================================================================== 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:613 Read of size 256 at addr ffff88806dabe3c0 by task syz.1.2754/18932 CPU: 1 UID: 0 PID: 18932 Comm: syz.1.2754 Tainted: G U 6.15.0-rc7-syzkaller-00144-gb1427432d3b6 #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 __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:613 fbcon_init+0xd77/0x1900 drivers/video/fbdev/core/fbcon.c:1145 visual_init+0x31d/0x620 drivers/tty/vt/vt.c:1011 do_bind_con_driver.isra.0+0x57a/0xbf0 drivers/tty/vt/vt.c:3831 vt_bind drivers/tty/vt/vt.c:3987 [inline] store_bind+0x61d/0x760 drivers/tty/vt/vt.c:4059 dev_attr_store+0x58/0x80 drivers/base/core.c:2440 sysfs_kf_write+0xef/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x351/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x5bd/0x1180 fs/read_write.c:684 ksys_write+0x12a/0x240 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1414d8e969 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:00007f1415c03038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f1414fb6160 RCX: 00007f1414d8e969 RDX: 00000000fffffdef RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f1414e10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f1414fb6160 R15: 00007ffe5f568f68 The buggy address belongs to the object at ffff88806dabe370 which belongs to the cache hugetlbfs_inode_cache of size 1168 The buggy address is located 80 bytes inside of allocated 1168-byte region [ffff88806dabe370, ffff88806dabe800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6dabc head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888034f2d281 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff888022ecda00 dead000000000122 0000000000000000 raw: 0000000000000000 00000000800c000c 00000000f5000000 ffff888034f2d281 head: 00fff00000000040 ffff888022ecda00 dead000000000122 0000000000000000 head: 0000000000000000 00000000800c000c 00000000f5000000 ffff888034f2d281 head: 00fff00000000002 ffffea0001b6af01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 18811, tgid 18807 (syz.3.2728), ts 790857464541, free_ts 789987471715 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1714 prep_new_page mm/page_alloc.c:1722 [inline] get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3684 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4966 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2450 [inline] allocate_slab mm/slub.c:2618 [inline] new_slab+0x244/0x340 mm/slub.c:2672 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3858 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3948 __slab_alloc_node mm/slub.c:4023 [inline] slab_alloc_node mm/slub.c:4184 [inline] kmem_cache_alloc_lru_noprof+0xf4/0x3b0 mm/slub.c:4215 hugetlbfs_alloc_inode+0x8c/0x1d0 fs/hugetlbfs/inode.c:1200 alloc_inode+0x61/0x240 fs/inode.c:346 new_inode+0x22/0x1c0 fs/inode.c:1145 hugetlbfs_get_inode+0x354/0x730 fs/hugetlbfs/inode.c:937 hugetlb_file_setup+0x15b/0x620 fs/hugetlbfs/inode.c:1554 ksys_mmap_pgoff+0x189/0x5c0 mm/mmap.c:599 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 page last free pid 14670 tgid 14670 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1258 [inline] __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2721 vfree+0x176/0x960 mm/vmalloc.c:3384 prealloc_destroy kernel/bpf/hashtab.c:362 [inline] htab_map_free+0x85f/0xab0 kernel/bpf/hashtab.c:1544 bpf_map_free kernel/bpf/syscall.c:861 [inline] bpf_map_free_deferred+0x1c7/0x410 kernel/bpf/syscall.c:887 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88806dabe280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88806dabe300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88806dabe380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88806dabe400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88806dabe480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================