[Qemu-devel] [PATCH][STABLE] block: Free iovec arrays allocated by multiwrite_merge()

[Qemu-devel] [PATCH][STABLE] block: Free iovec arrays allocated by multiwrite_merge()

[Stefan Hajnoczi]

A new iovec array is allocated when creating a merged write request.
This patch ensures that the iovec array is deleted in addition to its
qiov owner.

Reported-by: Leszek Urbanski <tygrys@moo.pl>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---

This fixes the virtio-blk memory leak that has recently been reported by Leszek
Urbanski <tygrys@moo.pl>.

The patch should apply to qemu.git and qemu-kvm.git.  I'm proposing this patch
for both qemu and qemu-kvm and their stable branches.  Sorry if the CCs are
overkill, please let me know so I can follow the process better next time.

 block.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/block.c b/block.c
index 0881c93..99dd0f3 100644
--- a/block.c
+++ b/block.c
@@ -1731,6 +1731,9 @@ static void multiwrite_user_cb(MultiwriteCB *mcb)
 
     for (i = 0; i < mcb->num_callbacks; i++) {
         mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
+        if (mcb->callbacks[i].free_qiov) {
+            qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
+        }
         qemu_free(mcb->callbacks[i].free_qiov);
         qemu_vfree(mcb->callbacks[i].free_buf);
     }
-- 
1.7.0

Re: [Qemu-devel] [PATCH][STABLE] block: Free iovec arrays allocated by multiwrite_merge()

[Kevin Wolf]

Am 21.04.2010 21:35, schrieb Stefan Hajnoczi:
> A new iovec array is allocated when creating a merged write request.
> This patch ensures that the iovec array is deleted in addition to its
> qiov owner.
> 
> Reported-by: Leszek Urbanski <tygrys@moo.pl>
> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Acked-by: Kevin Wolf <kwolf@redhat.com>

Picked it up for my block branch, too, but I think this should be
committed immediately by Aurelien.

Kevin