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BUG: KASAN: global-out-of-bounds in usb_copy_descriptors+0x1b8/0x320
Read of size 128 at addr ffffffff9ab18580 by task syz.5.3355/14247

CPU: 0 UID: 0 PID: 14247 Comm: syz.5.3355 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_address_description+0x55/0x1e0
 print_report+0x58/0x70
 kasan_report+0x117/0x150
 kasan_check_range+0x264/0x2c0
 __asan_memcpy+0x29/0x70
 usb_copy_descriptors+0x1b8/0x320
 usb_assign_descriptors+0xcf/0x290
 f_audio_bind+0x1b5e/0x34b0
 usb_add_function+0x2e1/0x9f0
 configfs_composite_bind+0xde0/0x1410
 gadget_bind_driver+0x2ca/0x9e0
 really_probe+0x254/0xae0
 __driver_probe_device+0x1e8/0x360
 driver_probe_device+0x4f/0x240
 __driver_attach+0x339/0x600
 bus_for_each_dev+0x23b/0x2c0
 bus_add_driver+0x345/0x670
 driver_register+0x23a/0x320
 usb_gadget_register_driver_owner+0xf9/0x270
 gadget_dev_desc_UDC_store+0x1c9/0x2f0
 configfs_write_iter+0x337/0x430
 vfs_write+0x612/0xba0
 ksys_write+0x150/0x270
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff917d9e019
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff918be6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff918025fa0 RCX: 00007ff917d9e019
RDX: 000000000000000c RSI: 0000200000001f00 RDI: 0000000000000004
RBP: 00007ff917e3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff918026038 R14: 00007ff918025fa0 R15: 00007ffdec988858
 </TASK>

The buggy address belongs to the variable:
 ac_header_desc+0x0/0x20

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1ab18
flags: 0xfff00000002000(reserved|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002000 ffffea00006ac608 ffffea00006ac608 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffffffff9ab18480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffff9ab18500: 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9
>ffffffff9ab18580: 00 f9 f9 f9 00 f9 f9 f9 00 f9 f9 f9 00 00 f9 f9
                      ^
 ffffffff9ab18600: 00 00 f9 f9 00 00 f9 f9 00 00 f9 f9 00 00 00 00
 ffffffff9ab18680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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