KASAN: slab-out-of-bounds Read in build_audio_procunit

Status: fixed on 2019/11/06 12:39
Subsystems: usb sound
[Documentation on labels]
Reported-by: syzbot+0620f79a1978b1133fd7@syzkaller.appspotmail.com
Fix commit: ba8bf0967a15 ALSA: usb-audio: Fix copy&paste error in the validator
First crash: 2473d, last: 2462d
▶ ▼ Duplicate bugs (5)
Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
KASAN: use-after-free Read in parse_term_proc_unit usb sound 19 syz, C 5 2467d 2469d 0/29 closed as dup on 2019/10/24 13:49
KASAN: slab-out-of-bounds Read in parse_term_proc_unit usb sound 17 syz, C 3 2465d 2470d 0/29 closed as dup on 2019/10/23 05:07
KMSAN: uninit-value in build_audio_procunit sound usb 7 syz, C 3 2466d 2470d 0/29 closed as dup on 2019/10/23 04:39
KASAN: use-after-free Read in build_audio_procunit sound usb 19 syz, C 2 2467d 2469d 0/29 closed as dup on 2019/10/24 13:49
KMSAN: uninit-value in get_term_name sound usb 7 syz, C 2 2465d 2465d 0/29 closed as dup on 2019/10/28 13:38
▶ ▼ Discussions (3)
Title Replies (including bot) Last reply
[PATCH 4.19 000/125] 4.19.84-stable review 144 (144) 2019/11/18 14:33
[PATCH 5.3 000/193] 5.3.11-stable review 200 (200) 2019/11/12 18:26
KASAN: slab-out-of-bounds Read in build_audio_procunit 3 (4) 2019/10/28 14:42
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-out-of-bounds Read in build_audio_procunit (2) sound usb 17 syz, C 1 2455d 2455d 15/29 fixed on 2020/01/23 23:51

Sample crash report:
usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1: Product: syz
usb 1-1: Manufacturer: syz
usb 1-1: SerialNumber: syz
==================================================================
BUG: KASAN: slab-out-of-bounds in uac_extension_unit_iExtension include/uapi/linux/usb/audio.h:483 [inline]
BUG: KASAN: slab-out-of-bounds in build_audio_procunit+0xeab/0x13f0 sound/usb/mixer.c:2434
Read of size 1 at addr ffff8881d58a6549 by task kworker/1:2/83

