================================================================== BUG: KASAN: slab-use-after-free in scr_memcpyw include/linux/vt_buffer.h:38 [inline] BUG: KASAN: slab-use-after-free in fbcon_prepare_logo+0xa03/0xc70 drivers/video/fbdev/core/fbcon.c:613 Read of size 14 at addr ffff888142ebf586 by task syz.6.2686/19883 CPU: 1 UID: 0 PID: 19883 Comm: syz.6.2686 Tainted: G U 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #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+0x354/0x510 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: 0033:0x7fb8fad8e969 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:00007fb8fbb88038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fb8fafb6160 RCX: 00007fb8fad8e969 RDX: 00000000fffffdef RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fb8fae10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb8fafb6160 R15: 00007ffca94aad18 Allocated by task 17655: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_node_noprof include/linux/slab.h:928 [inline] __get_vm_area_node+0x101/0x330 mm/vmalloc.c:3127 __vmalloc_node_range_noprof+0x277/0x1540 mm/vmalloc.c:3805 __vmalloc_node_noprof mm/vmalloc.c:3908 [inline] vzalloc_noprof+0x6b/0x90 mm/vmalloc.c:3981 alloc_counters net/ipv6/netfilter/ip6_tables.c:815 [inline] copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:837 [inline] get_entries net/ipv6/netfilter/ip6_tables.c:1039 [inline] do_ip6t_get_ctl+0x63f/0xa50 net/ipv6/netfilter/ip6_tables.c:1677 nf_getsockopt+0x79/0xe0 net/netfilter/nf_sockopt.c:116 ipv6_getsockopt+0x1f7/0x280 net/ipv6/ipv6_sockglue.c:1493 tcp_getsockopt+0x9e/0x100 net/ipv4/tcp.c:4727 do_sock_getsockopt+0x3ff/0x800 net/socket.c:2357 __sys_getsockopt+0x123/0x1a0 net/socket.c:2386 __do_sys_getsockopt net/socket.c:2393 [inline] __se_sys_getsockopt net/socket.c:2390 [inline] __x64_sys_getsockopt+0xbd/0x160 net/socket.c:2390 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 Freed by task 17655: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x2b6/0x4d0 mm/slub.c:4841 vfree+0x316/0x960 mm/vmalloc.c:3390 copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:882 [inline] get_entries net/ipv6/netfilter/ip6_tables.c:1039 [inline] do_ip6t_get_ctl+0x869/0xa50 net/ipv6/netfilter/ip6_tables.c:1677 nf_getsockopt+0x79/0xe0 net/netfilter/nf_sockopt.c:116 ipv6_getsockopt+0x1f7/0x280 net/ipv6/ipv6_sockglue.c:1493 tcp_getsockopt+0x9e/0x100 net/ipv4/tcp.c:4727 do_sock_getsockopt+0x3ff/0x800 net/socket.c:2357 __sys_getsockopt+0x123/0x1a0 net/socket.c:2386 __do_sys_getsockopt net/socket.c:2393 [inline] __se_sys_getsockopt net/socket.c:2390 [inline] __x64_sys_getsockopt+0xbd/0x160 net/socket.c:2390 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 The buggy address belongs to the object at ffff888142ebf580 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 6 bytes inside of freed 96-byte region [ffff888142ebf580, ffff888142ebf5e0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x142ebf flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 057ff00000000000 ffff88801b441280 ffffea0005357700 dead000000000002 raw: 0000000000000000 0000000000200020 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 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 3406779647, free_ts 3303875645 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1718 prep_new_page mm/page_alloc.c:1726 [inline] get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3688 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4970 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] __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4353 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] acpi_ut_evaluate_object+0x80/0x4a0 drivers/acpi/acpica/uteval.c:50 acpi_rs_get_method_data+0x84/0xf0 drivers/acpi/acpica/rsutils.c:650 acpi_walk_resources+0x15b/0x1e0 drivers/acpi/acpica/rsxface.c:616 acpi_mipi_check_crs_csi2+0x99/0x1d0 drivers/acpi/mipi-disco-img.c:181 acpi_bus_check_add+0x6d6/0x910 drivers/acpi/scan.c:2130 acpi_ns_walk_namespace+0x408/0x5b0 drivers/acpi/acpica/nswalk.c:233 acpi_walk_namespace drivers/acpi/acpica/nsxfeval.c:606 [inline] acpi_walk_namespace+0x110/0x130 drivers/acpi/acpica/nsxfeval.c:554 acpi_bus_scan+0x3e8/0x4a0 drivers/acpi/scan.c:2587 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2725 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_remove_cache+0x167/0x180 mm/kasan/quarantine.c:378 kmem_cache_shrink+0xd/0x20 mm/slab_common.c:558 acpi_os_purge_cache+0x15/0x20 drivers/acpi/osl.c:1605 acpi_purge_cached_objects+0x86/0x100 drivers/acpi/acpica/utxface.c:239 acpi_initialize_objects+0x47/0xa0 drivers/acpi/acpica/utxfinit.c:250 acpi_bus_init drivers/acpi/bus.c:1367 [inline] acpi_init+0x168/0xb80 drivers/acpi/bus.c:1454 do_one_initcall+0x120/0x6e0 init/main.c:1257 do_initcall_level init/main.c:1319 [inline] do_initcalls init/main.c:1335 [inline] do_basic_setup init/main.c:1354 [inline] kernel_init_freeable+0x5c2/0x900 init/main.c:1567 kernel_init+0x1c/0x2b0 init/main.c:1457 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: ffff888142ebf480: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888142ebf500: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff888142ebf580: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888142ebf600: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc ffff888142ebf680: 00 00 00 00 00 00 00 00 00 00 04 fc fc fc fc fc ==================================================================