[Devel] [PATCH vz10] modules: use kvmalloc for the section attribute pointer array too

[Pavel Tikhomirov]

Reviewed-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>

On 6/11/26 22:42, Konstantin Khorenko wrote:
> The patch switched the struct module_sect_attrs allocation in
> add_sect_attrs() to kvzalloc() so a module with many ELF sections
> does not need a high-order allocation.
> 
> The RHEL10.2 base carries upstream f47c0bebed44 ("module: sysfs:
> Simplify section attribute allocation"), which split the bin_attribute
> pointer array out of that struct into its own allocation:
> 
> 	gattr = kcalloc(nloaded + 1, sizeof(*gattr), GFP_KERNEL);
> 
> For a module with many sections this is another nloaded-sized array
> that can cross a page and require a high-order allocation - exactly
> what the patch set out to avoid. Allocate it with kvcalloc() and free
> it with kvfree() in free_sect_attrs().
> 
> Fixes: 8b230b0af770 ("modules: use kvmalloc when creating sysfs attributes for ELF sections")
> 
> Reported-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
> https://virtuozzo.atlassian.net/browse/VSTOR-132310
> Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
> ---
>  kernel/module/sysfs.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/module/sysfs.c b/kernel/module/sysfs.c
> index a896022e6186..4d0286559123 100644
> --- a/kernel/module/sysfs.c
> +++ b/kernel/module/sysfs.c
> @@ -59,7 +59,7 @@ static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
>  
>  	for (bin_attr = sect_attrs->grp.bin_attrs_new; *bin_attr; bin_attr++)
>  		kfree((*bin_attr)->attr.name);
> -	kfree(sect_attrs->grp.bin_attrs_new);
> +	kvfree(sect_attrs->grp.bin_attrs_new);
>  	kvfree(sect_attrs);
>  }
>  
> @@ -79,7 +79,7 @@ static int add_sect_attrs(struct module *mod, const struct load_info *info)
>  	if (!sect_attrs)
>  		return -ENOMEM;
>  
> -	gattr = kcalloc(nloaded + 1, sizeof(*gattr), GFP_KERNEL);
> +	gattr = kvcalloc(nloaded + 1, sizeof(*gattr), GFP_KERNEL);
>  	if (!gattr) {
>  		kvfree(sect_attrs);
>  		return -ENOMEM;

-- 
Best regards, Pavel Tikhomirov
Senior Software Developer, Virtuozzo.