This is a note to let you know that I've just added the patch titled usb: gadget: u_audio: Clear uac pointer when freed. to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-gadget-u_audio-clear-uac-pointer-when-freed.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 059c4da064ad5a2cfe6a00779a97052d8cb37bd4 Author: Chris Wulff <Chris.Wulff@xxxxxxxxx> Date: Thu Apr 25 15:20:20 2024 +0000 usb: gadget: u_audio: Clear uac pointer when freed. [ Upstream commit a2cf936ebef291ef7395172b9e2f624779fb6dc0 ] This prevents use of a stale pointer if functions are called after g_cleanup that shouldn't be. This doesn't fix any races, but converts a possibly silent kernel memory corruption into an obvious NULL pointer dereference report. Fixes: eb9fecb9e69b ("usb: gadget: f_uac2: split out audio core") Signed-off-by: Chris Wulff <chris.wulff@xxxxxxxxx> Link: https://lore.kernel.org/stable/CO1PR17MB54194226DA08BFC9EBD8C163E1172%40CO1PR17MB5419.namprd17.prod.outlook.com Link: https://lore.kernel.org/r/CO1PR17MB54194226DA08BFC9EBD8C163E1172@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c index 53b30de16a896..994316d51a0e1 100644 --- a/drivers/usb/gadget/function/u_audio.c +++ b/drivers/usb/gadget/function/u_audio.c @@ -624,6 +624,8 @@ void g_audio_cleanup(struct g_audio *g_audio) return; uac = g_audio->uac; + g_audio->uac = NULL; + card = uac->card; if (card) snd_card_free_when_closed(card);