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

In 'lookup_or_create_module_kobject()', an internal kobject is created
using 'module_ktype'. So call to 'kobject_put()' on error ha

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

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: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=7fb8a372e1f6add936dd
Fixes: 942e443127e9 ("module: Fix mod->mkobj.kobj potentially freed too early")
Cc: [email protected]
Suggested-by: Petr Pavlu <[email protected]>
Signed-off-by: Dmitry Antipov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Pavlu <[email protected]>

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kernel: globalize lookup_or_create_module_kobject()

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 no

kernel: globalize lookup_or_create_module_kobject()

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 <[email protected]>
Signed-off-by: Shyam Saini <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Pavlu <[email protected]>

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kernel: refactor lookup_or_create_module_kobject()

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 BU

kernel: refactor lookup_or_create_module_kobject()

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 <[email protected]>
Suggested-by: Rasmus Villemoes <[email protected]>
Signed-off-by: Shyam Saini <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Pavlu <[email protected]>

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kernel: param: rename locate_module_kobject

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 c

kernel: param: rename locate_module_kobject

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 <[email protected]>
Signed-off-by: Shyam Saini <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Pavlu <[email protected]>

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params: Annotate struct module_param_attrs with __counted_by()

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

params: Annotate struct module_param_attrs with __counted_by()

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 <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Signed-off-by: Thorsten Blum <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Petr Pavlu <[email protected]>

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module: Constify 'struct module_attribute'

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'

module: Constify 'struct module_attribute'

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 <[email protected]>
Reviewed-by: Petr Pavlu <[email protected]>
Link: https://lore.kernel.org/r/20241216-sysfs-const-attr-module-v1-3-3790b53e0abf@weissschuh.net
Signed-off-by: Petr Pavlu <[email protected]>

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module: Handle 'struct module_version_attribute' as const

The structure is always read-only due to its placement in the read-only
section __modver. Reflect this at its usage sites.
Also prepare for

module: Handle 'struct module_version_attribute' as const

The structure is always read-only due to its placement in the read-only
section __modver. Reflect this at its usage sites.
Also prepare for the const handling of 'struct module_attribute' itself.

Signed-off-by: Thomas Weißschuh <[email protected]>
Reviewed-by: Petr Pavlu <[email protected]>
Link: https://lore.kernel.org/r/20241216-sysfs-const-attr-module-v1-2-3790b53e0abf@weissschuh.net
Signed-off-by: Petr Pavlu <[email protected]>

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params: Prepare for 'const struct module_attribute *'

The 'struct module_attribute' sysfs callbacks are about to change to
receive a 'const struct module_attribute *' parameter.
Prepare for that by

params: Prepare for 'const struct module_attribute *'

The 'struct module_attribute' sysfs callbacks are about to change to
receive a 'const struct module_attribute *' parameter.
Prepare for that by avoid casting away the constness through
container_of() and using const pointers to 'struct param_attribute'.

Signed-off-by: Thomas Weißschuh <[email protected]>
Reviewed-by: Petr Pavlu <[email protected]>
Link: https://lore.kernel.org/r/20241216-sysfs-const-attr-module-v1-1-3790b53e0abf@weissschuh.net
Signed-off-by: Petr Pavlu <[email protected]>

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params: Fix multi-line comment style

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

Reviewed-by: Luis Chamberlain <[email protected]>
Reviewed-by: Ke

params: Fix multi-line comment style

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

Reviewed-by: Luis Chamberlain <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>

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params: Sort headers

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

Reviewed-by: Luis Chamberlain <[email protected]>
Reviewed-by: Kees Cook <keescook@chromium

params: Sort headers

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

Reviewed-by: Luis Chamberlain <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>

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params: Use size_add() for kmalloc()

Prevent allocations from integer overflow by using size_add().

Reviewed-by: Luis Chamberlain <[email protected]>
Reviewed-by: Kees Cook <[email protected]>

params: Use size_add() for kmalloc()

Prevent allocations from integer overflow by using size_add().

Reviewed-by: Luis Chamberlain <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>

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

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

Review

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

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 <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>

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params: Introduce the param_unknown_fn type

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 C

params: Introduce the param_unknown_fn type

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 <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>

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

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

Signed-off-by: Li zeming <[email protected]>
Reviewed-by: Randy Dun

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

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

Signed-off-by: Li zeming <[email protected]>
Reviewed-by: Randy Dunlap <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

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kallsyms: Replace all non-returning strlcpy with strscpy

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to lin

kallsyms: Replace all non-returning strlcpy with strscpy

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 <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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module: make module_ktype structure constant

Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.

Take advantage of this t

module: make module_ktype structure constant

Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.

Take advantage of this to constify the structure definition to prevent
modification at runtime.

Signed-off-by: Thomas Weißschuh <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

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kernel/params.c: Use kstrtobool() instead of strtobool()

strtobool() is the same as kstrtobool().
However, the latter is more used within the kernel.

