ASoC: SOF: ipc3-control: Fix TOCTOU in bytes_put and bytes_get

In sof_ipc3_bytes_put(), the size used for the memcpy is derived from
the old data->size already in the buffer, not the incoming new data's
size field. If the new data has a different size, the copy length is
wrong: it may truncate valid data or copy stale bytes.

Similarly, sof_ipc3_bytes_get() checks data->size against max_size
without accounting for the sizeof(struct sof_ipc_ctrl_data) offset
of the flex array within the allocation.

Fix bytes_put to validate and use the incoming data's sof_abi_hdr.size
from ucontrol before copying. Fix bytes_get to subtract sizeof(*cdata)
from the bounds check to match the actual available space.

Fixes: 544ac8858f24 ("ASoC: SOF: Add bytes_get/put control IPC ops for IPC3")
Cc: stable@vger.kernel.org
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://patch.msgid.link/20260609083458.31193-6-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/sof/ipc3-control.c b/sound/soc/sof/ipc3-control.c
index 4b907d8cf58ad5ac5ff226be7af2d16284d2d079..1f5538bbc50f054ef8e0c2a53b59d30ab69580b6 100644 (file)
--- a/sound/soc/sof/ipc3-control.c
+++ b/sound/soc/sof/ipc3-control.c
@@ -315,10 +315,13 @@ static int sof_ipc3_bytes_get(struct snd_sof_control *scontrol,
        }
 
        /* be->max has been verified to be >= sizeof(struct sof_abi_hdr) */
-       if (data->size > scontrol->max_size - sizeof(*data)) {
+       if (data->size > scontrol->max_size - sizeof(*cdata) -
+                                   sizeof(*data)) {
                dev_err_ratelimited(scomp->dev,
                                    "%u bytes of control data is invalid, max is %zu\n",
-                                   data->size, scontrol->max_size - sizeof(*data));
+                                   data->size,
+                                   scontrol->max_size - sizeof(*cdata) -
+                                   sizeof(*data));
                return -EINVAL;
        }
 
@@ -336,6 +339,8 @@ static int sof_ipc3_bytes_put(struct snd_sof_control *scontrol,
        struct sof_ipc_ctrl_data *cdata = scontrol->ipc_control_data;
        struct snd_soc_component *scomp = scontrol->scomp;
        struct sof_abi_hdr *data = cdata->data;
+       const struct sof_abi_hdr *new_hdr =
+               (const struct sof_abi_hdr *)ucontrol->value.bytes.data;
        size_t size;
 
        if (scontrol->max_size > sizeof(ucontrol->value.bytes.data)) {
@@ -344,14 +349,18 @@ static int sof_ipc3_bytes_put(struct snd_sof_control *scontrol,
                return -EINVAL;
        }
 
-       /* scontrol->max_size has been verified to be >= sizeof(struct sof_abi_hdr) */
-       if (data->size > scontrol->max_size - sizeof(*data)) {
-               dev_err_ratelimited(scomp->dev, "data size too big %u bytes max is %zu\n",
-                                   data->size, scontrol->max_size - sizeof(*data));
+       /* Validate the new data's size, not the old one */
+       if (new_hdr->size > scontrol->max_size - sizeof(*cdata) -
+                                   sizeof(*new_hdr)) {
+               dev_err_ratelimited(scomp->dev,
+                                   "data size too big %u bytes max is %zu\n",
+                                   new_hdr->size,
+                                   scontrol->max_size - sizeof(*cdata) -
+                                   sizeof(*new_hdr));
                return -EINVAL;
        }
 
-       size = data->size + sizeof(*data);
+       size = new_hdr->size + sizeof(*new_hdr);
 
        /* copy from kcontrol */
        memcpy(data, ucontrol->value.bytes.data, size);