================================================================== 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:646 Read of size 256 at addr ffff88803a6723c0 by task syz.2.1052/11133 CPU: 0 UID: 0 PID: 11133 Comm: syz.2.1052 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:646 fbcon_init+0xda0/0x1930 drivers/video/fbdev/core/fbcon.c:1179 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+0xf2/0x150 fs/sysfs/file.c:142 kernfs_fop_write_iter+0x3af/0x570 fs/kernfs/file.c:352 iter_file_splice_write+0xa24/0x12b0 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/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa277f8f7c9 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:00007fa278dd5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fa2781e6090 RCX: 00007fa277f8f7c9 RDX: 0000000000000000 RSI: 000000000000000b RDI: 0000000000000005 RBP: 00007fa278013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa2781e6128 R14: 00007fa2781e6090 R15: 00007ffec03d3608 Allocated by task 5202: kasan_save_stack+0x33/0x60 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x25e/0x770 mm/slub.c:5270 getname_flags.part.0+0x4c/0x550 fs/namei.c:146 getname_flags include/linux/audit.h:345 [inline] getname include/linux/fs.h:2498 [inline] __do_sys_unlink fs/namei.c:5483 [inline] __se_sys_unlink fs/namei.c:5481 [inline] __x64_sys_unlink+0xb0/0x110 fs/namei.c:5481 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5202: kasan_save_stack+0x33/0x60 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x60 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:2540 [inline] slab_free mm/slub.c:6670 [inline] kmem_cache_free+0x2d8/0x770 mm/slub.c:6781 putname+0xf5/0x1a0 fs/namei.c:297 do_unlinkat+0x152/0x660 fs/namei.c:5467 __do_sys_unlink fs/namei.c:5483 [inline] __se_sys_unlink fs/namei.c:5481 [inline] __x64_sys_unlink+0xc5/0x110 fs/namei.c:5481 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803a672200 which belongs to the cache names_cache of size 4096 The buggy address is located 448 bytes inside of freed 4096-byte region [ffff88803a672200, ffff88803a673200) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3a670 head: order:3 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 ffff888140407640 ffffea0000d36c00 dead000000000002 raw: 0000000000000000 0000000000070007 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff888140407640 ffffea0000d36c00 dead000000000002 head: 0000000000000000 0000000000070007 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000e99c01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7343, tgid 7343 (syz-executor), ts 169739897322, free_ts 169709244049 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1857 prep_new_page mm/page_alloc.c:1865 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c3/0x430 mm/slub.c:3302 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4656 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] kmem_cache_alloc_noprof+0x44d/0x770 mm/slub.c:5270 getname_flags.part.0+0x4c/0x550 fs/namei.c:146 getname_flags+0x93/0xf0 include/linux/audit.h:345 getname include/linux/fs.h:2498 [inline] __do_sys_symlinkat fs/namei.c:5571 [inline] __se_sys_symlinkat fs/namei.c:5568 [inline] __x64_sys_symlinkat+0x86/0xc0 fs/namei.c:5568 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 7342 tgid 7341 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943 __folio_put+0x329/0x450 mm/swap.c:112 folio_put include/linux/mm.h:1612 [inline] put_page include/linux/mm.h:1681 [inline] put_netmem net/core/skbuff.c:7419 [inline] skb_page_unref include/linux/skbuff_ref.h:43 [inline] __skb_frag_unref include/linux/skbuff_ref.h:56 [inline] skb_release_data+0x81a/0x9e0 net/core/skbuff.c:1101 skb_release_all net/core/skbuff.c:1182 [inline] __kfree_skb+0x4f/0x70 net/core/skbuff.c:1196 tcp_wmem_free_skb include/net/tcp.h:335 [inline] tcp_rtx_queue_unlink_and_free include/net/tcp.h:2208 [inline] tcp_clean_rtx_queue net/ipv4/tcp_input.c:3494 [inline] tcp_ack+0x1d41/0x6150 net/ipv4/tcp_input.c:4119 tcp_rcv_established+0x10b6/0x36e0 net/ipv4/tcp_input.c:6374 tcp_v4_do_rcv+0xc65/0x10a0 net/ipv4/tcp_ipv4.c:1881 tcp_v4_rcv+0x3077/0x4db0 net/ipv4/tcp_ipv4.c:2324 ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:207 ip_local_deliver_finish+0x3f2/0x720 net/ipv4/ip_input.c:241 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:262 dst_input include/net/dst.h:474 [inline] ip_sublist_rcv_finish+0x2ce/0x660 net/ipv4/ip_input.c:584 ip_list_rcv_finish+0x590/0x780 net/ipv4/ip_input.c:636 ip_sublist_rcv net/ipv4/ip_input.c:644 [inline] ip_list_rcv+0x335/0x450 net/ipv4/ip_input.c:678 __netif_receive_skb_list_ptype net/core/dev.c:6182 [inline] __netif_receive_skb_list_core+0x752/0x950 net/core/dev.c:6229 __netif_receive_skb_list net/core/dev.c:6281 [inline] netif_receive_skb_list_internal+0x75f/0xdc0 net/core/dev.c:6372 Memory state around the buggy address: ffff88803a672280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803a672300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803a672380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803a672400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803a672480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================