================================================================== BUG: KASAN: slab-out-of-bounds in scr_memcpyw include/linux/vt_buffer.h:49 [inline] BUG: KASAN: slab-out-of-bounds in fbcon_prepare_logo+0x49a/0xda0 drivers/video/fbdev/core/fbcon.c:590 Read of size 218 at addr ffff88805f9534aa by task syz.4.4051/24906 CPU: 0 PID: 24906 Comm: syz.4.4051 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x235/0x290 mm/kasan/generic.c:189 memcpy+0x25/0x60 mm/kasan/shadow.c:65 scr_memcpyw include/linux/vt_buffer.h:49 [inline] fbcon_prepare_logo+0x49a/0xda0 drivers/video/fbdev/core/fbcon.c:590 fbcon_init+0x12f1/0x2310 drivers/video/fbdev/core/fbcon.c:1121 visual_init+0x2dd/0x650 drivers/tty/vt/vt.c:1074 do_bind_con_driver+0x859/0x1030 drivers/tty/vt/vt.c:3695 vt_bind drivers/tty/vt/vt.c:3851 [inline] store_bind+0x794/0xa20 drivers/tty/vt/vt.c:3923 kernfs_fop_write_iter+0x3a8/0x500 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2179 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x748/0xd70 fs/read_write.c:594 ksys_write+0x153/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc82aa15199 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:00007fc828c6d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc82ac9cfa0 RCX: 00007fc82aa15199 RDX: 0000000000000001 RSI: 0000200000000280 RDI: 0000000000000006 RBP: 00007fc82aaac8e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc82ac9d038 R14: 00007fc82ac9cfa0 R15: 00007ffc9ab90718 Allocated by task 24906: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:612 [inline] kzalloc include/linux/slab.h:738 [inline] vc_do_resize+0x36e/0x17b0 drivers/tty/vt/vt.c:1244 fbcon_init+0x1309/0x2310 drivers/video/fbdev/core/fbcon.c:1118 visual_init+0x2dd/0x650 drivers/tty/vt/vt.c:1074 do_bind_con_driver+0x859/0x1030 drivers/tty/vt/vt.c:3695 vt_bind drivers/tty/vt/vt.c:3851 [inline] store_bind+0x794/0xa20 drivers/tty/vt/vt.c:3923 kernfs_fop_write_iter+0x3a8/0x500 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2179 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x748/0xd70 fs/read_write.c:594 ksys_write+0x153/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff88805f952000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1194 bytes to the right of 4096-byte region [ffff88805f952000, ffff88805f953000) The buggy address belongs to the page: page:ffffea00017e5400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5f950 head:ffffea00017e5400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888016c42140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4264, ts 176522486387, free_ts 173253664801 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] __kmalloc+0x11d/0x340 mm/slub.c:4408 kmalloc include/linux/slab.h:612 [inline] tomoyo_realpath_from_path+0xed/0x5e0 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x251/0x6b0 security/tomoyo/file.c:723 security_file_ioctl+0x6c/0xa0 security/security.c:1617 __do_sys_ioctl fs/ioctl.c:868 [inline] __se_sys_ioctl+0x48/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 free_slab mm/slub.c:2020 [inline] discard_slab mm/slub.c:2026 [inline] __unfreeze_partials+0x188/0x1e0 mm/slub.c:2512 put_cpu_partial+0x12d/0x190 mm/slub.c:2592 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] kmem_cache_alloc_node+0x184/0x2c0 mm/slub.c:3261 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] alloc_skb_with_frags+0xa7/0x720 net/core/skbuff.c:6209 sock_alloc_send_pskb+0x87f/0x9a0 net/core/sock.c:2535 unix_dgram_sendmsg+0x6f8/0x19c0 net/unix/af_unix.c:1809 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] __sys_sendto+0x46d/0x620 net/socket.c:2073 __do_sys_sendto net/socket.c:2085 [inline] __se_sys_sendto net/socket.c:2081 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2081 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 Memory state around the buggy address: ffff88805f953380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805f953400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805f953480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88805f953500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805f953580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 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