================================================================== 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 26 at addr ffff888034cbb6e2 by task syz.3.3934/16441 CPU: 0 UID: 0 PID: 16441 Comm: syz.3.3934 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: 0033:0x7f5a0b39c799 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:00007f5a0c259028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f5a0b615fa0 RCX: 00007f5a0b39c799 RDX: 0000000000000084 RSI: 0000200000000040 RDI: 0000000000000003 RBP: 00007f5a0b432c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5a0b616038 R14: 00007f5a0b615fa0 R15: 00007ffdd3d9fe28 Allocated by task 16437: 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 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] vmci_host_open+0x43/0x100 drivers/misc/vmw_vmci/vmci_host.c:123 misc_open+0x26d/0x450 drivers/char/misc.c:163 chrdev_open+0x234/0x6a0 fs/char_dev.c:411 do_dentry_open+0x6d8/0x1660 fs/open.c:949 vfs_open+0x82/0x3f0 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x208c/0x31a0 fs/namei.c:4830 do_file_open+0x20e/0x430 fs/namei.c:4859 do_sys_openat2+0x10d/0x1e0 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1383 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 16436: 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 vmci_host_close+0xba/0x1a0 drivers/misc/vmw_vmci/vmci_host.c:156 __fput+0x3ff/0xb40 fs/file_table.c:469 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x100/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x668/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888034cbb600 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 34 bytes to the right of allocated 192-byte region [ffff888034cbb600, ffff888034cbb6c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x34cbb flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88813fe393c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 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 9593, tgid 9593 (syz-executor), ts 236241312685, free_ts 236230183380 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] __kmalloc_cache_noprof+0x493/0x6f0 mm/slub.c:5375 kmalloc_noprof include/linux/slab.h:950 [inline] netdevice_queue_work drivers/infiniband/core/roce_gid_mgmt.c:663 [inline] netdevice_event+0x308/0x9a0 drivers/infiniband/core/roce_gid_mgmt.c:822 notifier_call_chain+0x99/0x420 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249 __netdev_upper_dev_link+0x43c/0x7e0 net/core/dev.c:8895 netdev_master_upper_dev_link+0x9f/0xd0 net/core/dev.c:8965 br_add_if+0x9fd/0x1b40 net/bridge/br_if.c:619 do_set_master+0x40f/0x730 net/core/rtnetlink.c:2963 do_setlink.isra.0+0xb2b/0x3e50 net/core/rtnetlink.c:3165 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x11bd/0x2380 net/core/rtnetlink.c:4072 page last free pid 9701 tgid 9701 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 tlb_batch_list_free mm/mmu_gather.c:161 [inline] tlb_finish_mmu+0x27d/0x810 mm/mmu_gather.c:533 exit_mmap+0x454/0xa30 mm/mmap.c:1315 __mmput+0x12a/0x410 kernel/fork.c:1175 mmput+0x67/0x80 kernel/fork.c:1198 exit_mm kernel/exit.c:581 [inline] do_exit+0x819/0x2b60 kernel/exit.c:964 do_group_exit+0xd5/0x2a0 kernel/exit.c:1118 __do_sys_exit_group kernel/exit.c:1129 [inline] __se_sys_exit_group kernel/exit.c:1127 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1127 x64_sys_call+0x102c/0x1530 arch/x86/include/generated/asm/syscalls_64.h:232 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 Memory state around the buggy address: ffff888034cbb580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888034cbb600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888034cbb680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff888034cbb700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888034cbb780: 00 00 00 04 fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================