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| author | Junrui Luo <moonafterrain@outlook.com> | 2025-12-03 07:27:03 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-01-11 17:21:38 +0300 |
| commit | ddd32ec66bc4eb6969fe835e4cc1c0706c6348fe (patch) | |
| tree | c6b0c6ba19e5fcc9bb15a836b85032ee679ad157 | |
| parent | 1e59c7587bb08f003159cd3612596536744c3db3 (diff) | |
| download | linux-ddd32ec66bc4eb6969fe835e4cc1c0706c6348fe.tar.xz | |
ALSA: firewire-motu: fix buffer overflow in hwdep read for DSP events
[ Upstream commit 210d77cca3d0494ed30a5c628b20c1d95fa04fb1 ]
The DSP event handling code in hwdep_read() could write more bytes to
the user buffer than requested, when a user provides a buffer smaller
than the event header size (8 bytes).
Fix by using min_t() to clamp the copy size, This ensures we never copy
more than the user requested.
Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Reported-by: Junrui Luo <moonafterrain@outlook.com>
Fixes: 634ec0b2906e ("ALSA: firewire-motu: notify event for parameter change in register DSP model")
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Link: https://patch.msgid.link/SYBPR01MB78810656377E79E58350D951AFD9A@SYBPR01MB7881.ausprd01.prod.outlook.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | sound/firewire/motu/motu-hwdep.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/sound/firewire/motu/motu-hwdep.c b/sound/firewire/motu/motu-hwdep.c index a220ac0c8eb8..28885c8004ae 100644 --- a/sound/firewire/motu/motu-hwdep.c +++ b/sound/firewire/motu/motu-hwdep.c @@ -83,10 +83,11 @@ static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count, event.motu_register_dsp_change.type = SNDRV_FIREWIRE_EVENT_MOTU_REGISTER_DSP_CHANGE; event.motu_register_dsp_change.count = (consumed - sizeof(event.motu_register_dsp_change)) / 4; - if (copy_to_user(buf, &event, sizeof(event.motu_register_dsp_change))) + if (copy_to_user(buf, &event, + min_t(long, count, sizeof(event.motu_register_dsp_change)))) return -EFAULT; - count = consumed; + count = min_t(long, count, consumed); } else { spin_unlock_irq(&motu->lock); |