================================================================== BUG: KASAN: use-after-free in string_nocheck lib/vsprintf.c:643 [inline] BUG: KASAN: use-after-free in string+0x20f/0x2a0 lib/vsprintf.c:725 Read of size 1 at addr ffff88810e1ebb80 by task syz.0.323/1161 CPU: 0 PID: 1161 Comm: syz.0.323 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:348 string_nocheck lib/vsprintf.c:643 [inline] string+0x20f/0x2a0 lib/vsprintf.c:725 vsnprintf+0xec5/0x1990 lib/vsprintf.c:2805 snprintf+0xe5/0x140 lib/vsprintf.c:2940 set_dev_info drivers/base/core.c:4922 [inline] dev_vprintk_emit+0x306/0x3e4 drivers/base/core.c:4932 dev_printk_emit+0xeb/0x13c drivers/base/core.c:4945 __dev_printk+0x17f/0x1b0 drivers/base/core.c:4957 _dev_err+0x11b/0x16c drivers/base/core.c:5000 raw_ioctl_ep_enable drivers/usb/gadget/legacy/raw_gadget.c:841 [inline] raw_ioctl+0x2837/0x3180 drivers/usb/gadget/legacy/raw_gadget.c:1274 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0x12f/0x1b0 fs/ioctl.c:856 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856 x64_sys_call+0x58b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f6163d9db2b 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:00007f6164c03ef0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f6164150320 RCX: 00007f6163d9db2b RDX: 00007f616415076c RSI: 0000000040095505 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6164150950 R14: 0000000000000000 R15: 00007f616415076e Allocated by task 1: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:380 [inline] __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389 kasan_kmalloc include/linux/kasan.h:212 [inline] __do_kmalloc_node mm/slab_common.c:938 [inline] __kmalloc_node_track_caller+0xb1/0x1e0 mm/slab_common.c:958 kvasprintf+0xe8/0x1a0 lib/kasprintf.c:25 kvasprintf_const+0xf2/0x240 lib/kasprintf.c:49 kobject_set_name_vargs+0x61/0x110 lib/kobject.c:265 dev_set_name+0xdf/0x130 drivers/base/core.c:3486 usb_add_gadget+0x3d4/0x620 drivers/usb/gadget/udc/core.c:1426 usb_add_gadget_udc_release drivers/usb/gadget/udc/core.c:1478 [inline] usb_add_gadget_udc+0x11a/0x150 drivers/usb/gadget/udc/core.c:1525 dummy_udc_probe+0x6e6/0x7f0 drivers/usb/gadget/udc/dummy_hcd.c:1102 platform_probe+0x16d/0x1f0 drivers/base/platform.c:1400 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2d7/0x9a0 drivers/base/dd.c:639 __driver_probe_device+0x193/0x270 drivers/base/dd.c:808 driver_probe_device+0x54/0x3e0 drivers/base/dd.c:838 __device_attach_driver+0x2e9/0x4a0 drivers/base/dd.c:966 bus_for_each_drv+0x192/0x220 drivers/base/bus.c:429 __device_attach+0x2b0/0x420 drivers/base/dd.c:1038 device_initial_probe+0x1a/0x20 drivers/base/dd.c:1087 bus_probe_device+0xc0/0x1f0 drivers/base/bus.c:489 device_add+0xb0b/0xec0 drivers/base/core.c:3698 platform_device_add+0x474/0x6d0 drivers/base/platform.c:717 dummy_hcd_init+0xc26/0x1168 drivers/usb/gadget/udc/dummy_hcd.c:2879 do_one_initcall+0x1d6/0x580 init/main.c:1433 do_initcall_level+0x174/0x2df init/main.c:1506 do_initcalls+0x50/0x92 init/main.c:1522 do_basic_setup+0x92/0x99 init/main.c:1541 kernel_init_freeable+0x2d1/0x42d init/main.c:1761 kernel_init+0x1d/0x1c0 init/main.c:1649 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Freed by task 1202: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:242 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:250 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1750 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776 slab_free mm/slub.c:3712 [inline] __kmem_cache_free+0xb7/0x1b0 mm/slub.c:3728 kfree+0x6f/0xf0 mm/slab_common.c:990 kfree_const+0x39/0x40 mm/util.c:46 kobject_cleanup lib/kobject.c:687 [inline] kobject_release lib/kobject.c:712 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x20e/0x280 lib/kobject.c:729 put_device+0x1f/0x30 drivers/base/core.c:3806 usb_put_gadget include/linux/usb/gadget.h:503 [inline] usb_del_gadget_udc+0x21/0x30 drivers/usb/gadget/udc/core.c:1576 dummy_udc_remove+0x58/0x60 drivers/usb/gadget/udc/dummy_hcd.c:1123 platform_remove+0xb8/0x110 drivers/base/platform.c:1422 device_remove drivers/base/dd.c:548 [inline] __device_release_driver drivers/base/dd.c:1283 [inline] device_release_driver_internal+0x486/0x7e0 drivers/base/dd.c:1309 device_driver_detach+0x3b/0x40 drivers/base/dd.c:1345 unbind_store+0x2e5/0x300 drivers/base/bus.c:193 drv_attr_store+0x88/0xb0 drivers/base/bus.c:77 sysfs_kf_write+0x137/0x150 fs/sysfs/file.c:136 kernfs_fop_write_iter+0x307/0x470 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2282 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x5ef/0xd00 fs/read_write.c:584 ksys_write+0x14a/0x260 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:646 x64_sys_call+0x27b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88810e1ebb80 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 0 bytes inside of 16-byte region [ffff88810e1ebb80, ffff88810e1ebb90) The buggy address belongs to the physical page: page:ffffea0004387ac0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88810e1ebf20 pfn:0x10e1eb flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea0004272dc8 ffffea000423f988 ffff888100042480 raw: ffff88810e1ebf20 000000000080007b 00000001ffffffff 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, tgid 1 (swapper/0), ts 4026938661, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2672 prep_new_page+0x1c/0x110 mm/page_alloc.c:2679 get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4586 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5930 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1967 [inline] new_slab+0x98/0x3e0 mm/slub.c:2020 ___slab_alloc+0x70f/0xb70 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] __kmem_cache_alloc_node+0x204/0x2d0 mm/slub.c:3423 __do_kmalloc_node mm/slab_common.c:937 [inline] __kmalloc_node_track_caller+0xa1/0x1e0 mm/slab_common.c:958 kvasprintf+0xe8/0x1a0 lib/kasprintf.c:25 kasprintf+0xdf/0x130 lib/kasprintf.c:59 usb_devnode+0x79/0xc0 drivers/usb/core/usb.c:590 device_get_devnode+0xbf/0x2c0 drivers/base/core.c:3983 devtmpfs_create_node+0xe3/0x250 drivers/base/devtmpfs.c:132 device_add+0xde0/0xec0 drivers/base/core.c:3669 page_owner free stack trace missing Memory state around the buggy address: ffff88810e1eba80: 00 00 fc fc 00 00 fc fc 00 04 fc fc 00 01 fc fc ffff88810e1ebb00: 00 01 fc fc 00 01 fc fc 00 05 fc fc 00 01 fc fc >ffff88810e1ebb80: fa fb fc fc 00 04 fc fc 00 07 fc fc 00 04 fc fc ^ ffff88810e1ebc00: 00 01 fc fc 00 04 fc fc 00 07 fc fc 00 04 fc fc ffff88810e1ebc80: 00 07 fc fc fa fb fc fc 00 01 fc fc 00 04 fc fc ================================================================== gadget : fail, usb_ep_enable returned -108 gadget : fail, usb_ep_enable returned -108