Re: [PATCH-for-5.1 4/4] hw/avr/boot: Fix memory leak in avr_load_firmware()

[Daniel P . Berrangé]

On Tue, Jul 14, 2020 at 06:42:57PM +0200, Philippe Mathieu-Daudé wrote:
> The value returned by qemu_find_file() must be freed.
> 
> This fixes Coverity issue CID 1430449, which points out
> that the memory returned by qemu_find_file() is leaked.
> 
> Fixes: Coverity CID 1430449 (RESOURCE_LEAK)
> Fixes: 7dd8f6fde4 ('hw/avr: Add support for loading ELF/raw binaries')
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  hw/avr/boot.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/avr/boot.c b/hw/avr/boot.c
> index 6fbcde4061..151734f82d 100644
> --- a/hw/avr/boot.c
> +++ b/hw/avr/boot.c
> @@ -60,7 +60,7 @@ static const char *avr_elf_e_flags_to_cpu_type(uint32_t 
> flags)
>  bool avr_load_firmware(AVRCPU *cpu, MachineState *ms,
>                         MemoryRegion *program_mr, const char *firmware)
>  {
> -    const char *filename;
> +    g_autofree char *filename;

Any variable marked g_autofree or g_auto must always be initialized
to NULL otherwise there's risk of free'ing uninitialized data. Even
if currently safe, any later refactoring could turn it into a bug.

So iff "= NULL" is added:

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>


Regards,
Daniel
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