================================================================== 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+0xa03/0xc70 drivers/video/fbdev/core/fbcon.c:623 Read of size 256 at addr ffff8880233fa3c0 by task syz.1.1190/12470 CPU: 1 UID: 0 PID: 12470 Comm: syz.1.1190 Tainted: G U syzkaller #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:194 [inline] kasan_check_range+0x100/0x1b0 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+0xa03/0xc70 drivers/video/fbdev/core/fbcon.c:623 fbcon_init+0xd77/0x1900 drivers/video/fbdev/core/fbcon.c:1156 visual_init+0x320/0x620 drivers/tty/vt/vt.c:1020 do_bind_con_driver.isra.0+0x57a/0xbf0 drivers/tty/vt/vt.c:3960 vt_bind drivers/tty/vt/vt.c:4116 [inline] store_bind+0x61d/0x760 drivers/tty/vt/vt.c:4188 dev_attr_store+0x58/0x80 drivers/base/core.c:2437 sysfs_kf_write+0xef/0x150 fs/sysfs/file.c:142 kernfs_fop_write_iter+0x3ac/0x570 fs/kernfs/file.c:352 iter_file_splice_write+0xa21/0x12e0 fs/splice.c:738 do_splice_from fs/splice.c:938 [inline] direct_splice_actor+0x192/0x6c0 fs/splice.c:1161 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1105 do_splice_direct_actor fs/splice.c:1204 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1230 do_sendfile+0xb06/0xe50 fs/read_write.c:1370 __do_sys_sendfile64 fs/read_write.c:1431 [inline] __se_sys_sendfile64 fs/read_write.c:1417 [inline] __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1417 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe46d38eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe46e1c7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fe46d5e5fa0 RCX: 00007fe46d38eec9 RDX: 0000000000000000 RSI: 0000000000000026 RDI: 0000000000000003 RBP: 00007fe46d411f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe46d5e6038 R14: 00007fe46d5e5fa0 R15: 00007ffc47675d38 Allocated by task 12305: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4946 [inline] slab_alloc_node mm/slub.c:5245 [inline] kmem_cache_alloc_noprof+0x250/0x6e0 mm/slub.c:5252 mt_alloc_one lib/maple_tree.c:172 [inline] mas_alloc_nodes lib/maple_tree.c:1108 [inline] mas_preallocate+0xe6a/0x11f0 lib/maple_tree.c:5192 vma_iter_prealloc mm/vma.h:442 [inline] __split_vma+0x34a/0x1070 mm/vma.c:528 split_vma mm/vma.c:598 [inline] vma_modify+0xee1/0x2030 mm/vma.c:1631 vma_modify_flags+0x212/0x2d0 mm/vma.c:1649 mprotect_fixup+0x1df/0xb40 mm/mprotect.c:816 do_mprotect_pkey+0x9bc/0xd40 mm/mprotect.c:990 __do_sys_mprotect mm/mprotect.c:1011 [inline] __se_sys_mprotect mm/mprotect.c:1008 [inline] __x64_sys_mprotect+0x78/0xc0 mm/mprotect.c:1008 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2514 [inline] __rcu_free_sheaf_prepare+0x52/0x300 mm/slub.c:2720 rcu_free_sheaf+0x1a/0xa0 mm/slub.c:6139 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0x799/0x1530 kernel/rcu/tree.c:2861 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622 run_ksoftirqd kernel/softirq.c:1063 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:1055 smpboot_thread_fn+0x3f4/0xae0 kernel/smpboot.c:160 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff8880233fa200 which belongs to the cache maple_node of size 256 The buggy address is located 192 bytes to the right of allocated 256-byte region [ffff8880233fa200, ffff8880233fa300) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x233fa head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ffb0c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813ffb0c80 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffea00008cfe81 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x52800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP), pid 26, tgid 26 (kdevtmpfs), ts 14763583318, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3030 [inline] allocate_slab mm/slub.c:3203 [inline] new_slab+0x24a/0x360 mm/slub.c:3257 ___slab_alloc+0xdc4/0x1ae0 mm/slub.c:4627 __kmem_cache_alloc_bulk+0x225/0x770 mm/slub.c:7330 refill_sheaf mm/slub.c:2608 [inline] kmem_cache_prefill_sheaf+0x1c3/0x420 mm/slub.c:5372 mt_get_sheaf lib/maple_tree.c:187 [inline] mas_alloc_nodes lib/maple_tree.c:1138 [inline] mas_wr_preallocate lib/maple_tree.c:3950 [inline] mas_insert lib/maple_tree.c:3983 [inline] mas_alloc_cyclic+0x14cc/0x1a80 lib/maple_tree.c:4046 mtree_alloc_cyclic+0x169/0x1d0 lib/maple_tree.c:6090 simple_offset_add+0xbf/0x180 fs/libfs.c:297 shmem_mknod+0x26b/0x450 mm/shmem.c:3853 vfs_mknod+0x5d7/0x8e0 fs/namei.c:4322 handle_create drivers/base/devtmpfs.c:233 [inline] handle drivers/base/devtmpfs.c:385 [inline] devtmpfs_work_loop+0x1b7/0xce0 drivers/base/devtmpfs.c:400 devtmpfsd+0x4c/0x50 drivers/base/devtmpfs.c:442 kthread+0x3c2/0x780 kernel/kthread.c:463 page_owner free stack trace missing Memory state around the buggy address: ffff8880233fa280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880233fa300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880233fa380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880233fa400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880233fa480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================