================================================================== BUG: KASAN: slab-out-of-bounds in scr_memcpyw include/linux/vt_buffer.h:38 [inline] BUG: KASAN: slab-out-of-bounds in fbcon_prepare_logo+0x94e/0xc60 drivers/video/fbdev/core/fbcon.c:646 Read of size 8 at addr ffff888025f9e5e8 by task syz.2.5161/19431 CPU: 1 UID: 0 PID: 19431 Comm: syz.2.5161 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:186 [inline] kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200 __asan_memcpy+0x23/0x60 mm/kasan/shadow.c:105 scr_memcpyw include/linux/vt_buffer.h:38 [inline] fbcon_prepare_logo+0x94e/0xc60 drivers/video/fbdev/core/fbcon.c:646 fbcon_init+0x10a0/0x1820 drivers/video/fbdev/core/fbcon.c:1180 visual_init+0x320/0x620 drivers/tty/vt/vt.c:1014 do_bind_con_driver.isra.0+0x636/0x9c0 drivers/tty/vt/vt.c:3962 vt_bind drivers/tty/vt/vt.c:4118 [inline] store_bind+0x609/0x730 drivers/tty/vt/vt.c:4190 dev_attr_store+0x58/0x80 drivers/base/core.c:2437 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1070 fs/read_write.c:688 ksys_write+0x12a/0x250 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd7f179c799 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:00007fd7f26ba028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fd7f1a15fa0 RCX: 00007fd7f179c799 RDX: 0000000000000084 RSI: 0000200000000040 RDI: 0000000000000003 RBP: 00007fd7f1832c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd7f1a16038 R14: 00007fd7f1a15fa0 R15: 00007ffc978336f8 Allocated by task 19430: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5260 [inline] __kmalloc_noprof+0x301/0x850 mm/slub.c:5272 kmalloc_noprof include/linux/slab.h:954 [inline] kmalloc_array_noprof include/linux/slab.h:1097 [inline] security_inode_init_security+0x113/0x370 security/security.c:1321 shmem_symlink+0x15f/0xa00 mm/shmem.c:4122 vfs_symlink fs/namei.c:5615 [inline] vfs_symlink+0x178/0x4d0 fs/namei.c:5594 filename_symlinkat+0x2a6/0x560 fs/namei.c:5640 __do_sys_symlinkat fs/namei.c:5660 [inline] __se_sys_symlinkat fs/namei.c:5655 [inline] __x64_sys_symlinkat+0x9c/0xe0 fs/namei.c:5655 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 19430: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6165 [inline] kfree+0x1f6/0x6b0 mm/slub.c:6483 security_inode_init_security+0x2bf/0x370 security/security.c:1348 shmem_symlink+0x15f/0xa00 mm/shmem.c:4122 vfs_symlink fs/namei.c:5615 [inline] vfs_symlink+0x178/0x4d0 fs/namei.c:5594 filename_symlinkat+0x2a6/0x560 fs/namei.c:5640 __do_sys_symlinkat fs/namei.c:5660 [inline] __se_sys_symlinkat fs/namei.c:5655 [inline] __x64_sys_symlinkat+0x9c/0xe0 fs/namei.c:5655 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888025f9e580 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 40 bytes to the right of allocated 64-byte region [ffff888025f9e580, ffff888025f9e5c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888025f9e780 pfn:0x25f9e flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000200 ffff88813fe398c0 ffffea0001cdee90 ffffea0001e54fd0 raw: ffff888025f9e780 000000080020001b 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 152, tgid 152 (kworker/u8:7), ts 6062537052, free_ts 6061064391 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3292 [inline] allocate_slab mm/slub.c:3481 [inline] new_slab+0xa6/0x6b0 mm/slub.c:3539 refill_objects+0x26b/0x400 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] __do_kmalloc_node mm/slub.c:5259 [inline] __kmalloc_noprof+0x688/0x850 mm/slub.c:5272 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] lsm_blob_alloc+0x68/0x90 security/security.c:192 lsm_task_alloc security/security.c:244 [inline] security_task_alloc+0x2a/0x260 security/security.c:2682 copy_process+0x258f/0x7a40 kernel/fork.c:2205 kernel_clone+0xfc/0x9a0 kernel/fork.c:2653 user_mode_thread+0xcc/0x110 kernel/fork.c:2729 call_usermodehelper_exec_work kernel/umh.c:171 [inline] call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:157 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 page last free pid 152 tgid 152 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978 __kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline] __kasan_populate_vmalloc+0x1ea/0x210 mm/kasan/shadow.c:424 kasan_populate_vmalloc include/linux/kasan.h:580 [inline] alloc_vmap_area+0x95d/0x2bd0 mm/vmalloc.c:2129 __get_vm_area_node+0x1ca/0x330 mm/vmalloc.c:3232 __vmalloc_node_range_noprof+0x213/0x1530 mm/vmalloc.c:4024 __vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4124 alloc_thread_stack_node kernel/fork.c:355 [inline] dup_task_struct kernel/fork.c:924 [inline] copy_process+0x5ec/0x7a40 kernel/fork.c:2050 kernel_clone+0xfc/0x9a0 kernel/fork.c:2653 user_mode_thread+0xcc/0x110 kernel/fork.c:2729 call_usermodehelper_exec_work kernel/umh.c:171 [inline] call_usermodehelper_exec_work+0xcb/0x180 kernel/umh.c:157 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888025f9e480: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888025f9e500: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc >ffff888025f9e580: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff888025f9e600: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc ffff888025f9e680: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ==================================================================