* Re: [Qemu-devel] [PATCH] xen-block: stop leaking memory in xen_block_drive_create()
[not found] <20190219163440.15702-1-paul.durrant@citrix.com>
@ 2019-02-19 16:36 ` Paul Durrant
2019-02-25 16:46 ` Anthony PERARD
2019-02-19 16:37 ` Peter Maydell
1 sibling, 1 reply; 3+ messages in thread
From: Paul Durrant @ 2019-02-19 16:36 UTC (permalink / raw)
To: qemu-block@nongnu.org, xen-devel@lists.xenproject.org,
qemu-devel@nongnu.org
Cc: Peter Maydell, Stefano Stabellini, Anthony Perard, Kevin Wolf,
Max Reitz
Apologies... typo-ed qemu-devel...
> -----Original Message-----
> From: Paul Durrant [mailto:paul.durrant@citrix.com]
> Sent: 19 February 2019 16:35
> To: qeme-devel@nongnu.org; qemu-block@nongnu.org; xen-
> devel@lists.xenproject.org
> Cc: Paul Durrant <Paul.Durrant@citrix.com>; Peter Maydell
> <peter.maydell@linaro.org>; Stefano Stabellini <sstabellini@kernel.org>;
> Anthony Perard <anthony.perard@citrix.com>; Kevin Wolf <kwolf@redhat.com>;
> Max Reitz <mreitz@redhat.com>
> Subject: [PATCH] xen-block: stop leaking memory in
> xen_block_drive_create()
>
> The locally allocated QDict-s need to be freed. ('file_layer' will be
> freed implicitly since it is added as an object to 'driver_layer').
>
> Spotted by Coverity: CID 1398649
>
> While in the neighbourhood free 'driver' and 'filename' as soon as they
> are
> added to the QDicts. Freeing after the 'done' label doesn't make that much
> sense as, if the error path jumps to that label, the values would be NULL
> anyway.
>
> This patch also makes that more obvious by taking the error path if
> 'params' is NULL and then asserting that both driver and filename are
> non-NULL in the normal path.
>
> Reported-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
> ---
> Cc: Stefano Stabellini <sstabellini@kernel.org>
> Cc: Anthony Perard <anthony.perard@citrix.com>
> Cc: Kevin Wolf <kwolf@redhat.com>
> Cc: Max Reitz <mreitz@redhat.com>
> ---
> hw/block/xen-block.c | 16 +++++++++-------
> 1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
> index 37a456c207..70fc2455e8 100644
> --- a/hw/block/xen-block.c
> +++ b/hw/block/xen-block.c
> @@ -743,12 +743,12 @@ static XenBlockDrive *xen_block_drive_create(const
> char *id,
> }
>
> g_strfreev(v);
> - }
> -
> - if (!filename) {
> - error_setg(errp, "no filename");
> + } else {
> + error_setg(errp, "no params");
> goto done;
> }
> +
> + assert(filename);
> assert(driver);
>
> drive = g_new0(XenBlockDrive, 1);
> @@ -758,6 +758,7 @@ static XenBlockDrive *xen_block_drive_create(const
> char *id,
>
> qdict_put_str(file_layer, "driver", "file");
> qdict_put_str(file_layer, "filename", filename);
> + g_free(filename);
>
> if (mode && *mode != 'w') {
> qdict_put_bool(file_layer, "read-only", true);
> @@ -793,16 +794,17 @@ static XenBlockDrive *xen_block_drive_create(const
> char *id,
> driver_layer = qdict_new();
>
> qdict_put_str(driver_layer, "driver", driver);
> + g_free(driver);
> +
> qdict_put_obj(driver_layer, "file", QOBJECT(file_layer));
>
> g_assert(!drive->node_name);
> drive->node_name = xen_block_blockdev_add(drive->id, driver_layer,
> &local_err);
>
> -done:
> - g_free(driver);
> - g_free(filename);
> + qobject_unref(driver_layer);
>
> +done:
> if (local_err) {
> error_propagate(errp, local_err);
> xen_block_drive_destroy(drive, NULL);
> --
> 2.20.1.2.gb21ebb6
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [Qemu-devel] [PATCH] xen-block: stop leaking memory in xen_block_drive_create()
[not found] <20190219163440.15702-1-paul.durrant@citrix.com>
2019-02-19 16:36 ` [Qemu-devel] [PATCH] xen-block: stop leaking memory in xen_block_drive_create() Paul Durrant
@ 2019-02-19 16:37 ` Peter Maydell
1 sibling, 0 replies; 3+ messages in thread
From: Peter Maydell @ 2019-02-19 16:37 UTC (permalink / raw)
To: Paul Durrant, QEMU Developers
Cc: Qemu-block, open list:X86, Stefano Stabellini, Anthony Perard,
Kevin Wolf, Max Reitz
Hi Paul -- you typoed the qemu-devel list email address; cc'd the right one.
thanks
-- PMM
On Tue, 19 Feb 2019 at 16:35, Paul Durrant <paul.durrant@citrix.com> wrote:
>
> The locally allocated QDict-s need to be freed. ('file_layer' will be
> freed implicitly since it is added as an object to 'driver_layer').
>
> Spotted by Coverity: CID 1398649
>
> While in the neighbourhood free 'driver' and 'filename' as soon as they are
> added to the QDicts. Freeing after the 'done' label doesn't make that much
> sense as, if the error path jumps to that label, the values would be NULL
> anyway.
>
> This patch also makes that more obvious by taking the error path if
> 'params' is NULL and then asserting that both driver and filename are
> non-NULL in the normal path.
>
> Reported-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
> ---
> Cc: Stefano Stabellini <sstabellini@kernel.org>
> Cc: Anthony Perard <anthony.perard@citrix.com>
> Cc: Kevin Wolf <kwolf@redhat.com>
> Cc: Max Reitz <mreitz@redhat.com>
> ---
> hw/block/xen-block.c | 16 +++++++++-------
> 1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
> index 37a456c207..70fc2455e8 100644
> --- a/hw/block/xen-block.c
> +++ b/hw/block/xen-block.c
> @@ -743,12 +743,12 @@ static XenBlockDrive *xen_block_drive_create(const char *id,
> }
>
> g_strfreev(v);
> - }
> -
> - if (!filename) {
> - error_setg(errp, "no filename");
> + } else {
> + error_setg(errp, "no params");
> goto done;
> }
> +
> + assert(filename);
> assert(driver);
>
> drive = g_new0(XenBlockDrive, 1);
> @@ -758,6 +758,7 @@ static XenBlockDrive *xen_block_drive_create(const char *id,
>
> qdict_put_str(file_layer, "driver", "file");
> qdict_put_str(file_layer, "filename", filename);
> + g_free(filename);
>
> if (mode && *mode != 'w') {
> qdict_put_bool(file_layer, "read-only", true);
> @@ -793,16 +794,17 @@ static XenBlockDrive *xen_block_drive_create(const char *id,
> driver_layer = qdict_new();
>
> qdict_put_str(driver_layer, "driver", driver);
> + g_free(driver);
> +
> qdict_put_obj(driver_layer, "file", QOBJECT(file_layer));
>
> g_assert(!drive->node_name);
> drive->node_name = xen_block_blockdev_add(drive->id, driver_layer,
> &local_err);
>
> -done:
> - g_free(driver);
> - g_free(filename);
> + qobject_unref(driver_layer);
>
> +done:
> if (local_err) {
> error_propagate(errp, local_err);
> xen_block_drive_destroy(drive, NULL);
> --
> 2.20.1.2.gb21ebb6
^ permalink raw reply [flat|nested] 3+ messages in thread