CPU: 1 PID: 83 Comm: kworker/1:2 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xca/0x13e lib/dump_stack.c:113
 print_address_description.constprop.0+0x36/0x50 mm/kasan/report.c:374
 __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:506
 kasan_report+0xe/0x20 mm/kasan/common.c:634
 uac_extension_unit_iExtension include/uapi/linux/usb/audio.h:483 [inline]
 build_audio_procunit+0xeab/0x13f0 sound/usb/mixer.c:2434
 parse_audio_extension_unit sound/usb/mixer.c:2483 [inline]
 parse_audio_unit+0x1812/0x36f0 sound/usb/mixer.c:2761
 snd_usb_mixer_controls+0x715/0xb90 sound/usb/mixer.c:3095
 snd_usb_create_mixer+0x2b5/0x1890 sound/usb/mixer.c:3445
 usb_audio_probe+0xc76/0x2010 sound/usb/card.c:653
 usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
 really_probe+0x281/0x6d0 drivers/base/dd.c:548
 driver_probe_device+0x104/0x210 drivers/base/dd.c:721
 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
 __device_attach+0x217/0x360 drivers/base/dd.c:894
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
 device_add+0xae6/0x16f0 drivers/base/core.c:2201
 usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
 usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
 really_probe+0x281/0x6d0 drivers/base/dd.c:548
 driver_probe_device+0x104/0x210 drivers/base/dd.c:721
 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
 __device_attach+0x217/0x360 drivers/base/dd.c:894
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
 device_add+0xae6/0x16f0 drivers/base/core.c:2201
 usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536
 hub_port_connect drivers/usb/core/hub.c:5183 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5323 [inline]
 port_event drivers/usb/core/hub.c:5469 [inline]
 hub_event+0x1dd0/0x37e0 drivers/usb/core/hub.c:5551
 process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
 worker_thread+0x96/0xe20 kernel/workqueue.c:2415
 kthread+0x318/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Allocated by task 83:
 save_stack+0x1b/0x80 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc mm/kasan/common.c:510 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:483
 kmalloc include/linux/slab.h:561 [inline]
 usb_get_configuration+0x314/0x3050 drivers/usb/core/config.c:857
 usb_enumerate_device drivers/usb/core/hub.c:2369 [inline]
 usb_new_device+0xd3/0x160 drivers/usb/core/hub.c:2505
 hub_port_connect drivers/usb/core/hub.c:5183 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5323 [inline]
 port_event drivers/usb/core/hub.c:5469 [inline]
 hub_event+0x1dd0/0x37e0 drivers/usb/core/hub.c:5551
 process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
 worker_thread+0x96/0xe20 kernel/workqueue.c:2415
 kthread+0x318/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Freed by task 1:
 save_stack+0x1b/0x80 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 kasan_set_free_info mm/kasan/common.c:332 [inline]
 __kasan_slab_free+0x130/0x180 mm/kasan/common.c:471
 slab_free_hook mm/slub.c:1424 [inline]
 slab_free_freelist_hook mm/slub.c:1475 [inline]
 slab_free mm/slub.c:3018 [inline]
 kfree+0xe4/0x320 mm/slub.c:3967
 scsi_probe_and_add_lun+0x2815/0x2cd0 drivers/scsi/scsi_scan.c:1166
 __scsi_scan_target+0x273/0xc30 drivers/scsi/scsi_scan.c:1562
 scsi_scan_channel.part.0+0x126/0x1a0 drivers/scsi/scsi_scan.c:1650
 scsi_scan_channel drivers/scsi/scsi_scan.c:1677 [inline]
 scsi_scan_host_selected+0x2bb/0x3f0 drivers/scsi/scsi_scan.c:1679
 do_scsi_scan_host drivers/scsi/scsi_scan.c:1817 [inline]
 do_scsi_scan_host+0x1e8/0x260 drivers/scsi/scsi_scan.c:1807
 scsi_scan_host drivers/scsi/scsi_scan.c:1847 [inline]
 scsi_scan_host+0x37c/0x440 drivers/scsi/scsi_scan.c:1835
 virtscsi_probe+0x9b7/0xbb5 drivers/scsi/virtio_scsi.c:905
 virtio_dev_probe+0x463/0x710 drivers/virtio/virtio.c:248
 really_probe+0x281/0x6d0 drivers/base/dd.c:548
 driver_probe_device+0x104/0x210 drivers/base/dd.c:721
 device_driver_attach+0x108/0x140 drivers/base/dd.c:995
 __driver_attach+0xda/0x240 drivers/base/dd.c:1072
 bus_for_each_dev+0x14b/0x1d0 drivers/base/bus.c:304
 bus_add_driver+0x457/0x5a0 drivers/base/bus.c:621
 driver_register+0x1c4/0x330 drivers/base/driver.c:170
 __write_once_size include/linux/compiler.h:226 [inline]
 INIT_LIST_HEAD include/linux/list.h:28 [inline]
 init+0xa1/0x115 drivers/char/virtio_console.c:2251
 do_one_initcall+0xf0/0x614 init/main.c:938
 do_initcall_level init/main.c:1006 [inline]
 do_initcalls init/main.c:1014 [inline]
 do_basic_setup init/main.c:1031 [inline]
 kernel_init_freeable+0x4a9/0x596 init/main.c:1191
 kernel_init+0xd/0x1bf init/main.c:1109
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8881d58a6400
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 73 bytes to the right of
 256-byte region [ffff8881d58a6400, ffff8881d58a6500)
The buggy address belongs to the page:
page:ffffea0007562980 refcount:1 mapcount:0 mapping:ffff8881da002780 index:0x0 compound_mapcount: 0
flags: 0x200000000010200(slab|head)
raw: 0200000000010200 ffffea0007562900 0000000300000003 ffff8881da002780
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881d58a6400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881d58a6480: 00 00 00 00 00 00 00 00 05 fc fc fc fc fc fc fc
>ffff8881d58a6500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                              ^
 ffff8881d58a6580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881d58a6600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/25 21:24 https://github.com/google/kasan.git usb-fuzzer 22be26f76193 04ca72cd .config console log report syz C ci2-upstream-usb
2019/10/23 02:42 https://github.com/google/kasan.git usb-fuzzer 22be26f76193 d0686497 .config console log report syz C ci2-upstream-usb
2019/10/23 01:32 https://github.com/google/kasan.git usb-fuzzer 22be26f76193 4ee855e7 .config console log report syz C ci2-upstream-usb
2019/10/19 21:21 https://github.com/google/kasan.git usb-fuzzer 22be26f76193 8c88c9c1 .config console log report syz C ci2-upstream-usb
2019/10/31 12:37 https://github.com/google/kasan.git usb-fuzzer ff6409a6ec35 a41ca8fa .config console log report ci2-upstream-usb
2019/10/30 18:25 https://github.com/google/kasan.git usb-fuzzer ff6409a6ec35 5ea87a66 .config console log report ci2-upstream-usb
* Struck through repros no longer work on HEAD.