gpib: fix use-after-free in IO ioctl handlers

The IBRD, IBWRT, IBCMD, and IBWAIT ioctl handlers use a gpib_descriptor
pointer after board->big_gpib_mutex has been released. A concurrent
IBCLOSEDEV

gpib: fix use-after-free in IO ioctl handlers

The IBRD, IBWRT, IBCMD, and IBWAIT ioctl handlers use a gpib_descriptor
pointer after board->big_gpib_mutex has been released. A concurrent
IBCLOSEDEV ioctl can free the descriptor via close_dev_ioctl() during
this window, causing a use-after-free.

The IO handlers (read_ioctl, write_ioctl, command_ioctl) explicitly
release big_gpib_mutex before calling their handler. wait_ioctl() is
called with big_gpib_mutex held, but ibwait() releases it internally
when wait_mask is non-zero. In all four cases, the descriptor pointer
obtained from handle_to_descriptor() becomes unprotected.

Fix this by introducing a kernel-only descriptor_busy reference count
in struct gpib_descriptor. Each handler atomically increments
descriptor_busy under file_priv->descriptors_mutex before releasing the
lock, and decrements it when done. close_dev_ioctl() checks
descriptor_busy under the same lock and rejects the close with -EBUSY
if the count is non-zero.

A reference count rather than a simple flag is necessary because
multiple handlers can operate on the same descriptor concurrently
(e.g. IBRD and IBWAIT on the same handle from different threads).

A separate counter is needed because io_in_progress can be cleared from
unprivileged userspace via the IBWAIT ioctl (through general_ibstatus()
with set_mask containing CMPL), which would allow an attacker to bypass
a check based solely on io_in_progress. The new descriptor_busy
counter is only modified by the kernel IO paths.

The lock ordering is consistent (big_gpib_mutex -> descriptors_mutex)
and the handlers only hold descriptors_mutex briefly during the lookup,
so there is no deadlock risk and no impact on IO throughput.

Signed-off-by: Adam Crosser <adam.crosser@praetorian.com>
Cc: stable <stable@kernel.org>
Reviewed-by: Dave Penkler <dpenkler@gmail.com>
Tested-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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gpib: lpvo_usb: fix memory leak on disconnect

The driver iterates over the registered USB interfaces during GPIB
attach and takes a reference to their USB devices until a match is
found. These refer

gpib: lpvo_usb: fix memory leak on disconnect

The driver iterates over the registered USB interfaces during GPIB
attach and takes a reference to their USB devices until a match is
found. These references are never released which leads to a memory leak
when devices are disconnected.

Fix the leak by dropping the unnecessary references.

Fixes: fce79512a96a ("staging: gpib: Add LPVO DIY USB GPIB driver")
Cc: stable <stable@kernel.org> # 6.13
Cc: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://patch.msgid.link/20260310105127.17538-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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gpib: Fix fluke driver s390 compile issue

The following errors were reported for a s390 randconfig build
of the fluke gpib driver:

>> drivers/gpib/eastwood/fluke_gpib.c:1002:23: error: call to unde

gpib: Fix fluke driver s390 compile issue

The following errors were reported for a s390 randconfig build
of the fluke gpib driver:

>> drivers/gpib/eastwood/fluke_gpib.c:1002:23: error: call to undeclared function 'ioremap'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
1002 | nec_priv->mmiobase = ioremap(e_priv->gpib_iomem_res->start,
| ^
>> drivers/gpib/eastwood/fluke_gpib.c:1002:21: error: incompatible integer to pointer conversion assigning to 'void *' from 'int' [-Wint-conversion]
1002 | nec_priv->mmiobase = ioremap(e_priv->gpib_iomem_res->start,
| ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1003 | resource_size(e_priv->gpib_iomem_res));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpib/eastwood/fluke_gpib.c:1036:33: error: incompatible integer to pointer conversion assigning to 'void *' from 'int' [-Wint-conversion]
1036 | e_priv->write_transfer_counter = ioremap(e_priv->write_transfer_counter_res->start,
| ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1037 | resource_size(e_priv->write_transfer_counter_res));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Add HAS_IOMEM dependency to Kconfig for fluke driver option

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202601221748.AFAqHieJ-lkp@intel.com/
Fixes: baf8855c9160 ("staging: gpib: fix address space mixup")
Cc: stable <stable@kernel.org>
Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Link: https://patch.msgid.link/20260202094755.4259-1-dpenkler@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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gpib: lpvo_usb: fix unintended binding of FTDI 8U232AM devices

The LPVO USB GPIB adapter apparently uses an FTDI 8U232AM with the
default PID, but this device id is already handled by the ftdi_sio
s

gpib: lpvo_usb: fix unintended binding of FTDI 8U232AM devices

The LPVO USB GPIB adapter apparently uses an FTDI 8U232AM with the
default PID, but this device id is already handled by the ftdi_sio
serial driver.

Stop binding to the default PID to avoid breaking existing setups with
FTDI 8U232AM.

Anyone using this driver should blacklist the ftdi_sio driver and add
the device id manually through sysfs (e.g. using udev rules).

Fixes: fce79512a96a ("staging: gpib: Add LPVO DIY USB GPIB driver")
Fixes: e6ab504633e4 ("staging: gpib: Destage gpib")
Cc: Dave Penkler <dpenkler@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://patch.msgid.link/20260305151729.10501-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Convert more 'alloc_obj' cases to default GFP_KERNEL arguments

This converts some of the visually simpler cases that have been split
over multiple lines. I only did the ones that are easy to verify

Convert more 'alloc_obj' cases to default GFP_KERNEL arguments

This converts some of the visually simpler cases that have been split
over multiple lines. I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.

Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script. I probably had made it a bit _too_ trivial.

So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.

The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

This was done entirely with mindless brute force, using

git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

This was done entirely with mindless brute force, using

git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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