linux/sound/usb/helper.h
Takashi Iwai 57f8770620 ALSA: usb-audio: More validations of descriptor units
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>
2019-08-22 10:35:59 +02:00

39 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __USBAUDIO_HELPER_H
#define __USBAUDIO_HELPER_H
unsigned int snd_usb_combine_bytes(unsigned char *bytes, int size);
void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype);
void *snd_usb_find_csint_desc(void *descstart, int desclen, void *after, u8 dsubtype);
int snd_usb_pipe_sanity_check(struct usb_device *dev, unsigned int pipe);
int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe,
__u8 request, __u8 requesttype, __u16 value, __u16 index,
void *data, __u16 size);
unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip,
struct usb_host_interface *alts);
/*
* retrieve usb_interface descriptor from the host interface
* (conditional for compatibility with the older API)
*/
#define get_iface_desc(iface) (&(iface)->desc)
#define get_endpoint(alt,ep) (&(alt)->endpoint[ep].desc)
#define get_ep_desc(ep) (&(ep)->desc)
#define get_cfg_desc(cfg) (&(cfg)->desc)
#define snd_usb_get_speed(dev) ((dev)->speed)
static inline int snd_usb_ctrl_intf(struct snd_usb_audio *chip)
{
return get_iface_desc(chip->ctrl_intf)->bInterfaceNumber;
}
/* in validate.c */
bool snd_usb_validate_audio_desc(void *p, int protocol);
bool snd_usb_validate_midi_desc(void *p);
#endif /* __USBAUDIO_HELPER_H */