drivers/comedi, branch v6.19.12

comedi: me4000: Fix potential overrun of firmware buffer

2026-04-11T12:29:52+00:00

commit 3fb43a7a5b44713f892c58ead2e5f3a1bc9f4ee7 upstream. `me4000_xilinx_download()` loads the firmware that was requested by `request_firmware()`. It is possible for it to overrun the source buffer because it blindly trusts the file format. It reads a data stream length from the first 4 bytes into variable `file_length` and reads the data stream contents of length `file_length` from offset 16 onwards. Add a test to ensure that the supplied firmware is long enough to contain the header and the data stream. On failure, log an error and return `-EINVAL`. Note: The firmware loading was totally broken before commit ac584af59945 ("staging: comedi: me4000: fix firmware downloading"), but that is the most sensible target for this fix. Fixes: ac584af59945 ("staging: comedi: me4000: fix firmware downloading") Cc: stable Signed-off-by: Ian Abbott Link: https://patch.msgid.link/20260205133949.71722-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman

comedi: me_daq: Fix potential overrun of firmware buffer

2026-04-11T12:29:51+00:00

commit cc797d4821c754c701d9714b58bea947e31dbbe0 upstream. `me2600_xilinx_download()` loads the firmware that was requested by `request_firmware()`. It is possible for it to overrun the source buffer because it blindly trusts the file format. It reads a data stream length from the first 4 bytes into variable `file_length` and reads the data stream contents of length `file_length` from offset 16 onwards. Although it checks that the supplied firmware is at least 16 bytes long, it does not check that it is long enough to contain the data stream. Add a test to ensure that the supplied firmware is long enough to contain the header and the data stream. On failure, log an error and return `-EINVAL`. Fixes: 85acac61096f9 ("Staging: comedi: add me_daq driver") Cc: stable Signed-off-by: Ian Abbott Link: https://patch.msgid.link/20260205140130.76697-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman

comedi: ni_atmio16d: Fix invalid clean-up after failed attach

2026-04-11T12:29:51+00:00

commit 101ab946b79ad83b36d5cfd47de587492a80acf0 upstream. If the driver's COMEDI "attach" handler function (`atmio16d_attach()`) returns an error, the COMEDI core will call the driver's "detach" handler function (`atmio16d_detach()`) to clean up. This calls `reset_atmio16d()` unconditionally, but depending on where the error occurred in the attach handler, the device may not have been sufficiently initialized to call `reset_atmio16d()`. It uses `dev->iobase` as the I/O port base address and `dev->private` as the pointer to the COMEDI device's private data structure. `dev->iobase` may still be set to its initial value of 0, which would result in undesired writes to low I/O port addresses. `dev->private` may still be `NULL`, which would result in null pointer dereferences. Fix `atmio16d_detach()` by checking that `dev->private` is valid (non-null) before calling `reset_atmio16d()`. This implies that `dev->iobase` was set correctly since that is set up before `dev->private`. Fixes: 2323b276308a ("Staging: comedi: add ni_at_atmio16d driver") Cc: stable Signed-off-by: Ian Abbott Link: https://patch.msgid.link/20260128150011.5006-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman

comedi: Reinit dev->spinlock between attachments to low-level drivers

2026-04-11T12:29:51+00:00

commit 4b9a9a6d71e3e252032f959fb3895a33acb5865c upstream. `struct comedi_device` is the main controlling structure for a COMEDI device created by the COMEDI subsystem. It contains a member `spinlock` containing a spin-lock that is initialized by the COMEDI subsystem, but is reserved for use by a low-level driver attached to the COMEDI device (at least since commit 25436dc9d84f ("Staging: comedi: remove RT code")). Some COMEDI devices (those created on initialization of the COMEDI subsystem when the "comedi.comedi_num_legacy_minors" parameter is non-zero) can be attached to different low-level drivers over their lifetime using the `COMEDI_DEVCONFIG` ioctl command. This can result in inconsistent lock states being reported when there is a mismatch in the spin-lock locking levels used by each low-level driver to which the COMEDI device has been attached. Fix it by reinitializing `dev->spinlock` before calling the low-level driver's `attach` function pointer if `CONFIG_LOCKDEP` is enabled. Reported-by: syzbot+cc9f7f4a7df09f53c4a4@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=cc9f7f4a7df09f53c4a4 Fixes: ed9eccbe8970 ("Staging: add comedi core") Cc: stable Signed-off-by: Ian Abbott Link: https://patch.msgid.link/20260225132427.86578-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman

