================================================================== 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:618 Read of size 256 at addr ffff8880331da860 by task syz.0.17/5996 CPU: 0 UID: 0 PID: 5996 Comm: syz.0.17 Not tainted 6.16.0-syzkaller-04405-g4b290aae788e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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:183 [inline] kasan_check_range+0x100/0x1b0 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:618 fbcon_init+0xd77/0x1900 drivers/video/fbdev/core/fbcon.c:1150 visual_init+0x31d/0x620 drivers/tty/vt/vt.c:1019 do_bind_con_driver.isra.0+0x57a/0xbf0 drivers/tty/vt/vt.c:3915 vt_bind drivers/tty/vt/vt.c:4071 [inline] store_bind+0x61d/0x760 drivers/tty/vt/vt.c:4143 dev_attr_store+0x55/0x80 drivers/base/core.c:2437 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:593 [inline] vfs_write+0x6c4/0x1150 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f580578e9a9 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:00007ffce73cfbb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f58059b5fa0 RCX: 00007f580578e9a9 RDX: 0000000000000081 RSI: 00002000000001c0 RDI: 0000000000000004 RBP: 00007f5805810d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f58059b5fa0 R14: 00007f58059b5fa0 R15: 0000000000000003 The buggy address belongs to the object at ffff8880331da000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 96 bytes to the right of allocated 2048-byte region [ffff8880331da000, ffff8880331da800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x331d8 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 ffff88801b842000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842000 dead000000000122 0000000000000000 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000cc7601 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5996, tgid 5996 (syz.0.17), ts 103546222970, free_ts 103072976762 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab mm/slub.c:2619 [inline] new_slab+0x23b/0x330 mm/slub.c:2673 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949 __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4340 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] vc_do_resize+0x1de/0x10e0 drivers/tty/vt/vt.c:1182 vc_resize include/linux/vt_kern.h:49 [inline] fbcon_startup+0x427/0xba0 drivers/video/fbdev/core/fbcon.c:1001 do_bind_con_driver.isra.0+0x20a/0xbf0 drivers/tty/vt/vt.c:3878 vt_bind drivers/tty/vt/vt.c:4071 [inline] store_bind+0x61d/0x760 drivers/tty/vt/vt.c:4143 dev_attr_store+0x55/0x80 drivers/base/core.c:2437 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:593 [inline] vfs_write+0x6c4/0x1150 fs/read_write.c:686 page last free pid 5947 tgid 5947 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_noprof+0x1d4/0x510 mm/slub.c:4340 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x14c/0x870 net/ipv6/route.c:3811 ip6_route_add.part.0+0x22/0x1d0 net/ipv6/route.c:3940 ip6_route_add+0x45/0x60 net/ipv6/route.c:3937 addrconf_prefix_route+0x2fd/0x510 net/ipv6/addrconf.c:2487 inet6_addr_add+0x589/0x960 net/ipv6/addrconf.c:3052 inet6_rtm_newaddr+0x1619/0x1c70 net/ipv6/addrconf.c:5058 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x58a/0x850 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896 Memory state around the buggy address: ffff8880331da700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880331da780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880331da800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880331da880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880331da900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================