6.18-stable review patch. If anyone has any objections, please let me know.
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From: Shipei Qu qu@darknavy.com
[ Upstream commit 5526c1c6ba1d0913c7dfcbbd6fe1744ea7c55f1e ]
get_meter_levels_from_urb() parses the 64-byte meter packets sent by the device and fills the per-channel arrays meter_level[], comp_level[] and master_level[] in struct snd_us16x08_meter_store.
Currently the function derives the channel index directly from the meter packet (MUB2(meter_urb, s) - 1) and uses it to index those arrays without validating the range. If the packet contains a negative or out-of-range channel number, the driver may write past the end of these arrays.
Introduce a local channel variable and validate it before updating the arrays. We reject negative indices, limit meter_level[] and comp_level[] to SND_US16X08_MAX_CHANNELS, and guard master_level[] updates with ARRAY_SIZE(master_level).
Fixes: d2bb390a2081 ("ALSA: usb-audio: Tascam US-16x08 DSP mixer quirk") Reported-by: DARKNAVY (@DarkNavyOrg) vr@darknavy.com Closes: https://lore.kernel.org/tencent_21C112743C44C1A2517FF219@qq.com Signed-off-by: Shipei Qu qu@darknavy.com Link: https://patch.msgid.link/20251217024630.59576-1-qu@darknavy.com Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- sound/usb/mixer_us16x08.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/sound/usb/mixer_us16x08.c b/sound/usb/mixer_us16x08.c index 1c5712c31f5e..f9df40730eff 100644 --- a/sound/usb/mixer_us16x08.c +++ b/sound/usb/mixer_us16x08.c @@ -655,17 +655,25 @@ static void get_meter_levels_from_urb(int s, u8 *meter_urb) { int val = MUC2(meter_urb, s) + (MUC3(meter_urb, s) << 8); + int ch = MUB2(meter_urb, s) - 1; + + if (ch < 0) + return;
if (MUA0(meter_urb, s) == 0x61 && MUA1(meter_urb, s) == 0x02 && MUA2(meter_urb, s) == 0x04 && MUB0(meter_urb, s) == 0x62) { - if (MUC0(meter_urb, s) == 0x72) - store->meter_level[MUB2(meter_urb, s) - 1] = val; - if (MUC0(meter_urb, s) == 0xb2) - store->comp_level[MUB2(meter_urb, s) - 1] = val; + if (ch < SND_US16X08_MAX_CHANNELS) { + if (MUC0(meter_urb, s) == 0x72) + store->meter_level[ch] = val; + if (MUC0(meter_urb, s) == 0xb2) + store->comp_level[ch] = val; + } } if (MUA0(meter_urb, s) == 0x61 && MUA1(meter_urb, s) == 0x02 && - MUA2(meter_urb, s) == 0x02 && MUB0(meter_urb, s) == 0x62) - store->master_level[MUB2(meter_urb, s) - 1] = val; + MUA2(meter_urb, s) == 0x02 && MUB0(meter_urb, s) == 0x62) { + if (ch < ARRAY_SIZE(store->master_level)) + store->master_level[ch] = val; + } }
/* Function to retrieve current meter values from the device.