================================================================== 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 ffff888029386860 by task syz.2.553/8636 CPU: 1 UID: 0 PID: 8636 Comm: syz.2.553 Not tainted 6.16.0-rc5-syzkaller-00025-gd006330be3f7 #0 PREEMPT(full) 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+0xcd/0x680 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+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+0x58/0x80 drivers/base/core.c:2440 sysfs_kf_write+0xef/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x351/0x510 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6c7/0x1150 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: 0033:0x7ff12bb8e929 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:00007ff12ca36038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff12bdb5fa0 RCX: 00007ff12bb8e929 RDX: 000000000000fdef RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007ff12bc10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff12bdb5fa0 R15: 00007fff905c1398 Allocated by task 8641: 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 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4328 [inline] __kmalloc_node_track_caller_noprof+0x221/0x510 mm/slub.c:4347 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:601 __alloc_skb+0x166/0x380 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] nlmsg_new include/net/netlink.h:1041 [inline] rtmsg_ifinfo_build_skb+0x81/0x280 net/core/rtnetlink.c:4390 rtmsg_ifinfo_event net/core/rtnetlink.c:4432 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4422 [inline] rtmsg_ifinfo+0x9f/0x1a0 net/core/rtnetlink.c:4441 register_netdevice+0x1bd9/0x2270 net/core/dev.c:11157 __ip_tunnel_create+0x540/0x6e0 net/ipv4/ip_tunnel.c:268 ip_tunnel_init_net+0x22f/0x7d0 net/ipv4/ip_tunnel.c:1161 ops_init+0x1df/0x5f0 net/core/net_namespace.c:138 setup_net+0x1ff/0x510 net/core/net_namespace.c:442 copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:574 create_new_namespaces+0x3ea/0xa90 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:218 ksys_unshare+0x45b/0xa40 kernel/fork.c:3121 __do_sys_unshare kernel/fork.c:3192 [inline] __se_sys_unshare kernel/fork.c:3190 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3190 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 Freed by task 8641: 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:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4842 skb_kfree_head net/core/skbuff.c:1048 [inline] skb_free_head+0x114/0x210 net/core/skbuff.c:1060 skb_release_data+0x776/0x9c0 net/core/skbuff.c:1087 skb_release_all net/core/skbuff.c:1152 [inline] __kfree_skb net/core/skbuff.c:1166 [inline] consume_skb net/core/skbuff.c:1398 [inline] consume_skb+0xbf/0x100 net/core/skbuff.c:1392 netlink_broadcast_filtered+0x3d5/0xf10 net/netlink/af_netlink.c:1524 nlmsg_multicast_filtered include/net/netlink.h:1151 [inline] nlmsg_multicast include/net/netlink.h:1170 [inline] nlmsg_notify+0x9e/0x220 net/netlink/af_netlink.c:2577 rtnl_notify net/core/rtnetlink.c:958 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:4419 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4435 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4422 [inline] rtmsg_ifinfo+0x174/0x1a0 net/core/rtnetlink.c:4441 register_netdevice+0x1bd9/0x2270 net/core/dev.c:11157 __ip_tunnel_create+0x540/0x6e0 net/ipv4/ip_tunnel.c:268 ip_tunnel_init_net+0x22f/0x7d0 net/ipv4/ip_tunnel.c:1161 ops_init+0x1df/0x5f0 net/core/net_namespace.c:138 setup_net+0x1ff/0x510 net/core/net_namespace.c:442 copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:574 create_new_namespaces+0x3ea/0xa90 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:218 ksys_unshare+0x45b/0xa40 kernel/fork.c:3121 __do_sys_unshare kernel/fork.c:3192 [inline] __se_sys_unshare kernel/fork.c:3190 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3190 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 The buggy address belongs to the object at ffff888029386000 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 [ffff888029386000, ffff888029386800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29380 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 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842000 dead000000000100 dead000000000122 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000a4e001 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 5944, tgid 5944 (kworker/1:5), ts 101508625281, free_ts 101419006500 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_node_track_caller_noprof+0x2ee/0x510 mm/slub.c:4347 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:601 __alloc_skb+0x166/0x380 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] mld_newpack.isra.0+0x18e/0xa20 net/ipv6/mcast.c:1788 add_grhead+0x299/0x340 net/ipv6/mcast.c:1899 add_grec+0x112a/0x1680 net/ipv6/mcast.c:2037 mld_send_initial_cr.part.0+0xe2/0x260 net/ipv6/mcast.c:2282 mld_send_initial_cr net/ipv6/mcast.c:2273 [inline] mld_dad_work+0x51/0x2d0 net/ipv6/mcast.c:2308 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 page last free pid 5856 tgid 5856 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] __kmalloc_cache_noprof+0x1f1/0x3e0 mm/slub.c:4354 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] nsim_fib6_rt_create drivers/net/netdevsim/fib.c:547 [inline] nsim_fib6_rt_insert drivers/net/netdevsim/fib.c:752 [inline] nsim_fib6_event drivers/net/netdevsim/fib.c:856 [inline] nsim_fib_event drivers/net/netdevsim/fib.c:889 [inline] nsim_fib_event_work+0x17f5/0x2e80 drivers/net/netdevsim/fib.c:1493 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888029386700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888029386780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888029386800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888029386880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888029386900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================