[PATCH v2] pc: fix leak in pc_system_flash_cleanup_unused

[PATCH v2] pc: fix leak in pc_system_flash_cleanup_unused

[Alexander Bulekov]

tries to fix a leak detected when building with --enable-sanitizers:
./i386-softmmu/qemu-system-i386
Upon exit:
==13576==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 1216 byte(s) in 1 object(s) allocated from:
    #0 0x7f9d2ed5c628 in malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5)
    #1 0x7f9d2e963500 in g_malloc (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.)
    #2 0x55fa646d25cc in object_new_with_type /tmp/qemu/qom/object.c:686
    #3 0x55fa63dbaa88 in qdev_new /tmp/qemu/hw/core/qdev.c:140
    #4 0x55fa638a533f in pc_pflash_create /tmp/qemu/hw/i386/pc_sysfw.c:88
    #5 0x55fa638a54c4 in pc_system_flash_create /tmp/qemu/hw/i386/pc_sysfw.c:106
    #6 0x55fa646caa1d in object_init_with_type /tmp/qemu/qom/object.c:369
    #7 0x55fa646d20b5 in object_initialize_with_type /tmp/qemu/qom/object.c:511
    #8 0x55fa646d2606 in object_new_with_type /tmp/qemu/qom/object.c:687
    #9 0x55fa639431e9 in qemu_init /tmp/qemu/softmmu/vl.c:3878
    #10 0x55fa6335c1b8 in main /tmp/qemu/softmmu/main.c:48
    #11 0x7f9d2cf06e0a in __libc_start_main ../csu/libc-start.c:308
    #12 0x55fa6335f8e9 in _start (/tmp/qemu/build/i386-softmmu/qemu-system-i386)

Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
---
v2: move unref to pc_pflash_create, per Paolo's suggestion

 hw/i386/pc_sysfw.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
index ec2a3b3e7e..60a83c53ab 100644
--- a/hw/i386/pc_sysfw.c
+++ b/hw/i386/pc_sysfw.c
@@ -93,6 +93,7 @@ static PFlashCFI01 *pc_pflash_create(PCMachineState *pcms,
     object_property_add_child(OBJECT(pcms), name, OBJECT(dev));
     object_property_add_alias(OBJECT(pcms), alias_prop_name,
                               OBJECT(dev), "drive");
+    object_unref(OBJECT(dev));
     return PFLASH_CFI01(dev);
 }
 
-- 
2.26.2

Re: [PATCH v2] pc: fix leak in pc_system_flash_cleanup_unused

[Paolo Bonzini]

On 01/07/20 16:52, Alexander Bulekov wrote:
> tries to fix a leak detected when building with --enable-sanitizers:
> ./i386-softmmu/qemu-system-i386
> Upon exit:
> ==13576==ERROR: LeakSanitizer: detected memory leaks
> 
> Direct leak of 1216 byte(s) in 1 object(s) allocated from:
>     #0 0x7f9d2ed5c628 in malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5)
>     #1 0x7f9d2e963500 in g_malloc (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.)
>     #2 0x55fa646d25cc in object_new_with_type /tmp/qemu/qom/object.c:686
>     #3 0x55fa63dbaa88 in qdev_new /tmp/qemu/hw/core/qdev.c:140
>     #4 0x55fa638a533f in pc_pflash_create /tmp/qemu/hw/i386/pc_sysfw.c:88
>     #5 0x55fa638a54c4 in pc_system_flash_create /tmp/qemu/hw/i386/pc_sysfw.c:106
>     #6 0x55fa646caa1d in object_init_with_type /tmp/qemu/qom/object.c:369
>     #7 0x55fa646d20b5 in object_initialize_with_type /tmp/qemu/qom/object.c:511
>     #8 0x55fa646d2606 in object_new_with_type /tmp/qemu/qom/object.c:687
>     #9 0x55fa639431e9 in qemu_init /tmp/qemu/softmmu/vl.c:3878
>     #10 0x55fa6335c1b8 in main /tmp/qemu/softmmu/main.c:48
>     #11 0x7f9d2cf06e0a in __libc_start_main ../csu/libc-start.c:308
>     #12 0x55fa6335f8e9 in _start (/tmp/qemu/build/i386-softmmu/qemu-system-i386)
> 
> Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
> ---
> v2: move unref to pc_pflash_create, per Paolo's suggestion
> 
>  hw/i386/pc_sysfw.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
> index ec2a3b3e7e..60a83c53ab 100644
> --- a/hw/i386/pc_sysfw.c
> +++ b/hw/i386/pc_sysfw.c
> @@ -93,6 +93,7 @@ static PFlashCFI01 *pc_pflash_create(PCMachineState *pcms,
>      object_property_add_child(OBJECT(pcms), name, OBJECT(dev));
>      object_property_add_alias(OBJECT(pcms), alias_prop_name,
>                                OBJECT(dev), "drive");
> +    object_unref(OBJECT(dev));
>      return PFLASH_CFI01(dev);
>  }
>  
> 

Queued, with a small comment above.

Paolo