[PATCH] ALSA: usb-audio: qcom: Guard sideband endpoint removal

[PATCH] ALSA: usb-audio: qcom: Guard sideband endpoint removal

[Cássio Gabriel]

qmi_stop_session() conditionally looks up the cached data and sync
endpoints, but removes each endpoint unconditionally.

The data endpoint is always present for an active offload stream, while
the sync endpoint is optional. When no sync endpoint exists, ep still
refers to the data endpoint and the code attempts to remove that endpoint
a second time. The current sideband implementation rejects the duplicate
removal, but the teardown path should not pass an unrelated endpoint for
an absent sync endpoint.

Only look up and remove an endpoint when its cached pipe exists, check the
lookup result, and clear the cached pipe after handling it. This matches
the normal stream-disable path.

Fixes: 326bbc348298 ("ALSA: usb-audio: qcom: Introduce QC USB SND offloading support")
Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
---
base-commit: 950425465c4e97d699fedb738ea6ffd456a40514
---
 sound/usb/qcom/qc_audio_offload.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c
index b2b719238b0b..a3f90cc7c6ca 100644
--- a/sound/usb/qcom/qc_audio_offload.c
+++ b/sound/usb/qcom/qc_audio_offload.c
@@ -794,15 +794,23 @@ static void qmi_stop_session(void)
 				continue;
 			}
 			/* Release XHCI endpoints */
-			if (info->data_ep_pipe)
+			if (info->data_ep_pipe) {
 				ep = usb_pipe_endpoint(uadev[pcm_card_num].udev,
 						       info->data_ep_pipe);
-			xhci_sideband_remove_endpoint(uadev[pcm_card_num].sb, ep);
+				if (ep)
+					xhci_sideband_remove_endpoint(uadev[pcm_card_num].sb,
+								      ep);
+				info->data_ep_pipe = 0;
+			}
 
-			if (info->sync_ep_pipe)
+			if (info->sync_ep_pipe) {
 				ep = usb_pipe_endpoint(uadev[pcm_card_num].udev,
 						       info->sync_ep_pipe);
-			xhci_sideband_remove_endpoint(uadev[pcm_card_num].sb, ep);
+				if (ep)
+					xhci_sideband_remove_endpoint(uadev[pcm_card_num].sb,
+								      ep);
+				info->sync_ep_pipe = 0;
+			}
 
 			disable_audio_stream(subs);
 		}

Re: [PATCH] ALSA: usb-audio: qcom: Guard sideband endpoint removal

[Takashi Iwai]

On Thu, 11 Jun 2026 15:57:22 +0200,
Cássio Gabriel wrote:
> 
> qmi_stop_session() conditionally looks up the cached data and sync
> endpoints, but removes each endpoint unconditionally.
> 
> The data endpoint is always present for an active offload stream, while
> the sync endpoint is optional. When no sync endpoint exists, ep still
> refers to the data endpoint and the code attempts to remove that endpoint
> a second time. The current sideband implementation rejects the duplicate
> removal, but the teardown path should not pass an unrelated endpoint for
> an absent sync endpoint.
> 
> Only look up and remove an endpoint when its cached pipe exists, check the
> lookup result, and clear the cached pipe after handling it. This matches
> the normal stream-disable path.
> 
> Fixes: 326bbc348298 ("ALSA: usb-audio: qcom: Introduce QC USB SND offloading support")
> Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>

Applied to for-next branch now.  Thanks.


Takashi