Hello,
syzbot found the following crash on:
HEAD commit: d60bbfea usb: raw: add raw-gadget interface git tree: https://github.com/google/kasan.git usb-fuzzer console output: https://syzkaller.appspot.com/x/log.txt?x=132e5bcce00000 kernel config: https://syzkaller.appspot.com/x/.config?x=79de80330003b5f7 dashboard link: https://syzkaller.appspot.com/bug?extid=622d4ecb979f45c6a775 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1478c6b4e00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=117cbf8ae00000
IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+622d4ecb979f45c6a775@syzkaller.appspotmail.com
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 usb 1-1: 0:2 : does not exist ================================================================== 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 ffff8881d4aaa735 by task kworker/1:2/83
CPU: 1 PID: 83 Comm: kworker/1:2 Not tainted 5.4.0-rc6+ #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:2202 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:2202 usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2537 hub_port_connect drivers/usb/core/hub.c:5184 [inline] hub_port_connect_change drivers/usb/core/hub.c:5324 [inline] port_event drivers/usb/core/hub.c:5470 [inline] hub_event+0x1df8/0x3800 drivers/usb/core/hub.c:5552 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+0x311/0x3100 drivers/usb/core/config.c:862 usb_enumerate_device drivers/usb/core/hub.c:2370 [inline] usb_new_device+0xd3/0x160 drivers/usb/core/hub.c:2506 hub_port_connect drivers/usb/core/hub.c:5184 [inline] hub_port_connect_change drivers/usb/core/hub.c:5324 [inline] port_event drivers/usb/core/hub.c:5470 [inline] hub_event+0x1df8/0x3800 drivers/usb/core/hub.c:5552 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 211: 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:3025 [inline] kfree+0xe4/0x320 mm/slub.c:3977 do_new_mount fs/namespace.c:2827 [inline] do_mount+0x68a/0x1bf0 fs/namespace.c:3143 ksys_mount+0xd7/0x150 fs/namespace.c:3352 __do_sys_mount fs/namespace.c:3366 [inline] __se_sys_mount fs/namespace.c:3363 [inline] __x64_sys_mount+0xba/0x150 fs/namespace.c:3363 do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff8881d4aaa600 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 53 bytes to the right of 256-byte region [ffff8881d4aaa600, ffff8881d4aaa700) The buggy address belongs to the page: page:ffffea000752aa80 refcount:1 mapcount:0 mapping:ffff8881da002780 index:0x0 compound_mapcount: 0 flags: 0x200000000010200(slab|head) raw: 0200000000010200 ffffea000752c900 0000000a0000000a ffff8881da002780 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address: ffff8881d4aaa600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881d4aaa680: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc
ffff8881d4aaa700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^ ffff8881d4aaa780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881d4aaa800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================
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