================================================================== BUG: KASAN: slab-out-of-bounds in soft_cursor+0x458/0xa10 drivers/video/fbdev/core/softcursor.c:70 Read of size 45 at addr ffff888058282da0 by task syz.6.1849/13321 CPU: 0 UID: 0 PID: 13321 Comm: syz.6.1849 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 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/0x1c0 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 soft_cursor+0x458/0xa10 drivers/video/fbdev/core/softcursor.c:70 ccw_cursor+0xd7f/0x15b0 drivers/video/fbdev/core/fbcon_ccw.c:341 fbcon_cursor+0x43c/0x5e0 drivers/video/fbdev/core/fbcon.c:1427 hide_cursor+0x87/0x230 drivers/tty/vt/vt.c:883 redraw_screen+0x5d4/0x760 drivers/tty/vt/vt.c:985 vc_do_resize+0xc3d/0xeb0 drivers/tty/vt/vt.c:1309 vc_resize include/linux/vt_kern.h:49 [inline] fbcon_do_set_font+0x443/0x8c0 drivers/video/fbdev/core/fbcon.c:2435 fbcon_set_font+0x4be/0x730 drivers/video/fbdev/core/fbcon.c:2518 con_font_set drivers/tty/vt/vt.c:4992 [inline] con_font_op+0x9c0/0x1040 drivers/tty/vt/vt.c:5032 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline] vt_ioctl+0xe00/0x3150 drivers/tty/vt/vt_ioctl.c:745 tty_ioctl+0x26a/0x1640 drivers/tty/tty_io.c:2792 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2d2979e0d9 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:00007f2d279f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f2d29a25fa0 RCX: 00007f2d2979e0d9 RDX: 00002000000001c0 RSI: 0000000000004b72 RDI: 0000000000000003 RBP: 00007f2d29835024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2d29a26038 R14: 00007f2d29a25fa0 R15: 00007ffe61140388 Allocated by task 12713: 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:5334 [inline] __kmalloc_noprof+0x322/0x820 mm/slub.c:5359 _kmalloc_noprof include/linux/slab.h:992 [inline] _kmalloc_array_noprof include/linux/slab.h:1208 [inline] font_data_rotate+0x353/0x3b0 lib/fonts/font_rotate.c:231 fbcon_rotate_font+0x2bf/0x510 drivers/video/fbdev/core/fbcon_rotate.c:33 fbcon_modechanged+0x218/0x7f0 drivers/video/fbdev/core/fbcon.c:2664 fbcon_set_all_vcs+0x39b/0x470 drivers/video/fbdev/core/fbcon.c:2725 fbcon_rotate_all drivers/video/fbdev/core/fbcon.c:254 [inline] rotate_all_store+0x31e/0x410 drivers/video/fbdev/core/fbcon.c:3218 dev_attr_store+0x58/0x80 drivers/base/core.c:2505 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888058282800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 416 bytes to the right of allocated 1024-byte region [ffff888058282800, ffff888058282c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888058286000 pfn:0x58280 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801c042dc0 ffffea0000d96c10 ffffea0000d50e10 raw: ffff888058286000 000000080010000b 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801c042dc0 ffffea0000d96c10 ffffea0000d50e10 head: ffff888058286000 000000080010000b 00000000f5000000 0000000000000000 head: 00fff00000000003 fffffffffffffe01 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 41, tgid 41 (kworker/1:1), ts 49390293375, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3266 [inline] allocate_slab mm/slub.c:3380 [inline] new_slab+0xa2/0x640 mm/slub.c:3426 refill_objects+0xe3/0x410 mm/slub.c:7310 refill_sheaf mm/slub.c:2804 [inline] __pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675 alloc_from_pcs mm/slub.c:4773 [inline] slab_alloc_node mm/slub.c:4905 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kmalloc_noprof+0x66d/0x820 mm/slub.c:5359 _kmalloc_noprof include/linux/slab.h:992 [inline] _kzalloc_noprof include/linux/slab.h:1309 [inline] neigh_alloc net/core/neighbour.c:518 [inline] ___neigh_create+0x1532/0x2940 net/core/neighbour.c:652 ip6_finish_output2+0xffa/0x1ce0 net/ipv6/ip6_output.c:128 __ip6_finish_output+0x357/0xdf0 net/ipv6/ip6_output.c:208 ip6_finish_output net/ipv6/ip6_output.c:219 [inline] NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x2aa/0xa60 net/ipv6/ip6_output.c:246 dst_output include/net/dst.h:470 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK.constprop.0+0x115/0x5a0 include/linux/netfilter.h:312 mld_sendpack+0x8f7/0xec0 net/ipv6/mcast.c:1869 mld_send_cr net/ipv6/mcast.c:2170 [inline] mld_ifc_work+0x75a/0xc10 net/ipv6/mcast.c:2710 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 page_owner free stack trace missing Memory state around the buggy address: ffff888058282c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888058282d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888058282d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888058282e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888058282e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================