| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 43/77] ALSA: hwdep: fix a left shifting 1 by 31 UB bug | Date | Mon, 1 Jun 2020 19:53:48 +0200 |
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From: Changming Liu <liu.changm@northeastern.edu>
[ Upstream commit fb8cd6481ffd126f35e9e146a0dcf0c4e8899f2e ]
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.com Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org> --- sound/core/hwdep.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sound/core/hwdep.c b/sound/core/hwdep.c index a73baa1242be..727219f40201 100644 --- a/sound/core/hwdep.c +++ b/sound/core/hwdep.c @@ -229,14 +229,14 @@ 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; } -- 2.25.1
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