ALSA: hwdep: fix a left shifting 1 by 31 UB bug

BugLink: https://bugs.launchpad.net/bugs/1883917

[ Upstream commit fb8cd648 ]

The "info.index" variable can be 31 in "1 << info.index".
This might trigger an undefined behavior since 1 is signed.

Fix this by casting 1 to 1u just to be sure "1u << 31" is defined.
Signed-off-by: Changming Liu <liu.changm@northeastern.edu>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/BL0PR06MB4548170B842CB055C9AF695DE5B00@BL0PR06MB4548.namprd06.prod.outlook.comSigned-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

sound/core/hwdep.c

@@ -228,14 +228,14 @@ static int snd_hwdep_dsp_load(struct snd_hwdep *hw,
 	if (copy_from_user(&info, _info, sizeof(info)))
 		return -EFAULT;
 	/* check whether the dsp was already loaded */
-	if (hw->dsp_loaded & (1 << info.index))
+	if (hw->dsp_loaded & (1u << info.index))
 		return -EBUSY;
 	if (!access_ok(VERIFY_READ, info.image, info.length))
 		return -EFAULT;
 	err = hw->ops.dsp_load(hw, &info);
 	if (err < 0)
 		return err;
-	hw->dsp_loaded |= (1 << info.index);
+	hw->dsp_loaded |= (1u << info.index);
 	return 0;
 }