================================================================== 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+0x94e/0xc60 drivers/video/fbdev/core/fbcon.c:686 Read of size 26 at addr ffff8880339c07ea by task syz.0.1668/11003 CPU: 1 UID: 0 PID: 11003 Comm: syz.0.1668 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:186 [inline] kasan_check_range+0x10f/0x1e0 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+0x94e/0xc60 drivers/video/fbdev/core/fbcon.c:686 fbcon_init+0x1065/0x1830 drivers/video/fbdev/core/fbcon.c:1228 visual_init+0x320/0x620 drivers/tty/vt/vt.c:1048 do_bind_con_driver.isra.0+0x636/0x9c0 drivers/tty/vt/vt.c:4056 vt_bind drivers/tty/vt/vt.c:4212 [inline] store_bind+0x609/0x730 drivers/tty/vt/vt.c:4284 dev_attr_store+0x58/0x80 drivers/base/core.c:2437 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352 iter_file_splice_write+0x830/0x10a0 fs/splice.c:736 do_splice_from fs/splice.c:936 [inline] direct_splice_actor+0x192/0x6c0 fs/splice.c:1159 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103 do_splice_direct_actor fs/splice.c:1202 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1228 do_sendfile+0xadc/0xe20 fs/read_write.c:1372 __do_sys_sendfile64 fs/read_write.c:1433 [inline] __se_sys_sendfile64 fs/read_write.c:1419 [inline] __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1419 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faf3279ce59 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:00007faf335a6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007faf32a15fa0 RCX: 00007faf3279ce59 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000007 RBP: 00007faf32832d6f R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000000 R13: 00007faf32a16038 R14: 00007faf32a15fa0 R15: 00007ffdd9083958 Allocated by task 10276: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5296 [inline] __kmalloc_noprof+0x301/0x850 mm/slub.c:5308 kmalloc_noprof include/linux/slab.h:954 [inline] memcg_init_list_lru_one mm/list_lru.c:411 [inline] memcg_list_lru_alloc+0x4ec/0x740 mm/list_lru.c:544 __memcg_slab_post_alloc_hook+0x27e/0xff0 mm/memcontrol.c:3463 memcg_slab_post_alloc_hook mm/slub.c:2461 [inline] slab_post_alloc_hook mm/slub.c:4581 [inline] slab_alloc_node mm/slub.c:4899 [inline] kmem_cache_alloc_lru_noprof+0x592/0x6e0 mm/slub.c:4918 ext4_alloc_inode+0x26/0x650 fs/ext4/super.c:1400 alloc_inode+0x68/0x250 fs/inode.c:345 iget_locked+0x1d9/0x6d0 fs/inode.c:1474 __ext4_iget+0x3da/0x46d0 fs/ext4/inode.c:5249 ext4_lookup+0x37c/0x730 fs/ext4/namei.c:1785 __lookup_slow+0x251/0x460 fs/namei.c:1915 lookup_slow+0x50/0x70 fs/namei.c:1932 walk_component fs/namei.c:2278 [inline] link_path_walk+0x1377/0x1cc0 fs/namei.c:2652 path_openat+0x1be/0x31a0 fs/namei.c:4854 do_file_open_root+0x2f6/0x5a0 fs/namei.c:4911 file_open_root+0x19b/0x3b0 fs/open.c:1351 kernel_read_file_from_path_initns+0x189/0x260 fs/kernel_read_file.c:163 fw_get_filesystem_firmware drivers/base/firmware_loader/main.c:549 [inline] _request_firmware+0x733/0x13c0 drivers/base/firmware_loader/main.c:873 request_firmware+0x35/0x50 drivers/base/firmware_loader/main.c:948 reg_reload_regdb+0x85/0x460 net/wireless/reg.c:1067 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2555 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1899 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2752 __sys_sendmsg+0x170/0x220 net/socket.c:2784 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880339c0700 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 42 bytes to the right of allocated 192-byte region [ffff8880339c0700, ffff8880339c07c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x339c0 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88813fe303c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 18955962341, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1853 prep_new_page mm/page_alloc.c:1861 [inline] get_page_from_freelist+0x11a6/0x3410 mm/page_alloc.c:3941 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5221 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab mm/slub.c:3467 [inline] new_slab+0xa6/0x6c0 mm/slub.c:3525 refill_objects+0x277/0x420 mm/slub.c:7272 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4652 alloc_from_pcs mm/slub.c:4750 [inline] slab_alloc_node mm/slub.c:4884 [inline] __kmalloc_cache_noprof+0x493/0x6f0 mm/slub.c:5415 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] call_usermodehelper_setup+0xaf/0x360 kernel/umh.c:362 kobject_uevent_env+0x17c1/0x18b0 lib/kobject_uevent.c:631 kernel_add_sysfs_param kernel/params.c:801 [inline] param_sysfs_builtin kernel/params.c:836 [inline] param_sysfs_builtin_init+0x37b/0x3f0 kernel/params.c:972 do_one_initcall+0x121/0x750 init/main.c:1392 do_initcall_level init/main.c:1454 [inline] do_initcalls init/main.c:1470 [inline] do_basic_setup init/main.c:1490 [inline] kernel_init_freeable+0x6ea/0x7b0 init/main.c:1703 kernel_init+0x1f/0x1e0 init/main.c:1593 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 page_owner free stack trace missing Memory state around the buggy address: ffff8880339c0680: 00 00 00 04 fc fc fc fc fc fc fc fc fc fc fc fc ffff8880339c0700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880339c0780: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ^ ffff8880339c0800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880339c0880: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================