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

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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: e180a6b775 ("param: fix charp parameters set via sysfs")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

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Petr Pavlu 2026-03-13 14:48:02 +01:00 • committed by Sami Tolvanen

parent 4afc71bba8

commit deffe1edba

3 changed files with 23 additions and 19 deletions

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11

include/linux/moduleparam.h

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4

kernel/module/main.c

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27

kernel/params.c

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