slimbus: messaging: Free transaction ID in delayed interrupt scenario

In case of interrupt delay for any reason, slim_do_transfer()
returns timeout error but the transaction ID (TID) is not freed.
This results into invalid memory access inside
qcom_slim_ngd_rx_msgq_cb() due to invalid TID.

Fix the issue by freeing the TID in slim_do_transfer() before
returning timeout error to avoid invalid memory access.

Call trace:
__memcpy_fromio+0x20/0x190
qcom_slim_ngd_rx_msgq_cb+0x130/0x290 [slim_qcom_ngd_ctrl]
vchan_complete+0x2a0/0x4a0
tasklet_action_common+0x274/0x700
tasklet_action+0x28/0x3c
_stext+0x188/0x620
run_ksoftirqd+0x34/0x74
smpboot_thread_fn+0x1d8/0x464
kthread+0x178/0x238
ret_from_fork+0x10/0x20
Code: aa0003e8 91000429 f100044a 3940002b (3800150b)
---[ end trace 0fe00bec2b975c99 ]---
Kernel panic - not syncing: Oops: Fatal exception in interrupt.

Fixes: afbdcc7c384b ("slimbus: Add messaging APIs to slimbus framework")
Cc: stable <stable@kernel.org>
Signed-off-by: Visweswara Tanuku <quic_vtanuku@quicinc.com>
Link: https://lore.kernel.org/r/20250124125740.16897-1-quic_vtanuku@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/slimbus/messaging.c b/drivers/slimbus/messaging.c
index e7aa9bd4b44b8627c2ffc6135e683a7fdf150df8..6f01d944f9c65ad9b0807c89291b8f34c3ac661c 100644 (file)
--- a/drivers/slimbus/messaging.c
+++ b/drivers/slimbus/messaging.c
@@ -148,8 +148,9 @@ int slim_do_transfer(struct slim_controller *ctrl, struct slim_msg_txn *txn)
        }
 
        ret = ctrl->xfer_msg(ctrl, txn);
-
-       if (!ret && need_tid && !txn->msg->comp) {
+       if (ret == -ETIMEDOUT) {
+               slim_free_txn_tid(ctrl, txn);
+       } else if (!ret && need_tid && !txn->msg->comp) {
                unsigned long ms = txn->rl + HZ;
 
                time_left = wait_for_completion_timeout(txn->comp,