linux.git/kernel/params.c, branch v6.12.81

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

2025-05-18T06:24:54+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

kernel: globalize lookup_or_create_module_kobject()

2025-05-09T07:50:52+00:00

[ Upstream commit 7c76c813cfc42a7376378a0c4b7250db2eebab81 ]

lookup_or_create_module_kobject() is marked as static and __init,
to make it global drop static keyword.
Since this function can be called from non-init code, use __modinit
instead of __init, __modinit marker will make it __init if
CONFIG_MODULES is not defined.

Suggested-by: Rasmus Villemoes 
Signed-off-by: Shyam Saini 
Link: https://lore.kernel.org/r/20250227184930.34163-4-shyamsaini@linux.microsoft.com
Signed-off-by: Petr Pavlu 
Stable-dep-of: f95bbfe18512 ("drivers: base: handle module_kobject creation")
Signed-off-by: Sasha Levin

kernel: param: rename locate_module_kobject

2025-05-09T07:50:52+00:00

[ Upstream commit bbc9462f0cb0c8917a4908e856731708f0cee910 ]

The locate_module_kobject() function looks up an existing
module_kobject for a given module name. If it cannot find the
corresponding module_kobject, it creates one for the given name.

This commit renames locate_module_kobject() to
lookup_or_create_module_kobject() to better describe its operations.

This doesn't change anything functionality wise.

Suggested-by: Rasmus Villemoes 
Signed-off-by: Shyam Saini 
Link: https://lore.kernel.org/r/20250227184930.34163-2-shyamsaini@linux.microsoft.com
Signed-off-by: Petr Pavlu 
Stable-dep-of: f95bbfe18512 ("drivers: base: handle module_kobject creation")
Signed-off-by: Sasha Levin

params: Fix multi-line comment style

2023-12-01T17:51:44+00:00

The multi-line comment style in the file is rather arbitrary.
Make it follow the standard one.

Reviewed-by: Luis Chamberlain 
Reviewed-by: Kees Cook 
Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20231120151419.1661807-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Kees Cook

params: Sort headers

2023-12-01T17:51:44+00:00

Sort the headers in alphabetic order in order to ease
the maintenance for this part.

Reviewed-by: Luis Chamberlain 
Reviewed-by: Kees Cook 
Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20231120151419.1661807-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Kees Cook

params: Use size_add() for kmalloc()

2023-12-01T17:51:43+00:00

Prevent allocations from integer overflow by using size_add().

Reviewed-by: Luis Chamberlain 
Reviewed-by: Kees Cook 
Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20231120151419.1661807-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Kees Cook

params: Do not go over the limit when getting the string length

2023-12-01T17:51:43+00:00

We can use strnlen() even on early stages and it prevents from
going over the string boundaries in case it's already too long.

Reviewed-by: Luis Chamberlain 
Reviewed-by: Kees Cook 
Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20231120151419.1661807-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Kees Cook

params: Introduce the param_unknown_fn type

2023-12-01T17:51:43+00:00

Introduce a new type for the callback to parse an unknown argument.
This unifies function prototypes which takes that as a parameter.

Reviewed-by: Luis Chamberlain 
Reviewed-by: Kees Cook 
Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20231120151419.1661807-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Kees Cook

kernel: params: Remove unnecessary ‘0’ values from err

2023-07-10T19:47:01+00:00

err is assigned first, so it does not need to initialize the assignment.

Signed-off-by: Li zeming 
Reviewed-by: Randy Dunlap 
Signed-off-by: Luis Chamberlain

kallsyms: Replace all non-returning strlcpy with strscpy

2023-06-14T19:27:38+00:00

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh 
Reviewed-by: Kees Cook 
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20230614010354.1026096-1-azeemshaikh38@gmail.com