| Message ID | 1531234709-6783-2-git-send-email-paolo.pisati@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | ALSA: usb-audio: Kill stray URB at exiting | expand |
On 10.07.2018 16:58, Paolo Pisati wrote: > From: Takashi Iwai <tiwai@suse.de> > > USB-audio driver may leave a stray URB for the mixer interrupt when it > exits by some error during probe. This leads to a use-after-free > error as spotted by syzkaller like: > ================================================================== > BUG: KASAN: use-after-free in snd_usb_mixer_interrupt+0x604/0x6f0 > Call Trace: > <IRQ> > __dump_stack lib/dump_stack.c:16 > dump_stack+0x292/0x395 lib/dump_stack.c:52 > print_address_description+0x78/0x280 mm/kasan/report.c:252 > kasan_report_error mm/kasan/report.c:351 > kasan_report+0x23d/0x350 mm/kasan/report.c:409 > __asan_report_load8_noabort+0x19/0x20 mm/kasan/report.c:430 > snd_usb_mixer_interrupt+0x604/0x6f0 sound/usb/mixer.c:2490 > __usb_hcd_giveback_urb+0x2e0/0x650 drivers/usb/core/hcd.c:1779 > .... > > Allocated by task 1484: > save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59 > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 > kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 > kmem_cache_alloc_trace+0x11e/0x2d0 mm/slub.c:2772 > kmalloc ./include/linux/slab.h:493 > kzalloc ./include/linux/slab.h:666 > snd_usb_create_mixer+0x145/0x1010 sound/usb/mixer.c:2540 > create_standard_mixer_quirk+0x58/0x80 sound/usb/quirks.c:516 > snd_usb_create_quirk+0x92/0x100 sound/usb/quirks.c:560 > create_composite_quirk+0x1c4/0x3e0 sound/usb/quirks.c:59 > snd_usb_create_quirk+0x92/0x100 sound/usb/quirks.c:560 > usb_audio_probe+0x1040/0x2c10 sound/usb/card.c:618 > .... > > Freed by task 1484: > save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59 > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 > kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:524 > slab_free_hook mm/slub.c:1390 > slab_free_freelist_hook mm/slub.c:1412 > slab_free mm/slub.c:2988 > kfree+0xf6/0x2f0 mm/slub.c:3919 > snd_usb_mixer_free+0x11a/0x160 sound/usb/mixer.c:2244 > snd_usb_mixer_dev_free+0x36/0x50 sound/usb/mixer.c:2250 > __snd_device_free+0x1ff/0x380 sound/core/device.c:91 > snd_device_free_all+0x8f/0xe0 sound/core/device.c:244 > snd_card_do_free sound/core/init.c:461 > release_card_device+0x47/0x170 sound/core/init.c:181 > device_release+0x13f/0x210 drivers/base/core.c:814 > .... > > Actually such a URB is killed properly at disconnection when the > device gets probed successfully, and what we need is to apply it for > the error-path, too. > > In this patch, we apply snd_usb_mixer_disconnect() at releasing. > Also introduce a new flag, disconnected, to struct usb_mixer_interface > for not performing the disconnection procedure twice. > > Reported-by: Andrey Konovalov <andreyknvl@google.com> > Tested-by: Andrey Konovalov <andreyknvl@google.com> > Cc: <stable@vger.kernel.org> > Signed-off-by: Takashi Iwai <tiwai@suse.de> > (cherry picked from commit 124751d5e63c823092060074bd0abaae61aaa9c4) > Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com> Acked-by: Stefan Bader <stefan.bader@canonical.com> > --- > sound/usb/card.c | 5 ++++- > sound/usb/mixer.c | 17 +++++++++++------ > sound/usb/mixer.h | 4 +++- > 3 files changed, 18 insertions(+), 8 deletions(-) > > diff --git a/sound/usb/card.c b/sound/usb/card.c > index ab433a0..abd816d 100644 > --- a/sound/usb/card.c > +++ b/sound/usb/card.c > @@ -616,7 +616,10 @@ static void snd_usb_audio_disconnect(struct usb_device *dev, > } > /* release mixer resources */ > list_for_each(p, &chip->mixer_list) { > - snd_usb_mixer_disconnect(p); > + struct usb_mixer_interface *mixer; > + > + mixer = list_entry(p, struct usb_mixer_interface, list); > + snd_usb_mixer_disconnect(mixer); > } > } > > diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c > index 43492a6..b369c46 100644 > --- a/sound/usb/mixer.c > +++ b/sound/usb/mixer.c > @@ -2071,6 +2071,9 @@ static int parse_audio_unit(struct mixer_build *state, int unitid) > > static void snd_usb_mixer_free(struct usb_mixer_interface *mixer) > { > + /* kill pending URBs */ > + snd_usb_mixer_disconnect(mixer); > + > kfree(mixer->id_elems); > if (mixer->urb) { > kfree(mixer->urb->transfer_buffer); > @@ -2412,11 +2415,13 @@ _error: > return err; > } > > -void snd_usb_mixer_disconnect(struct list_head *p) > +void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer) > { > - struct usb_mixer_interface *mixer; > - > - mixer = list_entry(p, struct usb_mixer_interface, list); > - usb_kill_urb(mixer->urb); > - usb_kill_urb(mixer->rc_urb); > + if (mixer->disconnected) > + return; > + if (mixer->urb) > + usb_kill_urb(mixer->urb); > + if (mixer->rc_urb) > + usb_kill_urb(mixer->rc_urb); > + mixer->disconnected = true; > } > diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h > index aab80df..f74a4d6 100644 > --- a/sound/usb/mixer.h > +++ b/sound/usb/mixer.h > @@ -23,6 +23,8 @@ struct usb_mixer_interface { > > u8 audigy2nx_leds[3]; > u8 xonar_u1_status; > + > + bool disconnected; > }; > > #define MAX_CHANNELS 16 /* max logical channels */ > @@ -57,7 +59,7 @@ struct usb_mixer_elem_info { > > int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif, > int ignore_error); > -void snd_usb_mixer_disconnect(struct list_head *p); > +void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer); > > void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid); > >
On 07/10/2018 04:58 PM, Paolo Pisati wrote: > From: Takashi Iwai <tiwai@suse.de> Added missing CVE line. > USB-audio driver may leave a stray URB for the mixer interrupt when it > exits by some error during probe. This leads to a use-after-free > error as spotted by syzkaller like: > ================================================================== > BUG: KASAN: use-after-free in snd_usb_mixer_interrupt+0x604/0x6f0 > Call Trace: > <IRQ> > __dump_stack lib/dump_stack.c:16 > dump_stack+0x292/0x395 lib/dump_stack.c:52 > print_address_description+0x78/0x280 mm/kasan/report.c:252 > kasan_report_error mm/kasan/report.c:351 > kasan_report+0x23d/0x350 mm/kasan/report.c:409 > __asan_report_load8_noabort+0x19/0x20 mm/kasan/report.c:430 > snd_usb_mixer_interrupt+0x604/0x6f0 sound/usb/mixer.c:2490 > __usb_hcd_giveback_urb+0x2e0/0x650 drivers/usb/core/hcd.c:1779 > .... > > Allocated by task 1484: > save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59 > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 > kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 > kmem_cache_alloc_trace+0x11e/0x2d0 mm/slub.c:2772 > kmalloc ./include/linux/slab.h:493 > kzalloc ./include/linux/slab.h:666 > snd_usb_create_mixer+0x145/0x1010 sound/usb/mixer.c:2540 > create_standard_mixer_quirk+0x58/0x80 sound/usb/quirks.c:516 > snd_usb_create_quirk+0x92/0x100 sound/usb/quirks.c:560 > create_composite_quirk+0x1c4/0x3e0 sound/usb/quirks.c:59 > snd_usb_create_quirk+0x92/0x100 sound/usb/quirks.c:560 > usb_audio_probe+0x1040/0x2c10 sound/usb/card.c:618 > .... > > Freed by task 1484: > save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59 > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 > kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:524 > slab_free_hook mm/slub.c:1390 > slab_free_freelist_hook mm/slub.c:1412 > slab_free mm/slub.c:2988 > kfree+0xf6/0x2f0 mm/slub.c:3919 > snd_usb_mixer_free+0x11a/0x160 sound/usb/mixer.c:2244 > snd_usb_mixer_dev_free+0x36/0x50 sound/usb/mixer.c:2250 > __snd_device_free+0x1ff/0x380 sound/core/device.c:91 > snd_device_free_all+0x8f/0xe0 sound/core/device.c:244 > snd_card_do_free sound/core/init.c:461 > release_card_device+0x47/0x170 sound/core/init.c:181 > device_release+0x13f/0x210 drivers/base/core.c:814 > .... > > Actually such a URB is killed properly at disconnection when the > device gets probed successfully, and what we need is to apply it for > the error-path, too. > > In this patch, we apply snd_usb_mixer_disconnect() at releasing. > Also introduce a new flag, disconnected, to struct usb_mixer_interface > for not performing the disconnection procedure twice. > > Reported-by: Andrey Konovalov <andreyknvl@google.com> > Tested-by: Andrey Konovalov <andreyknvl@google.com> > Cc: <stable@vger.kernel.org> > Signed-off-by: Takashi Iwai <tiwai@suse.de> > (cherry picked from commit 124751d5e63c823092060074bd0abaae61aaa9c4) > Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com> Signed-off-by: Juerg Haefliger <juergh@canonical.com> Applied to trusty master-next. ...Juerg > --- > sound/usb/card.c | 5 ++++- > sound/usb/mixer.c | 17 +++++++++++------ > sound/usb/mixer.h | 4 +++- > 3 files changed, 18 insertions(+), 8 deletions(-) > > diff --git a/sound/usb/card.c b/sound/usb/card.c > index ab433a0..abd816d 100644 > --- a/sound/usb/card.c > +++ b/sound/usb/card.c > @@ -616,7 +616,10 @@ static void snd_usb_audio_disconnect(struct usb_device *dev, > } > /* release mixer resources */ > list_for_each(p, &chip->mixer_list) { > - snd_usb_mixer_disconnect(p); > + struct usb_mixer_interface *mixer; > + > + mixer = list_entry(p, struct usb_mixer_interface, list); > + snd_usb_mixer_disconnect(mixer); > } > } > > diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c > index 43492a6..b369c46 100644 > --- a/sound/usb/mixer.c > +++ b/sound/usb/mixer.c > @@ -2071,6 +2071,9 @@ static int parse_audio_unit(struct mixer_build *state, int unitid) > > static void snd_usb_mixer_free(struct usb_mixer_interface *mixer) > { > + /* kill pending URBs */ > + snd_usb_mixer_disconnect(mixer); > + > kfree(mixer->id_elems); > if (mixer->urb) { > kfree(mixer->urb->transfer_buffer); > @@ -2412,11 +2415,13 @@ _error: > return err; > } > > -void snd_usb_mixer_disconnect(struct list_head *p) > +void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer) > { > - struct usb_mixer_interface *mixer; > - > - mixer = list_entry(p, struct usb_mixer_interface, list); > - usb_kill_urb(mixer->urb); > - usb_kill_urb(mixer->rc_urb); > + if (mixer->disconnected) > + return; > + if (mixer->urb) > + usb_kill_urb(mixer->urb); > + if (mixer->rc_urb) > + usb_kill_urb(mixer->rc_urb); > + mixer->disconnected = true; > } > diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h > index aab80df..f74a4d6 100644 > --- a/sound/usb/mixer.h > +++ b/sound/usb/mixer.h > @@ -23,6 +23,8 @@ struct usb_mixer_interface { > > u8 audigy2nx_leds[3]; > u8 xonar_u1_status; > + > + bool disconnected; > }; > > #define MAX_CHANNELS 16 /* max logical channels */ > @@ -57,7 +59,7 @@ struct usb_mixer_elem_info { > > int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif, > int ignore_error); > -void snd_usb_mixer_disconnect(struct list_head *p); > +void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer); > > void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid); > >
diff --git a/sound/usb/card.c b/sound/usb/card.c index ab433a0..abd816d 100644 --- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -616,7 +616,10 @@ static void snd_usb_audio_disconnect(struct usb_device *dev, } /* release mixer resources */ list_for_each(p, &chip->mixer_list) { - snd_usb_mixer_disconnect(p); + struct usb_mixer_interface *mixer; + + mixer = list_entry(p, struct usb_mixer_interface, list); + snd_usb_mixer_disconnect(mixer); } } diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 43492a6..b369c46 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -2071,6 +2071,9 @@ static int parse_audio_unit(struct mixer_build *state, int unitid) static void snd_usb_mixer_free(struct usb_mixer_interface *mixer) { + /* kill pending URBs */ + snd_usb_mixer_disconnect(mixer); + kfree(mixer->id_elems); if (mixer->urb) { kfree(mixer->urb->transfer_buffer); @@ -2412,11 +2415,13 @@ _error: return err; } -void snd_usb_mixer_disconnect(struct list_head *p) +void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer) { - struct usb_mixer_interface *mixer; - - mixer = list_entry(p, struct usb_mixer_interface, list); - usb_kill_urb(mixer->urb); - usb_kill_urb(mixer->rc_urb); + if (mixer->disconnected) + return; + if (mixer->urb) + usb_kill_urb(mixer->urb); + if (mixer->rc_urb) + usb_kill_urb(mixer->rc_urb); + mixer->disconnected = true; } diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h index aab80df..f74a4d6 100644 --- a/sound/usb/mixer.h +++ b/sound/usb/mixer.h @@ -23,6 +23,8 @@ struct usb_mixer_interface { u8 audigy2nx_leds[3]; u8 xonar_u1_status; + + bool disconnected; }; #define MAX_CHANNELS 16 /* max logical channels */ @@ -57,7 +59,7 @@ struct usb_mixer_elem_info { int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif, int ignore_error); -void snd_usb_mixer_disconnect(struct list_head *p); +void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer); void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid);