================================================================== 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 ffff88810b6143c0 by task syz.3.77/673 CPU: 0 PID: 673 Comm: syz.3.77 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 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 seq_vprintf fs/seq_file.c:391 [inline] seq_printf+0x185/0x280 fs/seq_file.c:406 show_interrupts+0x8f9/0xa00 kernel/irq/proc.c:527 traverse+0x215/0x5e0 fs/seq_file.c:111 seq_read_iter+0xc68/0xd80 fs/seq_file.c:195 proc_reg_read_iter+0x1e0/0x2b0 fs/proc/inode.c:305 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_read+0x64b/0xb30 fs/read_write.c:796 vfs_readv fs/read_write.c:916 [inline] do_preadv+0x233/0x390 fs/read_write.c:1008 __do_sys_preadv fs/read_write.c:1058 [inline] __se_sys_preadv fs/read_write.c:1053 [inline] __x64_sys_preadv+0x9e/0xb0 fs/read_write.c:1053 x64_sys_call+0x370/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:296 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: 0033:0x7fd78899f559 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:00007fd789847028 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007fd788c26180 RCX: 00007fd78899f559 RDX: 0000000000000001 RSI: 0000200000001bc0 RDI: 0000000000000008 RBP: 00007fd788a36b20 R08: 0000000000000004 R09: 0000000000000000 R10: 000000000000ffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd788c26218 R14: 00007fd788c26180 R15: 00007fff6464a1d8 Allocated by task 24: 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 kstrdup mm/util.c:66 [inline] kstrdup_const+0x5a/0xa0 mm/util.c:89 __kernfs_new_node+0xa6/0x670 fs/kernfs/dir.c:610 kernfs_new_node+0x150/0x260 fs/kernfs/dir.c:690 kernfs_create_dir_ns+0x47/0x130 fs/kernfs/dir.c:1046 sysfs_create_dir_ns+0x128/0x290 fs/sysfs/dir.c:59 create_dir lib/kobject.c:63 [inline] kobject_add_internal+0x718/0xc20 lib/kobject.c:231 kobject_add_varg lib/kobject.c:366 [inline] kobject_add+0x165/0x230 lib/kobject.c:418 device_add+0x398/0xec0 drivers/base/core.c:3633 device_register+0x1d/0x20 drivers/base/core.c:3780 usb_create_ep_devs+0x148/0x270 drivers/usb/core/endpoint.c:169 usb_new_device+0xae3/0x1500 drivers/usb/core/hub.c:2712 hub_port_connect drivers/usb/core/hub.c:5594 [inline] hub_port_connect_change drivers/usb/core/hub.c:5734 [inline] port_event drivers/usb/core/hub.c:5898 [inline] hub_event+0x27fb/0x4310 drivers/usb/core/hub.c:5980 process_one_work+0x717/0xc30 kernel/workqueue.c:2302 worker_thread+0xa4d/0x11d0 kernel/workqueue.c:2449 kthread+0x281/0x320 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Freed by task 364: 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 kernfs_put+0x1be/0x480 fs/kernfs/dir.c:559 sysfs_put include/linux/sysfs.h:696 [inline] __kobject_del+0xea/0x2c0 lib/kobject.c:597 kobject_del+0x45/0x60 lib/kobject.c:619 device_del+0xd09/0xe50 drivers/base/core.c:3908 device_unregister+0x15/0x40 drivers/base/core.c:3929 usb_remove_ep_devs+0x50/0x80 drivers/usb/core/endpoint.c:188 usb_disconnect+0x54c/0x880 drivers/usb/core/hub.c:2358 hub_port_connect drivers/usb/core/hub.c:5433 [inline] hub_port_connect_change drivers/usb/core/hub.c:5734 [inline] port_event drivers/usb/core/hub.c:5898 [inline] hub_event+0x1a66/0x4310 drivers/usb/core/hub.c:5980 process_one_work+0x717/0xc30 kernel/workqueue.c:2302 worker_thread+0xa4d/0x11d0 kernel/workqueue.c:2449 kthread+0x281/0x320 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff88810b6143c0 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes inside of 8-byte region [ffff88810b6143c0, ffff88810b6143c8) The buggy address belongs to the physical page: page:ffffea00042d8500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10b614 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea0004653140 dead000000000002 ffff888100042300 raw: 0000000000000000 0000000000660066 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 1808637007, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2673 prep_new_page+0x1c/0x110 mm/page_alloc.c:2680 get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4587 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5931 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 kstrdup mm/util.c:66 [inline] kstrdup_const+0x5a/0xa0 mm/util.c:89 __kernfs_new_node+0xa6/0x670 fs/kernfs/dir.c:610 kernfs_new_node+0x150/0x260 fs/kernfs/dir.c:690 kernfs_create_link+0xa4/0x200 fs/kernfs/symlink.c:39 sysfs_do_create_link_sd+0x8a/0x110 fs/sysfs/symlink.c:44 sysfs_do_create_link fs/sysfs/symlink.c:80 [inline] sysfs_create_link+0x68/0x80 fs/sysfs/symlink.c:92 page_owner free stack trace missing Memory state around the buggy address: ffff88810b614280: 00 fc fc fc fc fa fc fc fc fc 05 fc fc fc fc 05 ffff88810b614300: fc fc fc fc 00 fc fc fc fc 06 fc fc fc fc fa fc >ffff88810b614380: fc fc fc 06 fc fc fc fc fa fc fc fc fc fa fc fc ^ ffff88810b614400: fc fc 06 fc fc fc fc 06 fc fc fc fc 06 fc fc fc ffff88810b614480: fc 06 fc fc fc fc 04 fc fc fc fc fa fc fc fc fc ==================================================================