comedi: runflags cannot determine whether to reclaim chanlist

2026-04-11T12:29:51+00:00

commit 29f644f14b89e6c4965e3c89251929e451190a66 upstream. syzbot reported a memory leak [1], because commit 4e1da516debb ("comedi: Add reference counting for Comedi command handling") did not consider the exceptional exit case in do_cmd_ioctl() where runflags is not set. This caused chanlist not to be properly freed by do_become_nonbusy(), as it only frees chanlist when runflags is correctly set. Added a check in do_become_nonbusy() for the case where runflags is not set, to properly free the chanlist memory. [1] BUG: memory leak backtrace (crc 844a0efa): __comedi_get_user_chanlist drivers/comedi/comedi_fops.c:1815 [inline] do_cmd_ioctl.part.0+0x112/0x350 drivers/comedi/comedi_fops.c:1890 do_cmd_ioctl drivers/comedi/comedi_fops.c:1858 [inline] Fixes: 4e1da516debb ("comedi: Add reference counting for Comedi command handling") Reported-by: syzbot+f238baf6ded841b5a82e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f238baf6ded841b5a82e Signed-off-by: Edward Adam Davis Reviewed-by: Ian Abbott Cc: stable # 6.19 Signed-off-by: Ian Abbott Link: https://patch.msgid.link/20260310111104.70959-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

comedi: dt2815: add hardware detection to prevent crash

2026-04-11T12:29:51+00:00

commit 93853512f565e625df2397f0d8050d6aafd7c3ad upstream. The dt2815 driver crashes when attached to I/O ports without actual hardware present. This occurs because syzkaller or users can attach the driver to arbitrary I/O addresses via COMEDI_DEVCONFIG ioctl. When no hardware exists at the specified port, inb() operations return 0xff (floating bus), but outb() operations can trigger page faults due to undefined behavior, especially under race conditions: BUG: unable to handle page fault for address: 000000007fffff90 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page RIP: 0010:dt2815_attach+0x6e0/0x1110 Add hardware detection by reading the status register before attempting any write operations. If the read returns 0xff, assume no hardware is present and fail the attach with -ENODEV. This prevents crashes from outb() operations on non-existent hardware. Reported-by: syzbot+72f94b474d6e50b71ffc@syzkaller.appspotmail.com Cc: stable Closes: https://syzkaller.appspot.com/bug?extid=72f94b474d6e50b71ffc Tested-by: syzbot+72f94b474d6e50b71ffc@syzkaller.appspotmail.com Reviewed-by: Ian Abbott Signed-off-by: Deepanshu Kartikey Link: [https://lore.kernel.org/all/20260126070458.10974-1-kartikey406@gmail.com/T/] Link: [https://lore.kernel.org/all/20260126070458.10974-1-kartikey406@gmail.com/T/ Link: https://patch.msgid.link/20260309104859.503529-1-kartikey406@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

comedi: dmm32at: serialize use of paged registers

2026-01-16T15:43:51+00:00

Some of the hardware registers of the DMM-32-AT board are multiplexed, using the least significant two bits of the Miscellaneous Control register to select the function of registers at offsets 12 to 15: 00 => 8254 timer/counter registers are accessible 01 => 8255 digital I/O registers are accessible 10 => Reserved 11 => Calibration registers are accessible The interrupt service routine (`dmm32at_isr()`) clobbers the bottom two bits of the register with value 00, which would interfere with access to the 8255 registers by the `dm32at_8255_io()` function (used for Comedi instruction handling on the digital I/O subdevice). Make use of the generic Comedi device spin-lock `dev->spinlock` (which is otherwise unused by this driver) to serialize access to the miscellaneous control register and paged registers. Fixes: 3c501880ac44 ("Staging: comedi: add dmm32at driver") Cc: stable@vger.kernel.org Signed-off-by: Ian Abbott Link: https://patch.msgid.link/20260112162835.91688-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman

