4 Commits

Author SHA1 Message Date
Takashi Iwai
a46ebc21da ALSA: usb-audio: Fix endianess in descriptor validation
commit f8e5f90b3a53bb75f05124ed19156388379a337d upstream.

I overlooked that some fields are words and need the converts from
LE in the recently added USB descriptor validation code.
This patch fixes those with the proper macro usages.

Fixes: 57f8770620e9 ("ALSA: usb-audio: More validations of descriptor units")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200201080530.22390-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:33:56 -08:00
Takashi Iwai
f246552686 ALSA: usb-audio: Fix incorrect size check for processing/extension units
commit 976a68f06b2ea49e2ab67a5f84919a8b105db8be upstream.

The recently introduced unit descriptor validation had some bug for
processing and extension units, it counts a bControlSize byte twice so
it expected a bigger size than it should have been.  This seems
resulting in a probe error on a few devices.

Fix the calculation for proper checks of PU and EU.

Fixes: 57f8770620e9 ("ALSA: usb-audio: More validations of descriptor units")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191114165613.7422-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-20 18:45:13 +01:00
Takashi Iwai
4ebee4875e ALSA: usb-audio: Fix copy&paste error in the validator
commit ba8bf0967a154796be15c4983603aad0b05c3138 upstream.

The recently introduced USB-audio descriptor validator had a stupid
copy&paste error that may lead to an unexpected overlook of too short
descriptors for processing and extension units.  It's likely the cause
of the report triggered by syzkaller fuzzer.  Let's fix it.

Fixes: 57f8770620e9 ("ALSA: usb-audio: More validations of descriptor units")
Reported-by: syzbot+0620f79a1978b1133fd7@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/s5hsgnkdbsl.wl-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12 19:20:50 +01:00
Takashi Iwai
17821e2fb1 ALSA: usb-audio: More validations of descriptor units
commit 57f8770620e9b51c61089751f0b5ad3dbe376ff2 upstream.

Introduce a new helper to validate each audio descriptor unit before
and check the unit before actually accessing it.  This should harden
against the OOB access cases with malformed descriptors that have been
recently frequently reported by fuzzers.

The existing descriptor checks are still kept although they become
superfluous after this patch.  They'll be cleaned up eventually
later.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12 19:20:48 +01:00