media: iris: Fix use-after-free in iris_release_internal_buffers()

The recent change in commit 1dabf00ee206 ("media: iris: gen1: Destroy
internal buffers after FW releases") introduced a regression where
session_release_buf() may free the buffer. The caller,
iris_release_internal_buffers(), continued to access `buffer` after the
call, leading to a potential use-after-free.

Fix this by setting BUF_ATTR_PENDING_RELEASE before calling
session_release_buf(), and reverting the flag if the call fails. This
ensures no dereference occurs after potential freeing.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Closes: https://lore.kernel.org/lkml/aYXvKAX3Pg3sL37P@stanley.mountain/#r
Signed-off-by: Dikshita Agarwal <dikshita.agarwal@oss.qualcomm.com>
Reviewed-by: Vikash Garodia <vikash.garodia@oss.qualcomm.com>
Fixes: 1dabf00ee206 ("media: iris: gen1: Destroy internal buffers after FW releases")
Cc: stable@vger.kernel.org
Signed-off-by: Bryan O'Donoghue <bod@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

diff --git a/drivers/media/platform/qcom/iris/iris_buffer.c b/drivers/media/platform/qcom/iris/iris_buffer.c
index 9151f43bc6b9c2c34c803de4231d1e6de0bec6c4..1d53c7414b754b79d67ea2d422ebc80cf635720b 100644 (file)
--- a/drivers/media/platform/qcom/iris/iris_buffer.c
+++ b/drivers/media/platform/qcom/iris/iris_buffer.c
@@ -582,10 +582,12 @@ static int iris_release_internal_buffers(struct iris_inst *inst,
                        continue;
                if (!(buffer->attr & BUF_ATTR_QUEUED))
                        continue;
+               buffer->attr |= BUF_ATTR_PENDING_RELEASE;
                ret = hfi_ops->session_release_buf(inst, buffer);
-               if (ret)
+               if (ret) {
+                       buffer->attr &= ~BUF_ATTR_PENDING_RELEASE;
                        return ret;
-               buffer->attr |= BUF_ATTR_PENDING_RELEASE;
+               }
        }
 
        return 0;