Re: [PATCH] module: fix lost error code from codetag_load_module()

[Bradley Morgan]

On 26 August 2026 10:24:03 BST, Petr Pavlu <petr.pavlu@xxxxxxxx> wrote:
>On 8/24/26 3:47 AM, Hao Ge wrote:
>> If codetag_load_module() fails, err is never set and load_module()
>> returns 0 after the module has been torn down.
>> 
>> Fixes: 044d2aee6c57 ("alloc_tag: handle module codetag load errors as
>module load failures")
>> Reported-by: Sashiko <sashiko-bot@xxxxxxxxxx>
>> Cc: stable@xxxxxxxxxxxxxxx
>> Signed-off-by: Hao Ge <hao.ge@xxxxxxxxx>
>> ---
>>  kernel/module/main.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>> 
>> diff --git a/kernel/module/main.c b/kernel/module/main.c
>> index 46dd8d25a605..afb810f0154c 100644
>> --- a/kernel/module/main.c
>> +++ b/kernel/module/main.c
>> @@ -3568,7 +3568,8 @@ static int load_module(struct load_info *info,
>const char __user *uargs,
>>  			goto sysfs_cleanup;
>>  	}
>>  
>> -	if (codetag_load_module(mod))
>> +	err = codetag_load_module(mod);
>> +	if (err)
>>  		goto sysfs_cleanup;
>>  
>>  	/* Get rid of temporary copy. */
>
>This looks ok to me but there appears another bug related to this code
>that would be good to fix at the same time. If the module is
>a livepatch, the preceding call to copy_module_elf() allocates
>mod->klp_info. However, if codetag_load_module() fails, the code doesn't
>free it.
>
>I think we want something like this (not tested):
>
>diff --git a/kernel/module/main.c b/kernel/module/main.c
>index d0e1e0bd2ad0..c1b34dc1e89a 100644
>--- a/kernel/module/main.c
>+++ b/kernel/module/main.c
>@@ -3581,8 +3581,9 @@ static int load_module(struct load_info *info, const char __user *uargs,
> 			goto sysfs_cleanup;
> 	}
> 
>-	if (codetag_load_module(mod))
>-		goto sysfs_cleanup;
>+	err = codetag_load_module(mod);
>+	if (err)
>+		goto livepatch_cleanup;
> 
> 	/* Get rid of temporary copy. */
> 	free_copy(info, flags);
>@@ -3592,6 +3593,9 @@ static int load_module(struct load_info *info, const char __user *uargs,
> 
> 	return do_init_module(mod);
> 
>+ livepatch_cleanup:
>+	if (is_livepatch_module(mod))
>+		free_module_elf(mod);
>  sysfs_cleanup:
> 	mod_sysfs_teardown(mod);
>  coming_cleanup:
>
>

If patch is submitted!

Reviewed-by: Bradley Morgan <brads@xxxxxxxxxxxxxx>

--- Thanks!
https://lore.kernel.org/all/EE579805-42F2-4C58-B752-F28779EEB717@xxxxxxxxx/