[PATCH] media: venus: fix use after free in vdec_close

From: Dikshita Agarwal
Date: Fri Apr 05 2024 - 11:52:45 EST


There appears to be a possible use after free with vdec_close().
The firmware will add buffer release work to the work queue through
HFI callbacks as a normal part of decoding. Randomly closing the
decoder device from userspace during normal decoding can incur
a read after free for inst.

Fix it by cancelling the delayed work in vdec_close.

Signed-off-by: Dikshita Agarwal <quic_dikshita@xxxxxxxxxxx>
---
drivers/media/platform/qcom/venus/vdec.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/media/platform/qcom/venus/vdec.c b/drivers/media/platform/qcom/venus/vdec.c
index 29130a9..8dda46a 100644
--- a/drivers/media/platform/qcom/venus/vdec.c
+++ b/drivers/media/platform/qcom/venus/vdec.c
@@ -1747,6 +1747,7 @@ static int vdec_close(struct file *file)

vdec_pm_get(inst);

+ cancel_delayed_work_sync(&inst->delayed_process_work);
v4l2_m2m_ctx_release(inst->m2m_ctx);
v4l2_m2m_release(inst->m2m_dev);
vdec_ctrl_deinit(inst);
--
2.7.4