================================================================== BUG: KASAN: slab-use-after-free in string_nocheck lib/vsprintf.c:648 [inline] BUG: KASAN: slab-use-after-free in string+0x216/0x2d0 lib/vsprintf.c:730 Read of size 1 at addr ffff888029cd1a20 by task syz.0.1294/9857 CPU: 0 UID: 0 PID: 9857 Comm: syz.0.1294 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: 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 string_nocheck lib/vsprintf.c:648 [inline] string+0x216/0x2d0 lib/vsprintf.c:730 vsnprintf+0x74a/0xef0 lib/vsprintf.c:2945 snprintf+0xe8/0x140 lib/vsprintf.c:3043 set_dev_info drivers/base/core.c:4984 [inline] dev_vprintk_emit+0x30f/0x400 drivers/base/core.c:4994 dev_printk_emit+0xee/0x140 drivers/base/core.c:5007 _dev_err+0x11e/0x180 drivers/base/core.c:5062 raw_process_ep_io+0x7d2/0xd80 drivers/usb/gadget/legacy/raw_gadget.c:1116 raw_ioctl_ep_write drivers/usb/gadget/legacy/raw_gadget.c:1153 [inline] raw_ioctl+0x251c/0x41c0 drivers/usb/gadget/legacy/raw_gadget.c:1325 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 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: 0033:0x7fd60499dd6b 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:00007fd60580ef60 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007fd60499dd6b RDX: 00007fd60580efe0 RSI: 0000000040085507 RDI: 0000000000000006 RBP: 0000000000000006 R08: 00007fd604d50320 R09: 0000000000000000 R10: 0000000000000006 R11: 0000000000000246 R12: 0000200000000080 R13: 0000000000000000 R14: 00007fd604c25fa0 R15: 00007ffc006c9b88 Allocated by task 1: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5334 [inline] __kmalloc_node_track_caller_noprof+0x4c3/0x730 mm/slub.c:5471 kvasprintf+0xeb/0x1a0 lib/kasprintf.c:25 kobject_set_name_vargs+0x61/0x110 lib/kobject.c:274 dev_set_name+0xe2/0x140 drivers/base/core.c:3560 usb_add_gadget+0x475/0x700 drivers/usb/gadget/udc/core.c:1459 usb_add_gadget_udc_release+0x19c/0x1f0 drivers/usb/gadget/udc/core.c:1517 dummy_udc_probe+0x6b1/0x7b0 drivers/usb/gadget/udc/dummy_hcd.c:1121 platform_probe+0xf9/0x190 drivers/base/platform.c:1439 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 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500 __device_attach+0x2c4/0x450 drivers/base/dd.c:1098 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153 bus_probe_device+0x12a/0x220 drivers/base/bus.c:620 device_add+0x7d7/0xb80 drivers/base/core.c:3772 platform_device_add+0x4bd/0x860 drivers/base/platform.c:762 dummy_hcd_init+0x966/0xd00 drivers/usb/gadget/udc/dummy_hcd.c:2894 do_one_initcall+0x250/0x870 init/main.c:1347 do_initcall_level+0x10a/0x1a0 init/main.c:1409 do_initcalls+0x59/0xa0 init/main.c:1425 kernel_init_freeable+0x29d/0x3e0 init/main.c:1658 kernel_init+0x1d/0x1d0 init/main.c:1548 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 9866: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2677 [inline] slab_free mm/slub.c:6377 [inline] kfree+0x1c5/0x640 mm/slub.c:6692 kobject_cleanup lib/kobject.c:695 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x267/0x550 lib/kobject.c:737 device_remove drivers/base/dd.c:616 [inline] __device_release_driver drivers/base/dd.c:1349 [inline] device_release_driver_internal+0x48b/0x880 drivers/base/dd.c:1372 unbind_store+0x1a1/0x1d0 drivers/base/bus.c:244 kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 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 The buggy address belongs to the object at ffff888029cd1a20 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 0 bytes inside of freed 16-byte region [ffff888029cd1a20, ffff888029cd1a30) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29cd1 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b004640 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800800080 00000000f5000000 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 9998438126, 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+0x21fa/0x2270 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3266 [inline] allocate_slab+0x79/0x5e0 mm/slub.c:3380 new_slab mm/slub.c:3426 [inline] refill_objects+0x2d5/0x350 mm/slub.c:7310 refill_sheaf mm/slub.c:2804 [inline] __pcs_replace_empty_main+0x2bf/0x6b0 mm/slub.c:4675 alloc_from_pcs mm/slub.c:4773 [inline] slab_alloc_node mm/slub.c:4905 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kmalloc_node_track_caller_noprof+0x557/0x730 mm/slub.c:5471 __kmemdup_nul mm/util.c:64 [inline] kstrdup+0x42/0x100 mm/util.c:84 __kernfs_new_node+0xa9/0x980 fs/kernfs/dir.c:661 kernfs_new_node fs/kernfs/dir.c:751 [inline] kernfs_create_dir_ns+0xfe/0x230 fs/kernfs/dir.c:1120 sysfs_create_dir_ns+0x12f/0x2a0 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x622/0xcd0 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_add+0x163/0x240 lib/kobject.c:426 device_add+0x3fa/0xb80 drivers/base/core.c:3695 platform_device_add+0x4bd/0x860 drivers/base/platform.c:762 dummy_hcd_init+0x667/0xd00 drivers/usb/gadget/udc/dummy_hcd.c:2873 page_owner free stack trace missing Memory state around the buggy address: ffff888029cd1900: 00 04 fc fc 00 04 fc fc 00 04 fc fc 00 04 fc fc ffff888029cd1980: 00 04 fc fc 00 04 fc fc 00 00 fc fc fa fb fc fc >ffff888029cd1a00: 00 01 fc fc fa fb fc fc 00 00 fc fc fa fb fc fc ^ ffff888029cd1a80: fa fb fc fc fa fb fc fc 00 00 fc fc fa fb fc fc ffff888029cd1b00: 00 00 fc fc 00 00 fc fc 00 04 fc fc 00 04 fc fc ==================================================================