comedi: Fix getting range information for subdevices 16 to 255

2026-01-16T15:42:15+00:00

The `COMEDI_RANGEINFO` ioctl does not work properly for subdevice indices above 15. Currently, the only in-tree COMEDI drivers that support more than 16 subdevices are the "8255" driver and the "comedi_bond" driver. Making the ioctl work for subdevice indices up to 255 is achievable. It needs minor changes to the handling of the `COMEDI_RANGEINFO` and `COMEDI_CHANINFO` ioctls that should be mostly harmless to user-space, apart from making them less broken. Details follow... The `COMEDI_RANGEINFO` ioctl command gets the list of supported ranges (usually with units of volts or milliamps) for a COMEDI subdevice or channel. (Only some subdevices have per-channel range tables, indicated by the `SDF_RANGETYPE` flag in the subdevice information.) It uses a `range_type` value and a user-space pointer, both supplied by user-space, but the `range_type` value should match what was obtained using the `COMEDI_CHANINFO` ioctl (if the subdevice has per-channel range tables) or `COMEDI_SUBDINFO` ioctl (if the subdevice uses a single range table for all channels). Bits 15 to 0 of the `range_type` value contain the length of the range table, which is the only part that user-space should care about (so it can use a suitably sized buffer to fetch the range table). Bits 23 to 16 store the channel index, which is assumed to be no more than 255 if the subdevice has per-channel range tables, and is set to 0 if the subdevice has a single range table. For `range_type` values produced by the `COMEDI_SUBDINFO` ioctl, bits 31 to 24 contain the subdevice index, which is assumed to be no more than 255. But for `range_type` values produced by the `COMEDI_CHANINFO` ioctl, bits 27 to 24 contain the subdevice index, which is assumed to be no more than 15, and bits 31 to 28 contain the COMEDI device's minor device number for some unknown reason lost in the mists of time. The `COMEDI_RANGEINFO` ioctl extract the length from bits 15 to 0 of the user-supplied `range_type` value, extracts the channel index from bits 23 to 16 (only used if the subdevice has per-channel range tables), extracts the subdevice index from bits 27 to 24, and ignores bits 31 to 28. So for subdevice indices 16 to 255, the `COMEDI_SUBDINFO` or `COMEDI_CHANINFO` ioctl will report a `range_type` value that doesn't work with the `COMEDI_RANGEINFO` ioctl. It will either get the range table for the subdevice index modulo 16, or will fail with `-EINVAL`. To fix this, always use bits 31 to 24 of the `range_type` value to hold the subdevice index (assumed to be no more than 255). This affects the `COMEDI_CHANINFO` and `COMEDI_RANGEINFO` ioctls. There should not be anything in user-space that depends on the old, broken usage, although it may now see different values in bits 31 to 28 of the `range_type` values reported by the `COMEDI_CHANINFO` ioctl for subdevices that have per-channel subdevices. User-space should not be trying to decode bits 31 to 16 of the `range_type` values anyway. Fixes: ed9eccbe8970 ("Staging: add comedi core") Cc: stable@vger.kernel.org #5.17+ Signed-off-by: Ian Abbott Link: https://patch.msgid.link/20251203162438.176841-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman

Merge tag 'char-misc-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2025-12-07T02:34:24+00:00

Pull char/misc/IIO driver updates from Greg KH: "Here is the big set of char/misc/iio driver updates for 6.19-rc1. Lots of stuff in here including: - lots of IIO driver updates, cleanups, and additions - large interconnect driver changes as they get converted over to a dynamic system of ids - coresight driver updates - mwave driver updates - binder driver updates and changes - comedi driver fixes now that the fuzzers are being set loose on them - nvmem driver updates - new uio driver addition - lots of other small char/misc driver updates, full details in the shortlog All of these have been in linux-next for a while now" * tag 'char-misc-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (304 commits) char: applicom: fix NULL pointer dereference in ac_ioctl hangcheck-timer: fix coding style spacing hangcheck-timer: Replace %Ld with %lld hangcheck-timer: replace printk(KERN_CRIT) with pr_crit uio: Add SVA support for PCI devices via uio_pci_generic_sva.c dt-bindings: slimbus: fix warning from example intel_th: Fix error handling in intel_th_output_open misc: rp1: Fix an error handling path in rp1_probe() char: xillybus: add WQ_UNBOUND to alloc_workqueue users misc: bh1770glc: use pm_runtime_resume_and_get() in power_state_store misc: cb710: Fix a NULL vs IS_ERR() check in probe() mux: mmio: Add suspend and resume support virt: acrn: split acrn_mmio_dev_res out of acrn_mmiodev greybus: gb-beagleplay: Fix timeout handling in bootloader functions greybus: add WQ_PERCPU to alloc_workqueue users char/mwave: drop typedefs char/mwave: drop printk wrapper char/mwave: remove printk tracing char/mwave: remove unneeded fops char/mwave: remove MWAVE_FUTZ_WITH_OTHER_DEVICES ifdeffery ...

Merge tag 'hardening-v6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2025-12-05T17:11:02+00:00

Pull hardening updates from Kees Cook: - string: Add missing kernel-doc return descriptions (Kriish Sharma) - Update some mis-typed allocations These correct some accidentally wrong types used in allocations (that didn't affect the resulting size) that never got picked up from the batch I sent a few months ago. - Enable GCC diagnostic context for value-tracking warnings This results in better GCC diagnostics for the value range tracking, so we can get better visibility into where those values are coming from when we get out-of-bounds warnings at compile time. * tag 'hardening-v6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: kbuild: Enable GCC diagnostic context for value-tracking warnings string: Add missing kernel-doc return descriptions media: iris: Cast iris_hfi_gen2_get_instance() allocation type drm/plane: Remove const qualifier from plane->modifiers allocation type comedi: Adjust range_table_list allocation type