Re: [PATCH] powerpc/mpic: Fix memory leak of mpic on error paths

[jyoti <jyoti@linux.ibm.com>]

On 2026-09-24 14:58, Mukesh Kumar Chaurasiya wrote:
> On Thu, Sep 24, 2026 at 12:00:10PM +0530, Jyoti Gupta wrote:
>> mpic_alloc() allocates struct mpic (and optionally the protected
>> sources bitmap) but does not free them when mpic_setup_error_int() or
>> irq_domain_create_linear() fails, leaking the memory.
>> 
>> Initialise mpic to NULL and free the bitmap and the mpic in the common
>> error path before dropping the device node reference. The register
>> mappings are not released here.
>> 
>> Signed-off-by: Jyoti Gupta <jyoti@linux.ibm.com>
>> ---
>>  arch/powerpc/sysdev/mpic.c | 9 ++++-----
>>  1 file changed, 4 insertions(+), 5 deletions(-)
>> 
>> diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
>> index 6e8fa94985f3..e777b33f170d 100644
>> --- a/arch/powerpc/sysdev/mpic.c
>> +++ b/arch/powerpc/sysdev/mpic.c
>> @@ -1221,7 +1221,7 @@ struct mpic * __init mpic_alloc(struct 
>> device_node *node,
>>  				const char *name)
>>  {
>>  	int i, psize, intvec_top;
>> -	struct mpic *mpic;
>> +	struct mpic *mpic = NULL;
> We don't need this initialization. We initialize it later again.

Agree

>>  	u32 greg_feature;
>>  	const char *vers;
>>  	const u32 *psrc;
>> @@ -1488,10 +1488,6 @@ struct mpic * __init mpic_alloc(struct 
>> device_node *node,
>>  						 intvec_top,
>>  						 &mpic_host_ops, mpic);
>> 
>> -	/*
>> -	 * FIXME: The code leaks the MPIC object and mappings here; this
>> -	 * is very unlikely to fail but it ought to be fixed anyways.
>> -	 */
>>  	if (mpic->irqhost == NULL)
>>  		goto err_of_node_put;
>> 
>> @@ -1527,6 +1523,9 @@ struct mpic * __init mpic_alloc(struct 
>> device_node *node,
>>  	return mpic;
>> 
>>  err_of_node_put:
>> +	if (mpic)
>> +		bitmap_free(mpic->protected);
>> +	kfree(mpic);
>>  	of_node_put(node);
>>  	return NULL;
>>  }
>> --
>> 2.55.0
>> 
>> 
> Do we need a fixes tag for this?
> 
Agree


Thanks,
Jyoti