linux.git/kernel/params.c, branch v5.10.258

module: ensure that kobject_put() is safe for module type kobjects

2025-06-04T12:36:55+00:00

commit a6aeb739974ec73e5217c75a7c008a688d3d5cf1 upstream.

In 'lookup_or_create_module_kobject()', an internal kobject is created
using 'module_ktype'. So call to 'kobject_put()' on error handling
path causes an attempt to use an uninitialized completion pointer in
'module_kobject_release()'. In this scenario, we just want to release
kobject without an extra synchronization required for a regular module
unloading process, so adding an extra check whether 'complete()' is
actually required makes 'kobject_put()' safe.

Reported-by: syzbot+7fb8a372e1f6add936dd@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7fb8a372e1f6add936dd
Fixes: 942e443127e9 ("module: Fix mod->mkobj.kobj potentially freed too early")
Cc: stable@vger.kernel.org
Suggested-by: Petr Pavlu 
Signed-off-by: Dmitry Antipov 
Link: https://lore.kernel.org/r/20250507065044.86529-1-dmantipov@yandex.ru
Signed-off-by: Petr Pavlu 
Signed-off-by: Greg Kroah-Hartman

params: lift param_set_uint_minmax to common code

2024-06-16T11:32:26+00:00

[ Upstream commit 2a14c9ae15a38148484a128b84bff7e9ffd90d68 ]

It is a useful helper hence move it to common code so others can enjoy
it.

Suggested-by: Christoph Hellwig 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Sagi Grimberg 
Signed-off-by: Christoph Hellwig 
Stable-dep-of: 3ebc46ca8675 ("tcp: Fix shift-out-of-bounds in dctcp_update_alpha().")
Signed-off-by: Sasha Levin

params: Replace zero-length array with flexible-array member

2020-10-29T22:22:59+00:00

There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays

Signed-off-by: Gustavo A. R. Silva

moduleparams: Add hexint type parameter

2020-07-28T11:44:53+00:00

For bitmasks printing values in hex is more convenient.

Prefix with `0x` to make it clear, that it’s a hex value, and pad it
out.

Using the helper for `amdgpu.ppfeaturemask`, it will look like below.

Before:

    $ more /sys/module/amdgpu/parameters/ppfeaturemask
    4294950911

After:

    $ more /sys/module/amdgpu/parameters/ppfeaturemask
    0xffffbfff

Cc: linux-kernel@vger.kernel.org
Cc: amd-gfx@lists.freedesktop.org
Signed-off-by: Paul Menzel 
Acked-by: Linus Torvalds 
Reviewed-by: Christian König 
Signed-off-by: Christian König 
Link: https://patchwork.freedesktop.org/patch/374726/

kernel/params.c: Align last argument with a tab

2020-07-28T11:43:56+00:00

The second and third arguments are aligned with tabs, so do the same for
the fourth.

Cc: linux-kernel@vger.kernel.org
Signed-off-by: Paul Menzel 
Reviewed-by: Christian König 
Signed-off-by: Christian König 
Link: https://lore.kernel.org/patchwork/patch/1267600/

lockdown: Lock down module params that specify hardware parameters (eg. ioport)

2019-08-20T04:54:16+00:00

Provided an annotation for module parameters that specify hardware
parameters (such as io ports, iomem addresses, irqs, dma channels, fixed
dma buffers and other types).

Suggested-by: Alan Cox 
Signed-off-by: David Howells 
Signed-off-by: Matthew Garrett 
Reviewed-by: Kees Cook 
Cc: Jessica Yu 
Signed-off-by: James Morris

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman

kernel/params.c: downgrade warning for unsafe parameters

2018-04-11T17:28:37+00:00

As using an unsafe module parameter is, by its very definition, an
expected user action, emitting a warning is overkill.  Nothing has yet
gone wrong, and we add a taint flag for any future oops should something
actually go wrong.  So instead of having a user controllable pr_warn,
downgrade it to a pr_notice for "a normal, but significant condition".

We make use of unsafe kernel parameters in igt
(https://cgit.freedesktop.org/drm/igt-gpu-tools/) (we have not yet
succeeded in removing all such debugging options), which generates a
warning and taints the kernel.  The warning is unhelpful as we then need
to filter it out again as we check that every test themselves do not
provoke any kernel warnings.

Link: http://lkml.kernel.org/r/20180226151919.9674-1-chris@chris-wilson.co.uk
Fixes: 91f9d330cc14 ("module: make it possible to have unsafe, tainting module params")
Signed-off-by: Chris Wilson 
Acked-by: Jani Nikula 
Reviewed-by: Andrew Morton 
Cc: Rusty Russell 
Cc: Jean Delvare 
Cc: Li Zhong 
Cc: Petri Latvala 
Cc: Daniel Vetter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kernel/params.c: improve STANDARD_PARAM_DEF readability

2017-10-04T00:54:26+00:00

Align the parameters passed to STANDARD_PARAM_DEF for clarity.

Link: http://lkml.kernel.org/r/20170928162728.756143cc@endymion
Signed-off-by: Jean Delvare 
Suggested-by: Ingo Molnar 
Acked-by: Ingo Molnar 
Cc: Baoquan He 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kernel/params.c: fix an overflow in param_attr_show

2017-10-04T00:54:26+00:00

Function param_attr_show could overflow the buffer it is operating on.

The buffer size is PAGE_SIZE, and the string returned by
attribute->param->ops->get is generated by scnprintf(buffer, PAGE_SIZE,
...) so it could be PAGE_SIZE - 1 long, with the terminating '\0' at the
very end of the buffer.  Calling strcat(..., "\n") on this isn't safe, as
the '\0' will be replaced by '\n' (OK) and then another '\0' will be added
past the end of the buffer (not OK.)

Simply add the trailing '\n' when writing the attribute contents to the
buffer originally.  This is safe, and also faster.

Credits to Teradata for discovering this issue.

Link: http://lkml.kernel.org/r/20170928162602.60c379c7@endymion
Signed-off-by: Jean Delvare 
Acked-by: Ingo Molnar 
Cc: Baoquan He 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds