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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:406 [inline]
BUG: KASAN: slab-out-of-bounds in soft_cursor+0x44b/0xa30 drivers/video/fbdev/core/softcursor.c:70
Read of size 8 at addr ffff88809f7b9510 by task syz-executor.5/23765

CPU: 0 PID: 23765 Comm: syz-executor.5 Not tainted 5.8.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 check_memory_region_inline mm/kasan/generic.c:186 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
 memcpy+0x20/0x60 mm/kasan/common.c:105
 memcpy include/linux/string.h:406 [inline]
 soft_cursor+0x44b/0xa30 drivers/video/fbdev/core/softcursor.c:70
 bit_cursor+0x1166/0x17d0 drivers/video/fbdev/core/bitblit.c:386
 fbcon_cursor+0x52b/0x650 drivers/video/fbdev/core/fbcon.c:1411
 hide_cursor+0x85/0x280 drivers/tty/vt/vt.c:902
 redraw_screen+0x5e1/0x770 drivers/tty/vt/vt.c:1006
 vc_do_resize+0x110e/0x13f0 drivers/tty/vt/vt.c:1314
 vt_ioctl+0x2037/0x2670 drivers/tty/vt/vt_ioctl.c:901
 tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656
 vfs_ioctl fs/ioctl.c:48 [inline]
 ksys_ioctl+0x11a/0x180 fs/ioctl.c:753
 __do_sys_ioctl fs/ioctl.c:762 [inline]
 __se_sys_ioctl fs/ioctl.c:760 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cba9
Code: Bad RIP value.
RSP: 002b:00007ff4af46ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004f3d80 RCX: 000000000045cba9
RDX: 0000000020000000 RSI: 000000000000560a RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000682 R14: 00000000004c9910 R15: 00007ff4af46f6d4

Allocated by task 17640:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x17a/0x340 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 fbcon_set_font+0x34f/0x8b0 drivers/video/fbdev/core/fbcon.c:2673
 con_font_set drivers/tty/vt/vt.c:4571 [inline]
 con_font_op+0xd25/0x1110 drivers/tty/vt/vt.c:4636
 vt_ioctl+0x1180/0x2670 drivers/tty/vt/vt_ioctl.c:928
 tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656
 vfs_ioctl fs/ioctl.c:48 [inline]
 ksys_ioctl+0x11a/0x180 fs/ioctl.c:753
 __do_sys_ioctl fs/ioctl.c:762 [inline]
 __se_sys_ioctl fs/ioctl.c:760 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 16860:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 kasan_set_free_info mm/kasan/common.c:316 [inline]
 __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x103/0x2c0 mm/slab.c:3757
 skb_free_head net/core/skbuff.c:590 [inline]
 skb_release_data+0x6d9/0x910 net/core/skbuff.c:610
 skb_release_all net/core/skbuff.c:664 [inline]
 __kfree_skb net/core/skbuff.c:678 [inline]
 kfree_skb.part.0+0xc2/0x350 net/core/skbuff.c:696
 kfree_skb+0x7d/0x100 include/linux/refcount.h:270
 ip_rcv_finish_core.constprop.0+0xb84/0x1e60 net/ipv4/ip_input.c:405
 ip_rcv_finish+0x144/0x2f0 net/ipv4/ip_input.c:426
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip_rcv+0xaa/0xd0 net/ipv4/ip_input.c:539
 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5281
 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5395
 process_backlog+0x28d/0x7f0 net/core/dev.c:6239
 napi_poll net/core/dev.c:6684 [inline]
 net_rx_action+0x4a1/0xe60 net/core/dev.c:6752
 __do_softirq+0x34c/0xa60 kernel/softirq.c:292

The buggy address belongs to the object at ffff88809f7b9400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 272 bytes inside of
 512-byte region [ffff88809f7b9400, ffff88809f7b9600)
The buggy address belongs to the page:
page:ffffea00027dee40 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88809f7b9000
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00029b9148 ffffea00028b1088 ffff8880aa000a80
raw: ffff88809f7b9000 ffff88809f7b9000 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809f7b9400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88809f7b9480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88809f7b9500: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff88809f7b9580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809f7b9600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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