linux-stable.git/kernel/params.c, branch v6.18.33

module: Fix freeing of charp module parameters when CONFIG_SYSFS=n

2026-05-23T11:06:26+00:00

[ Upstream commit deffe1edba626d474fef38007c03646ca5876a0e ]

When setting a charp module parameter, the param_set_charp() function
allocates memory to store a copy of the input value. Later, when the module
is potentially unloaded, the destroy_params() function is called to free
this allocated memory.

However, destroy_params() is available only when CONFIG_SYSFS=y, otherwise
only a dummy variant is present. In the unlikely case that the kernel is
configured with CONFIG_MODULES=y and CONFIG_SYSFS=n, this results in
a memory leak of charp values when a module is unloaded.

Fix this issue by making destroy_params() always available when
CONFIG_MODULES=y. Rename the function to module_destroy_params() to clarify
that it is intended for use by the module loader.

Fixes: e180a6b7759a ("param: fix charp parameters set via sysfs")
Signed-off-by: Petr Pavlu 
Signed-off-by: Sami Tolvanen 
Signed-off-by: Sasha Levin

params: Replace modinit with init_or_module

2026-05-23T11:06:26+00:00

[ Upstream commit 3cb0c3bdea5388519bc1bf575dca6421b133302b ]

Remove the custom __modinit macro from kernel/params.c and instead use the
common __init_or_module macro from include/linux/module.h. Both provide the
same functionality.

Signed-off-by: Petr Pavlu 
Reviewed-by: Aaron Tomlin 
Reviewed-by: Daniel Gomez 
Reviewed-by: Sami Tolvanen 
Signed-off-by: Sami Tolvanen 
Stable-dep-of: deffe1edba62 ("module: Fix freeing of charp module parameters when CONFIG_SYSFS=n")
Signed-off-by: Sasha Levin

params: Replace deprecated strcpy() with strscpy() and memcpy()

2025-08-16T19:47:25+00:00

strcpy() is deprecated; use strscpy() and memcpy() instead.

In param_set_copystring(), we can safely use memcpy() because we already
know the length of the source string 'val' and that it is guaranteed to
be NUL-terminated within the first 'kps->maxlen' bytes.

Link: https://github.com/KSPP/linux/issues/88
Signed-off-by: Thorsten Blum 
Reviewed-by: Daniel Gomez 
Reviewed-by: Petr Pavlu 
Link: https://lore.kernel.org/r/20250813132200.184064-2-thorsten.blum@linux.dev
Signed-off-by: Daniel Gomez

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

2025-05-07T18:24:59+00:00

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

kernel: globalize lookup_or_create_module_kobject()

2025-04-16T12:54:53+00:00

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

kernel: refactor lookup_or_create_module_kobject()

2025-04-16T12:54:35+00:00

In the unlikely event of the allocation failing, it is better to let
the machine boot with a not fully populated sysfs than to kill it with
this BUG_ON(). All callers are already prepared for
lookup_or_create_module_kobject() returning NULL.

This is also preparation for calling this function from non __init
code, where using BUG_ON for allocation failure handling is not
acceptable.

Since we are here, also start using IS_ENABLED instead of #ifdef
construct.

Suggested-by: Thomas Weißschuh 
Suggested-by: Rasmus Villemoes 
Signed-off-by: Shyam Saini 
Link: https://lore.kernel.org/r/20250227184930.34163-3-shyamsaini@linux.microsoft.com
Signed-off-by: Petr Pavlu

kernel: param: rename locate_module_kobject

2025-04-16T12:35:46+00:00

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

params: Annotate struct module_param_attrs with __counted_by()

2025-03-10T10:54:46+00:00

Add the __counted_by compiler attribute to the flexible array member
attrs to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.

Increment num before adding a new param_attribute to the attrs array and
adjust the array index accordingly. Increment num immediately after the
first reallocation such that the reallocation for the NULL terminator
only needs to add 1 (instead of 2) to mk->mp->num.

Use struct_size() instead of manually calculating the size for the
reallocation.

Use krealloc_array() for the additional NULL terminator.

Cc: Andy Shevchenko 
Cc: Luis Chamberlain 
Cc: Nathan Chancellor 
Signed-off-by: Thorsten Blum 
Reviewed-by: Luis Chamberlain 
Link: https://lore.kernel.org/r/20250213221352.2625-3-thorsten.blum@linux.dev
Signed-off-by: Petr Pavlu

module: Constify 'struct module_attribute'

2025-01-26T12:05:23+00:00

These structs are never modified, move them to read-only memory.
This makes the API clearer and also prepares for the constification of
'struct attribute' itself.

While at it, also constify 'modinfo_attrs_count'.

Signed-off-by: Thomas Weißschuh 
Reviewed-by: Petr Pavlu 
Link: https://lore.kernel.org/r/20241216-sysfs-const-attr-module-v1-3-3790b53e0abf@weissschuh.net
Signed-off-by: Petr Pavlu

module: Handle 'struct module_version_attribute' as const