Re: [PATCH dwarves] dwarf_loader: Fix memleak in dwarf_cus__create_cu

[Viktor Malik <vmalik@redhat.com>]

On 9/2/24 15:16, Alan Maguire wrote:
> On 02/09/2024 12:11, Viktor Malik wrote:
>> Coverity reports a possible memleak in `dwarf_cus__create_cu` due to
>> `cu` not being freed for the case when it was allocated but
>> `cu__set_common` failed. Fix the leak.
>>
>> Signed-off-by: Viktor Malik <vmalik@redhat.com>
>> ---
>>  dwarf_loader.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/dwarf_loader.c b/dwarf_loader.c
>> index 04f5637..ad36e3c 100644
>> --- a/dwarf_loader.c
>> +++ b/dwarf_loader.c
>> @@ -3378,8 +3378,10 @@ static struct dwarf_cu *dwarf_cus__create_cu(struct dwarf_cus *dcus, Dwarf_Die *
>>  	 */
>>  	const char *name = attr_string(cu_die, DW_AT_name, dcus->conf);
>>  	struct cu *cu = cu__new(name ?: "", pointer_size, dcus->build_id, dcus->build_id_len, dcus->filename, dcus->conf->use_obstack);
>> -	if (cu == NULL || cu__set_common(cu, dcus->conf, dcus->mod, dcus->elf) != 0)
>> +	if (cu == NULL || cu__set_common(cu, dcus->conf, dcus->mod, dcus->elf) != 0) {
>> +		cu__delete(cu);
>>  		return NULL;
>> +	}
>>  
>>  	struct dwarf_cu *dcu = dwarf_cu__new(cu);
>>  
> 
> Good catch! Looks like there's another few instances of cu leaks like
> this later on in __cus__load_debug_types():
> 
> 
> 	if (*cup == NULL) {
>                         struct cu *cu;
> 
>                         cu = cu__new("", pointer_size, build_id,
>                                      build_id_len, filename,
> conf->use_obstack);
>                         if (cu == NULL ||
>                             cu__set_common(cu, conf, mod, elf) != 0) {
> need cu__delete() here ->
>                                 return DWARF_CB_ABORT;
>                         }
> 
>                         if (dwarf_cu__init(dcup, cu) != 0)
> need cu__delete() here ->
>                                 return DWARF_CB_ABORT;
> 
> 
> Could you respin to fix them too? Thanks!
> 

Sure, I'll check those and send v2 tomorrow.

Viktor