==================================================================
BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:646 [inline]
BUG: KASAN: slab-use-after-free in string+0x20f/0x2b0 lib/vsprintf.c:728
Read of size 1 at addr ffff888105fb5a20 by task syz.0.84/525

CPU: 0 UID: 0 PID: 525 Comm: syz.0.84 Not tainted syzkaller #0 7f3b23dcf55806c758f3cdeb9210fc77c27c120f
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 print_address_description+0x71/0x210 mm/kasan/report.c:377
 print_report+0x4a/0x70 mm/kasan/report.c:481
 kasan_report+0x162/0x1a0 mm/kasan/report.c:594
 __asan_report_load1_noabort+0x18/0x20 mm/kasan/report_generic.c:378
 string_nocheck lib/vsprintf.c:646 [inline]
 string+0x20f/0x2b0 lib/vsprintf.c:728
 vsnprintf+0xe65/0x1ad0 lib/vsprintf.c:2803
 snprintf+0xe9/0x140 lib/vsprintf.c:2938
 set_dev_info drivers/base/core.c:4950 [inline]
 dev_vprintk_emit+0x313/0x400 drivers/base/core.c:4960
 dev_printk_emit+0xef/0x150 drivers/base/core.c:4973
 __dev_printk+0x17f/0x1b0 drivers/base/core.c:4985
 _dev_err+0x11f/0x180 drivers/base/core.c:5028
 raw_process_ep0_io+0x54b/0x7a0 drivers/usb/gadget/legacy/raw_gadget.c:730
 raw_ioctl_ep0_write drivers/usb/gadget/legacy/raw_gadget.c:767 [inline]
 raw_ioctl+0x226c/0x37a0 drivers/usb/gadget/legacy/raw_gadget.c:1313
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0x132/0x1b0 fs/ioctl.c:893
 __x64_sys_ioctl+0x7f/0xa0 fs/ioctl.c:893
 x64_sys_call+0x1878/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f5ea999dcab
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007f5eaa7e1f50 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f5ea999dcab
RDX: 00007f5eaa7e1fd0 RSI: 0000000040085503 RDI: 0000000000000003
RBP: 00007f5eaa7e1fd0 R08: 0000000000000004 R09: 0000000000000409
R10: 0000000000000003 R11: 0000000000000246 R12: 00007f5eaa7e1fd8
R13: 0000200000000600 R14: 00007f5ea9c25fa0 R15: 00007fff10a88228
 </TASK>

Allocated by task 1:
 kasan_save_stack mm/kasan/common.c:49 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
 kasan_save_alloc_info+0x3a/0x50 mm/kasan/generic.c:565
 poison_kmalloc_redzone mm/kasan/common.c:379 [inline]
 __kasan_kmalloc+0x96/0xb0 mm/kasan/common.c:396
 kasan_kmalloc include/linux/kasan.h:261 [inline]
 __do_kmalloc_node mm/slub.c:4395 [inline]
 __kmalloc_node_track_caller_noprof+0x24e/0x4f0 mm/slub.c:4414
 kvasprintf+0xf1/0x260 lib/kasprintf.c:25
 kvasprintf_const+0xf6/0x250 lib/kasprintf.c:49
 kobject_set_name_vargs+0x65/0x120 lib/kobject.c:274
 dev_set_name+0xe3/0x140 drivers/base/core.c:3495
 usb_add_gadget+0x436/0x780 drivers/usb/gadget/udc/core.c:1446
 usb_add_gadget_udc_release drivers/usb/gadget/udc/core.c:1504 [inline]
 usb_add_gadget_udc+0x11e/0x160 drivers/usb/gadget/udc/core.c:1551
 dummy_udc_probe+0x6ea/0x7f0 drivers/usb/gadget/udc/dummy_hcd.c:1102
 platform_probe+0x17a/0x200 drivers/base/platform.c:1404
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x2e1/0x8b0 drivers/base/dd.c:657
 __driver_probe_device+0x193/0x280 drivers/base/dd.c:799
 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829
 __device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957
 bus_for_each_drv+0x264/0x300 drivers/base/bus.c:459
 __device_attach+0x2c4/0x3c0 drivers/base/dd.c:1029
 device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078
 bus_probe_device+0x18b/0x270 drivers/base/bus.c:534
 device_add+0x7fd/0xbf0 drivers/base/core.c:3692
 platform_device_add+0x464/0x6c0 drivers/base/platform.c:716
 dummy_hcd_init+0xce2/0x1230 drivers/usb/gadget/udc/dummy_hcd.c:2876
 do_one_initcall+0x1e8/0x6a0 init/main.c:1406
 do_initcall_level+0x174/0x2e5 init/main.c:1468
 do_initcalls+0x7e/0x160 init/main.c:1484
 do_basic_setup+0x95/0xb0 init/main.c:1503
 kernel_init_freeable+0x2b1/0x400 init/main.c:1717
 kernel_init+0x21/0x1e0 init/main.c:1606
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 519:
 kasan_save_stack mm/kasan/common.c:49 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
 kasan_save_free_info+0x44/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:249 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:266
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2445 [inline]
 slab_free mm/slub.c:4714 [inline]
 kfree+0x158/0x440 mm/slub.c:4875
 kfree_const+0x3d/0x50 mm/util.c:49
 kobject_cleanup lib/kobject.c:695 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x21f/0x2a0 lib/kobject.c:737
 put_device+0x23/0x40 drivers/base/core.c:3800
 usb_put_gadget include/linux/usb/gadget.h:512 [inline]
 usb_del_gadget_udc+0x25/0x30 drivers/usb/gadget/udc/core.c:1594
 dummy_udc_remove+0x5c/0x70 drivers/usb/gadget/udc/dummy_hcd.c:1123
 platform_remove+0x7e/0xb0 drivers/base/platform.c:1424
 device_remove drivers/base/dd.c:567 [inline]
 __device_release_driver drivers/base/dd.c:1272 [inline]
 device_release_driver_internal+0x4ad/0x830 drivers/base/dd.c:1295
 device_driver_detach+0x3f/0x50 drivers/base/dd.c:1331
 unbind_store+0x1ab/0x1f0 drivers/base/bus.c:244
 drv_attr_store+0x91/0xb0 drivers/base/bus.c:125
 sysfs_kf_write+0x141/0x160 fs/sysfs/file.c:136
 kernfs_fop_write_iter+0x319/0x510 fs/kernfs/file.c:352
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x762/0xfd0 fs/read_write.c:684
 ksys_write+0x145/0x260 fs/read_write.c:737
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __x64_sys_write+0x7f/0x90 fs/read_write.c:746
 x64_sys_call+0x271c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

