kernel/linux.git/drivers/usb/gadget/function/u_audio.c, branch v5.10.264

usb: gadget: u_audio: Clear uac pointer when freed.

2024-06-16T11:32:20+00:00

[ 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 Link: https://lore.kernel.org/stable/CO1PR17MB54194226DA08BFC9EBD8C163E1172%40CO1PR17MB5419.namprd17.prod.outlook.com Link: https://lore.kernel.org/r/CO1PR17MB54194226DA08BFC9EBD8C163E1172@CO1PR17MB5419.namprd17.prod.outlook.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

usb: gadget: u_audio: don't let userspace block driver unbind

2023-04-05T09:23:40+00:00

commit 6c67ed9ad9b83e453e808f9b31a931a20a25629b upstream. In the unbind callback for f_uac1 and f_uac2, a call to snd_card_free() via g_audio_cleanup() will disconnect the card and then wait for all resources to be released, which happens when the refcount falls to zero. Since userspace can keep the refcount incremented by not closing the relevant file descriptor, the call to unbind may block indefinitely. This can cause a deadlock during reboot, as evidenced by the following blocked task observed on my machine: task:reboot state:D stack:0 pid:2827 ppid:569 flags:0x0000000c Call trace: __switch_to+0xc8/0x140 __schedule+0x2f0/0x7c0 schedule+0x60/0xd0 schedule_timeout+0x180/0x1d4 wait_for_completion+0x78/0x180 snd_card_free+0x90/0xa0 g_audio_cleanup+0x2c/0x64 afunc_unbind+0x28/0x60 ... kernel_restart+0x4c/0xac __do_sys_reboot+0xcc/0x1ec __arm64_sys_reboot+0x28/0x30 invoke_syscall+0x4c/0x110 ... The issue can also be observed by opening the card with arecord and then stopping the process through the shell before unbinding: # arecord -D hw:UAC2Gadget -f S32_LE -c 2 -r 48000 /dev/null Recording WAVE '/dev/null' : Signed 32 bit Little Endian, Rate 48000 Hz, Stereo ^Z[1]+ Stopped arecord -D hw:UAC2Gadget -f S32_LE -c 2 -r 48000 /dev/null # echo gadget.0 > /sys/bus/gadget/drivers/configfs-gadget/unbind (observe that the unbind command never finishes) Fix the problem by using snd_card_free_when_closed() instead, which will still disconnect the card as desired, but defer the task of freeing the resources to the core once userspace closes its file descriptor. Fixes: 132fcb460839 ("usb: gadget: Add Audio Class 2.0 Driver") Cc: stable@vger.kernel.org Signed-off-by: Alvin Šipraga Reviewed-by: Ruslan Bilovol Reviewed-by: John Keeping Link: https://lore.kernel.org/r/20230302163648.3349669-1-alvin@pqrs.dk Signed-off-by: Greg Kroah-Hartman

usb: gadget: u_audio: fix race condition on endpoint stop

2021-09-03T08:09:26+00:00

[ Upstream commit 068fdad20454f815e61e6f6eb9f051a8b3120e88 ] If the endpoint completion callback is call right after the ep_enabled flag is cleared and before usb_ep_dequeue() is call, we could do a double free on the request and the associated buffer. Fix this by clearing ep_enabled after all the endpoint requests have been dequeued. Fixes: 7de8681be2cd ("usb: gadget: u_audio: Free requests only after callback") Cc: stable Reported-by: Thinh Nguyen Signed-off-by: Jerome Brunet Link: https://lore.kernel.org/r/20210827092927.366482-1-jbrunet@baylibre.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

usb: gadget: u_audio: Free requests only after callback

2021-03-04T10:37:24+00:00

[ Upstream commit 7de8681be2cde9f6953d3be1fa6ce05f9fe6e637 ] As per the kernel doc for usb_ep_dequeue(), it states that "this routine is asynchronous, that is, it may return before the completion routine runs". And indeed since v5.0 the dwc3 gadget driver updated its behavior to place dequeued requests on to a cancelled list to be given back later after the endpoint is stopped. The free_ep() was incorrectly assuming that a request was ready to be freed after calling dequeue which results in a use-after-free in dwc3 when it traverses its cancelled list. Fix this by moving the usb_ep_free_request() call to the callback itself in case the ep is disabled. Fixes: eb9fecb9e69b0 ("usb: gadget: f_uac2: split out audio core") Reported-and-tested-by: Ferry Toth Reviewed-and-tested-by: Peter Chen Acked-by: Felipe Balbi Signed-off-by: Jack Pham Signed-off-by: Jerome Brunet Link: https://lore.kernel.org/r/20210118084642.322510-2-jbrunet@baylibre.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

usb: gadget: u_audio: Fix high-speed max packet size

2020-02-11T06:45:45+00:00

Prior to commit eb9fecb9e69b ("usb: gadget: f_uac2: split out audio core") the maximum packet size was calculated only from the high-speed descriptor but now we use the largest of the full-speed and high-speed descriptors. This is correct, but the full-speed value is likely to be higher than that for high-speed and this leads to submitting requests for OUT transfers (received by the gadget) which are larger than the endpoint's maximum packet size. These are rightly rejected by the gadget core. config_ep_by_speed() already sets up the correct maximum packet size for the enumerated speed in the usb_ep structure, so we can simply use this instead of the overall value that has been used to allocate buffers for requests. Note that the minimum period for ALSA is still set from the largest value, and this is unavoidable because it's possible to open the audio device before the gadget has been enumerated. Tested-by: Pavel Hofman Signed-off-by: John Keeping Signed-off-by: Felipe Balbi

usb: gadget: f_uac2: fix packet size calculation

2020-01-15T09:39:23+00:00

The packet size for USB audio must always be a multiple of the frame size, otherwise we are transmitting a partial frame which omits some channels (and these end up at the wrong offset in the next packet). Furthermore, it breaks the residue handling such that we end up trying to send a packet exceeding the maximum packet size for the endpoint. Signed-off-by: John Keeping Signed-off-by: Felipe Balbi Signed-off-by: Greg Kroah-Hartman

usb: gadget: u_audio: Drop superfluous ioctl PCM ops

2019-12-17T15:24:12+00:00

PCM core deals the empty ioctl field now as default. Let's kill the redundant lines. Signed-off-by: Takashi Iwai Link: https://lore.kernel.org/r/20191210141822.18705-3-tiwai@suse.de Signed-off-by: Greg Kroah-Hartman

usb: gadget: u_audio: Use managed buffer allocation

2019-12-17T15:24:11+00:00

Clean up the driver with the new managed buffer allocation API. The hw_params and hw_free callbacks became superfluous and dropped. Signed-off-by: Takashi Iwai Link: https://lore.kernel.org/r/20191210141822.18705-2-tiwai@suse.de Signed-off-by: Greg Kroah-Hartman

usb: gadget: u_audio: Remove superfluous snd_dma_continuous_data()

2019-11-09T17:04:18+00:00

The recent change (commit 08422d2c559d: "ALSA: memalloc: Allow NULL device for SNDRV_DMA_TYPE_CONTINUOUS type") made the PCM preallocation helper accepting NULL as the device pointer for the default usage. Drop the snd_dma_continuous_data() usage that became superfluous from the callers. Acked-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20191108164214.611-1-tiwai@suse.de Signed-off-by: Takashi Iwai

usb: gadget: u_audio: Fixed variable declaration coding style issue

2019-06-18T08:58:28+00:00

Fixed a coding style issue, replacing unsigned with unsigned int. Reviewed-by: Eugeniu Rosca Signed-off-by: Jonas Stenvall Signed-off-by: Felipe Balbi