[PATCH] module: procfs: fix signed integer overflow in module_total_size()

[PATCH] module: procfs: fix signed integer overflow in module_total_size()

[Naveen Kumar Chaudhary]

module_total_size() accumulates unsigned section sizes into a signed int
before returning as unsigned int. If the total exceeds INT_MAX, this is
signed integer overflow.

Change the accumulator to unsigned int to match the return type.

Signed-off-by: Naveen Kumar Chaudhary <naveen.osdev@gmail.com>
---
 kernel/module/procfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/module/procfs.c b/kernel/module/procfs.c
index 0a4841e88adb..90712aa9dd13 100644
--- a/kernel/module/procfs.c
+++ b/kernel/module/procfs.c
@@ -64,7 +64,7 @@ static void m_stop(struct seq_file *m, void *p)
 
 static unsigned int module_total_size(struct module *mod)
 {
-	int size = 0;
+	unsigned int size = 0;
 
 	for_each_mod_mem_type(type)
 		size += mod->mem[type].size;
-- 
2.43.0

Re: [PATCH] module: procfs: fix signed integer overflow in module_total_size()

[Sami Tolvanen]

On Wed, Jun 03, 2026 at 09:54:11PM +0530, Naveen Kumar Chaudhary wrote:
> module_total_size() accumulates unsigned section sizes into a signed int
> before returning as unsigned int. If the total exceeds INT_MAX, this is
> signed integer overflow.

This doesn't sound accurate to me. The compiler performs an implicit
type conversion, but there's no signed integer overflow:

https://godbolt.org/z/hzGrYMsPW

> Change the accumulator to unsigned int to match the return type.
> 
> Signed-off-by: Naveen Kumar Chaudhary <naveen.osdev@gmail.com>
> ---
>  kernel/module/procfs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/module/procfs.c b/kernel/module/procfs.c
> index 0a4841e88adb..90712aa9dd13 100644
> --- a/kernel/module/procfs.c
> +++ b/kernel/module/procfs.c
> @@ -64,7 +64,7 @@ static void m_stop(struct seq_file *m, void *p)
>  
>  static unsigned int module_total_size(struct module *mod)
>  {
> -	int size = 0;
> +	unsigned int size = 0;

While there's no behavioral difference, using unsigned int seems like
good hygiene. With the commit message corrected:

Reviewed-by: Sami Tolvanen <samitolvanen@google.com>

Sami