In order to remove strtobool() and slightly sim

kernel/params.c: Use kstrtobool() instead of strtobool()

strtobool() is the same as kstrtobool().
However, the latter is more used within the kernel.

In order to remove strtobool() and slightly simplify kstrtox.h, switch to
the other function name.

While at it, include the corresponding header file (<linux/kstrtox.h>)

Signed-off-by: Christophe JAILLET <[email protected]>
Reviewed-by: Miroslav Benes <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

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kobject: kset_uevent_ops: make filter() callback take a const *

The filter() callback in struct kset_uevent_ops does not modify the
kobject passed into it, so make the pointer const to enforce this

kobject: kset_uevent_ops: make filter() callback take a const *

The filter() callback in struct kset_uevent_ops does not modify the
kobject passed into it, so make the pointer const to enforce this
restriction. When doing so, fix up all existing filter() callbacks to
have the correct signature to preserve the build.

Cc: Sumit Semwal <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Acked-by: Rafael J. Wysocki <[email protected]>
Acked-by: Christian König <[email protected]> for the changes to
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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kernel/params.c: defer most of param_sysfs_init() to late_initcall time

param_sysfs_init(), and in particular param_sysfs_builtin() is rather
time-consuming; for my board, it currently takes about 3

kernel/params.c: defer most of param_sysfs_init() to late_initcall time

param_sysfs_init(), and in particular param_sysfs_builtin() is rather
time-consuming; for my board, it currently takes about 30ms.

That amounts to about 3% of the time budget I have from U-Boot hands
over control to linux and linux must assume responsibility for keeping
the external watchdog happy.

We must still continue to initialize module_kset at subsys_initcall
time, since otherwise any request_module() would fail in
mod_sysfs_init(). However, the bulk of the work in
param_sysfs_builtin(), namely populating /sys/module/*/version and/or
/sys/module/*/parameters/ for builtin modules, can be deferred to
late_initcall time - there's no userspace yet anyway to observe
contents of /sys or the lack thereof.

Signed-off-by: Rasmus Villemoes <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

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module: remove redundant module_sysfs_initialized variable

The variable module_sysfs_initialized is used for checking whether
module_kset has been initialized. Checking module_kset itself works
just

module: remove redundant module_sysfs_initialized variable

The variable module_sysfs_initialized is used for checking whether
module_kset has been initialized. Checking module_kset itself works
just fine for that.

This is a leftover from commit 7405c1e15edf ("kset: convert /sys/module
to use kset_create").

Signed-off-by: Rasmus Villemoes <[email protected]>
Reviewed-by: Miroslav Benes <[email protected]>
[mcgrof: adjusted commit log as suggested by Christophe Leroy]
Signed-off-by: Luis Chamberlain <[email protected]>

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kobject: remove kset from struct kset_uevent_ops callbacks

There is no need to pass the pointer to the kset in the struct
kset_uevent_ops callbacks as no one uses it, so just remove that pointer
ent

kobject: remove kset from struct kset_uevent_ops callbacks

There is no need to pass the pointer to the kset in the struct
kset_uevent_ops callbacks as no one uses it, so just remove that pointer
entirely.

Reviewed-by: Rafael J. Wysocki <[email protected]>
Reviewed-by: Wedson Almeida Filho <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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driver core: make kobj_type constant.

This way instances of kobj_type (which contain function pointers) can be
stored in .rodata, which means that they cannot be [easily/accidentally]
modified at ru

driver core: make kobj_type constant.

This way instances of kobj_type (which contain function pointers) can be
stored in .rodata, which means that they cannot be [easily/accidentally]
modified at runtime.

Signed-off-by: Wedson Almeida Filho <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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params: lift param_set_uint_minmax to common code

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

Suggested-by: Christoph Hellwig <[email protected]>
Reviewed-by: Chaitanya Kulk

params: lift param_set_uint_minmax to common code

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

Suggested-by: Christoph Hellwig <[email protected]>
Reviewed-by: Chaitanya Kulkarni <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Signed-off-by: Sagi Grimberg <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>

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module: simplify version-attribute handling

Instead of using the array-of-pointers trick to avoid having gcc mess up
the built-in module-version array stride, specify type alignment when
declaring e

module: simplify version-attribute handling

Instead of using the array-of-pointers trick to avoid having gcc mess up
the built-in module-version array stride, specify type alignment when
declaring entries to prevent gcc from increasing alignment.

This is essentially an alternative (one-line) fix to the problem
addressed by commit b4bc842802db ("module: deal with alignment issues in
built-in module versions").

gcc can increase the alignment of larger objects with static extent as
an optimisation, but this can be suppressed by using the aligned
attribute when declaring variables.

Note that we have been relying on this behaviour for kernel parameters
for 16 years and it indeed hasn't changed since the introduction of the
aligned attribute in gcc-3.1.

Link: https://lore.kernel.org/lkml/[email protected]
Signed-off-by: Johan Hovold <[email protected]>
Signed-off-by: Jessica Yu <[email protected]>

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

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. Ker

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

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 <[email protected]>

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