ASoC: max9759: fix underflow in speaker_gain_control_put()
commit
4c907bcd9dcd233da6707059d777ab389dcbd964 upstream.
Check for negative values of "priv->gain" to prevent an out of bounds
access. The concern is that these might come from the user via:
-> snd_ctl_elem_write_user()
-> snd_ctl_elem_write()
-> kctl->put()
Fixes:
fa8d915172b8 ("ASoC: max9759: Add Amplifier Driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220119123101.GA9509@kili
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>