Am Montag, den 10.02.2020, 17:16 -0800 schrieb syzbot: > Hello, > > syzbot found the following crash on: > > HEAD commit: e5cd56e9 usb: gadget: add raw-gadget interface > git tree: https://github.com/google/kasan.git usb-fuzzer > console output: https://syzkaller.appspot.com/x/log.txt?x=1517fed9e00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=8cff427cc8996115 > dashboard link: https://syzkaller.appspot.com/bug?extid=07efed3bc5a1407bd742 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=147026b5e00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1683b6b5e00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+07efed3bc5a1407bd742@xxxxxxxxxxxxxxxxxxxxxxxxx > > betop 0003:20BC:5500.0001: unknown main item tag 0x0 > betop 0003:20BC:5500.0001: hidraw0: USB HID v0.00 Device [HID 20bc:5500] on usb-dummy_hcd.0-1/input0 > ================================================================== > BUG: KASAN: slab-out-of-bounds in set_bit include/asm-generic/bitops/instrumented-atomic.h:28 [inline] > BUG: KASAN: slab-out-of-bounds in betopff_init drivers/hid/hid-betopff.c:99 [inline] > BUG: KASAN: slab-out-of-bounds in betop_probe+0x396/0x570 drivers/hid/hid-betopff.c:134 > Write of size 8 at addr ffff8881d4f43ac0 by task kworker/1:2/94 > > Freed by task 12: > save_stack+0x1b/0x80 mm/kasan/common.c:72 > set_track mm/kasan/common.c:80 [inline] > kasan_set_free_info mm/kasan/common.c:337 [inline] > __kasan_slab_free+0x117/0x160 mm/kasan/common.c:476 > slab_free_hook mm/slub.c:1444 [inline] > slab_free_freelist_hook mm/slub.c:1477 [inline] > slab_free mm/slub.c:3024 [inline] > kfree+0xd5/0x300 mm/slub.c:3976 > urb_destroy drivers/usb/core/urb.c:26 [inline] > kref_put include/linux/kref.h:65 [inline] > Hi, this indicates that I am confused. Why are we getting an out-of-bounds on a freed region? Is this a strange way of reporting access to already freed memory? Regards Oliver
