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BUG: KASAN: stack-out-of-bounds in append_midi1_out_jack drivers/usb/gadget/function/f_midi2.c:1713 [inline]
BUG: KASAN: stack-out-of-bounds in f_midi2_create_usb_configs+0x25ac/0x4380 drivers/usb/gadget/function/f_midi2.c:1815
Write of size 1 at addr ffffc90005fa76f8 by task syz.0.23/5866

CPU: 0 UID: 0 PID: 5866 Comm: syz.0.23 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 append_midi1_out_jack drivers/usb/gadget/function/f_midi2.c:1713 [inline]
 f_midi2_create_usb_configs+0x25ac/0x4380 drivers/usb/gadget/function/f_midi2.c:1815
 f_midi2_bind+0x2690/0x2c40 drivers/usb/gadget/function/f_midi2.c:2013
 usb_add_function+0x290/0x930 drivers/usb/gadget/composite.c:333
 configfs_composite_bind+0xde0/0x1410 drivers/usb/gadget/configfs.c:1802
 gadget_bind_driver+0x2ca/0x9e0 drivers/usb/gadget/udc/core.c:1662
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __driver_attach+0x339/0x600 drivers/base/dd.c:1292
 bus_for_each_dev+0x23e/0x2c0 drivers/base/bus.c:383
 bus_add_driver+0x348/0x670 drivers/base/bus.c:763
 driver_register+0x23a/0x320 drivers/base/driver.c:174
 usb_gadget_register_driver_owner+0xf9/0x270 drivers/usb/gadget/udc/core.c:1752
 gadget_dev_desc_UDC_store+0x1c9/0x2f0 drivers/usb/gadget/configfs.c:300
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x33a/0x430 fs/configfs/file.c:229
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x61e/0xbb0 fs/read_write.c:687
 ksys_write+0x156/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe6d00ee0d9
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:00007fe6ce346028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fe6d0375fa0 RCX: 00007fe6d00ee0d9
RDX: 000000000000000b RSI: 0000200000000440 RDI: 0000000000000005
RBP: 00007fe6d0185024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe6d0376038 R14: 00007fe6d0375fa0 R15: 00007fffb51db038
 </TASK>

The buggy address belongs to stack of task syz.0.23/5866
 and is located at offset 376 in frame:
 f_midi2_bind+0x0/0x2c40 drivers/usb/gadget/function/f_midi2.c:2289

This frame has 6 objects:
 [32, 40) 'card.i'
 [64, 72) 'ump.i'
 [96, 100) 'sw.i'
 [112, 376) 'config'
 [448, 464) 'string_fn'
 [480, 496) 'strings2'

The buggy address belongs to a 8-page vmalloc region starting at 0xffffc90005fa0000 allocated at copy_process+0x820/0x4390 kernel/fork.c:2115
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x65117
memcg:ffff88802a50c482
flags: 0x80000000000000(node=0|zone=1)
raw: 0080000000000000 ffffea00019445c8 ffffea00019445c8 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff88802a50c482
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x29c2(GFP_NOWAIT|__GFP_HIGHMEM|__GFP_IO|__GFP_FS|__GFP_ZERO), pid 5863, tgid 5863 (syz.0.23), ts 103121590076, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x262a/0x26a0 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304
 alloc_pages_mpol+0xce/0x280 mm/mempolicy.c:2490
 alloc_frozen_pages_noprof mm/mempolicy.c:2561 [inline]
 alloc_pages_noprof+0xd2/0x2f0 mm/mempolicy.c:2581
 vm_area_alloc_pages mm/vmalloc.c:3689 [inline]
 __vmalloc_area_node mm/vmalloc.c:3914 [inline]
 __vmalloc_node_range_noprof+0x795/0x1730 mm/vmalloc.c:4104
 __vmalloc_node_noprof+0xc2/0x100 mm/vmalloc.c:4165
 alloc_thread_stack_node kernel/fork.c:359 [inline]
 dup_task_struct+0x2a0/0x8f0 kernel/fork.c:929
 copy_process+0x820/0x4390 kernel/fork.c:2115
 kernel_clone+0x2d2/0x8d0 kernel/fork.c:2748
 __do_sys_clone3 kernel/fork.c:3050 [inline]
 __se_sys_clone3+0x33c/0x360 kernel/fork.c:3029
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page_owner free stack trace missing

Memory state around the buggy address:
 ffffc90005fa7580: f1 f1 f1 f1 f8 f2 f2 f2 f8 f2 f2 f2 f8 f2 00 00
 ffffc90005fa7600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90005fa7680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f2
                                                                ^
 ffffc90005fa7700: f2 f2 f2 f2 f2 f2 f2 f2 00 00 f2 f2 00 00 f3 f3
 ffffc90005fa7780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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