[PATCH 05/19] qemuMigrationSrcPerformPeer2Peer3: Don't leak 'dom_xml' on cleanup

[Jiri Denemark]

On Thu, Feb 11, 2021 at 16:37:44 +0100, Peter Krempa wrote:
> Use g_autofree for 'dom_xml' to free it on some of the (unlikely) code
> paths jumping to cleanup prior to the deallocation which is done right
> after it's not needed any more since it's a big string.
> 
> Noticed when running under valgrind:
> 
> ==2204780== 8,192 bytes in 1 blocks are definitely lost in loss record 2,539 of 2,551
> ==2204780==    at 0x483BCE8: realloc (vg_replace_malloc.c:834)
> ==2204780==    by 0x4D890DF: g_realloc (in /usr/lib64/libglib-2.0.so.0.6600.4)
> ==2204780==    by 0x4DA3AF0: g_string_append_vprintf (in /usr/lib64/libglib-2.0.so.0.6600.4)
> ==2204780==    by 0x4917293: virBufferAsprintf (virbuffer.c:307)
> ==2204780==    by 0x49B0B75: virDomainChrDefFormat (domain_conf.c:26109)
> ==2204780==    by 0x49E25EF: virDomainDefFormatInternalSetRootName (domain_conf.c:28956)
> ==2204780==    by 0x15F81D24: qemuDomainDefFormatBufInternal (qemu_domain.c:6204)
> ==2204780==    by 0x15F8270D: qemuDomainDefFormatXMLInternal (qemu_domain.c:6229)
> ==2204780==    by 0x15F8270D: qemuDomainDefFormatLive (qemu_domain.c:6279)
> ==2204780==    by 0x15FD8100: qemuMigrationSrcBeginPhase (qemu_migration.c:2395)
> ==2204780==    by 0x15FE0F0D: qemuMigrationSrcPerformPeer2Peer3 (qemu_migration.c:4640)
> ==2204780==    by 0x15FE0F0D: qemuMigrationSrcPerformPeer2Peer (qemu_migration.c:5093)
> ==2204780==    by 0x15FE0F0D: qemuMigrationSrcPerformJob (qemu_migration.c:5168)
> ==2204780==    by 0x15FE280E: qemuMigrationSrcPerform (qemu_migration.c:5372)
> ==2204780==    by 0x15F9BA3D: qemuDomainMigratePerform3Params (qemu_driver.c:11841)
> 
> Signed-off-by: Peter Krempa <pkrempa at redhat.com>
> ---
>  src/qemu/qemu_migration.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
> index f44d31c971..37f0d43d24 100644
> --- a/src/qemu/qemu_migration.c
> +++ b/src/qemu/qemu_migration.c
> @@ -4347,7 +4347,7 @@ qemuMigrationSrcPerformPeer2Peer3(virQEMUDriverPtr driver,
>      char *uri_out = NULL;
>      char *cookiein = NULL;
>      char *cookieout = NULL;
> -    char *dom_xml = NULL;
> +    g_autofree char *dom_xml = NULL;
>      int cookieinlen = 0;
>      int cookieoutlen = 0;
>      int ret = -1;

Oh wow, the leak has been with us for 10 years since v3 migration
protocol was introduced...

Reviewed-by: Jiri Denemark <jdenemar at redhat.com>