The buggy address belongs to the object at ffff888105fb5a20
 which belongs to the cache kmalloc-16 of size 16
The buggy address is located 0 bytes inside of
 freed 16-byte region [ffff888105fb5a20, ffff888105fb5a30)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x105fb5
flags: 0x4000000000000000(zone=1)
page_type: f5(slab)
raw: 4000000000000000 ffff888100041640 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000800080 00000001f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 4182987316, free_ts 0
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook+0x37d/0x3b0 mm/page_alloc.c:1863
 prep_new_page+0x2d/0x180 mm/page_alloc.c:1871
 get_page_from_freelist+0x4aea/0x4ba0 mm/page_alloc.c:3948
 __alloc_pages_noprof+0x35a/0x7e0 mm/page_alloc.c:5315
 alloc_slab_page+0x6b/0x1e0 mm/slub.c:-1
 allocate_slab+0x69/0x430 mm/slub.c:2687
 new_slab mm/slub.c:2741 [inline]
 ___slab_alloc+0x591/0x8c0 mm/slub.c:3934
 __slab_alloc mm/slub.c:4025 [inline]
 __slab_alloc_node mm/slub.c:4078 [inline]
 slab_alloc_node mm/slub.c:4239 [inline]
 __do_kmalloc_node mm/slub.c:4394 [inline]
 __kmalloc_node_track_caller_noprof+0x2e3/0x4f0 mm/slub.c:4414
 kstrdup+0x4d/0x130 mm/util.c:70
 kstrdup_const+0x45/0x60 mm/util.c:93
 __kernfs_new_node+0xaa/0x740 fs/kernfs/dir.c:624
 kernfs_new_node+0x154/0x280 fs/kernfs/dir.c:704
 kernfs_create_link+0xa8/0x200 fs/kernfs/symlink.c:39
 sysfs_do_create_link_sd+0x8a/0x120 fs/sysfs/symlink.c:44
 sysfs_do_create_link fs/sysfs/symlink.c:80 [inline]
 sysfs_create_link+0x6c/0x90 fs/sysfs/symlink.c:92
 bus_add_device+0x2a0/0x430 drivers/base/bus.c:499
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888105fb5900: 00 05 fc fc 00 05 fc fc 00 04 fc fc 00 01 fc fc
 ffff888105fb5980: fa fb fc fc fa fb fc fc 00 00 fc fc 00 01 fc fc
>ffff888105fb5a00: 00 01 fc fc fa fb fc fc fa fb fc fc 00 04 fc fc
                               ^
 ffff888105fb5a80: 00 01 fc fc 00 04 fc fc 00 00 fc fc 00 00 fc fc
 ffff888105fb5b00: 00 05 fc fc fa fb fc fc 00 01 fc fc 00 01 fc fc
==================================================================
gadget �|4����: fail, usb_ep_queue returned -108
UDC core: USB Raw Gadget: couldn't find an available UDC or it's busy
misc raw-gadget: fail, usb_gadget_register_driver returned -16