Messages in this thread | | | Date | Thu, 17 Aug 2023 15:03:25 +0100 | Subject | Re: [PATCH 1/2] coresight: Fix memory leak in acpi_buffer->pointer | From | James Clark <> |
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On 17/08/2023 09:59, Junhao He wrote: > There are memory leaks reported by kmemleak: > ... > unreferenced object 0xffff00213c141000 (size 1024): > comm "systemd-udevd", pid 2123, jiffies 4294909467 (age 6062.160s) > hex dump (first 32 bytes): > 04 00 00 00 02 00 00 00 18 10 14 3c 21 00 ff ff ...........<!... > 00 00 00 00 00 00 00 00 03 00 00 00 10 00 00 00 ................ > backtrace: > [<000000004b7c9001>] __kmem_cache_alloc_node+0x2f8/0x348 > [<00000000b0fc7ceb>] __kmalloc+0x58/0x108 > [<0000000064ff4695>] acpi_os_allocate+0x2c/0x68 > [<000000007d57d116>] acpi_ut_initialize_buffer+0x54/0xe0 > [<0000000024583908>] acpi_evaluate_object+0x388/0x438 > [<0000000017b2e72b>] acpi_evaluate_object_typed+0xe8/0x240 > [<000000005df0eac2>] coresight_get_platform_data+0x1b4/0x988 [coresight] > ... > > The ACPI buffer memory (buf.pointer) should be freed. But the buffer > is also used after returning from acpi_get_dsd_graph(). > Move the temporary variables buf to acpi_coresight_parse_graph(), > and free it before the function return to prevent memory leak. > > Fixes: 76ffa5ab5b79 ("coresight: Support for ACPI bindings") > Signed-off-by: Junhao He <hejunhao3@huawei.com>
I confirmed that the error gone. Thanks for the fix.
Reviewed-by: James Clark <james.clark@arm.com>
> --- > .../hwtracing/coresight/coresight-platform.c | 40 ++++++++++++------- > 1 file changed, 26 insertions(+), 14 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c > index 7d7b641c0a71..9d550f5697fa 100644 > --- a/drivers/hwtracing/coresight/coresight-platform.c > +++ b/drivers/hwtracing/coresight/coresight-platform.c > @@ -492,19 +492,18 @@ static inline bool acpi_validate_dsd_graph(const union acpi_object *graph) > > /* acpi_get_dsd_graph - Find the _DSD Graph property for the given device. */ > static const union acpi_object * > -acpi_get_dsd_graph(struct acpi_device *adev) > +acpi_get_dsd_graph(struct acpi_device *adev, struct acpi_buffer *buf) > { > int i; > - struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; > acpi_status status; > const union acpi_object *dsd; > > status = acpi_evaluate_object_typed(adev->handle, "_DSD", NULL, > - &buf, ACPI_TYPE_PACKAGE); > + buf, ACPI_TYPE_PACKAGE); > if (ACPI_FAILURE(status)) > return NULL; > > - dsd = buf.pointer; > + dsd = buf->pointer; > > /* > * _DSD property consists tuples { Prop_UUID, Package() } > @@ -555,12 +554,12 @@ acpi_validate_coresight_graph(const union acpi_object *cs_graph) > * returns NULL. > */ > static const union acpi_object * > -acpi_get_coresight_graph(struct acpi_device *adev) > +acpi_get_coresight_graph(struct acpi_device *adev, struct acpi_buffer *buf) > { > const union acpi_object *graph_list, *graph; > int i, nr_graphs; > > - graph_list = acpi_get_dsd_graph(adev); > + graph_list = acpi_get_dsd_graph(adev, buf); > if (!graph_list) > return graph_list; > > @@ -661,22 +660,24 @@ static int acpi_coresight_parse_graph(struct device *dev, > struct acpi_device *adev, > struct coresight_platform_data *pdata) > { > + int ret = 0; > int i, nlinks; > const union acpi_object *graph; > struct coresight_connection conn, zero_conn = {}; > struct coresight_connection *new_conn; > + struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL }; > > - graph = acpi_get_coresight_graph(adev); > + graph = acpi_get_coresight_graph(adev, &buf); > /* > * There are no graph connections, which is fine for some components. > * e.g., ETE > */ > if (!graph) > - return 0; > + goto free; > > nlinks = graph->package.elements[2].integer.value; > if (!nlinks) > - return 0; > + goto free; > > for (i = 0; i < nlinks; i++) { > const union acpi_object *link = &graph->package.elements[3 + i]; > @@ -684,17 +685,28 @@ static int acpi_coresight_parse_graph(struct device *dev, > > conn = zero_conn; > dir = acpi_coresight_parse_link(adev, link, &conn); > - if (dir < 0) > - return dir; > + if (dir < 0) { > + ret = dir; > + goto free; > + } > > if (dir == ACPI_CORESIGHT_LINK_MASTER) { > new_conn = coresight_add_out_conn(dev, pdata, &conn); > - if (IS_ERR(new_conn)) > - return PTR_ERR(new_conn); > + if (IS_ERR(new_conn)) { > + ret = PTR_ERR(new_conn); > + goto free; > + } > } > } > > - return 0; > +free: > + /* > + * When ACPI fails to alloc a buffer, it will free the buffer > + * created via ACPI_ALLOCATE_BUFFER and set to NULL. > + * ACPI_FREE can handle NULL pointers, so free it directly. > + */ > + ACPI_FREE(buf.pointer); > + return ret; > } > > /*
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