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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:348 [inline]
BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x2b2/0x5e0 drivers/video/fbdev/core/fbcon.c:2443
Read of size 4 at addr ffff88808f0a7e50 by task syz-executor.0/8249

CPU: 0 PID: 8249 Comm: syz-executor.0 Not tainted 4.19.90-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+0x197/0x210 lib/dump_stack.c:118
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x123/0x190 mm/kasan/kasan.c:267
 memcpy+0x24/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:348 [inline]
 fbcon_get_font+0x2b2/0x5e0 drivers/video/fbdev/core/fbcon.c:2443
 con_font_get drivers/tty/vt/vt.c:4400 [inline]
 con_font_op+0x20b/0x1250 drivers/tty/vt/vt.c:4559
 do_fontx_ioctl drivers/tty/vt/vt_ioctl.c:252 [inline]
 vt_ioctl+0x1c93/0x2530 drivers/tty/vt/vt_ioctl.c:930
 tty_ioctl+0x7f3/0x1510 drivers/tty/tty_io.c:2669
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a919
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f37bb4c8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a919
RDX: 0000000020000440 RSI: 0000000000004b6b RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f37bb4c96d4
R13: 00000000004c3561 R14: 00000000004d89e8 R15: 00000000ffffffff

Allocated by task 31282:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531
 __do_kmalloc mm/slab.c:3727 [inline]
 __kmalloc+0x15d/0x750 mm/slab.c:3736
 kmalloc include/linux/slab.h:520 [inline]
 fbcon_set_font+0x32d/0x860 drivers/video/fbdev/core/fbcon.c:2641
 con_font_set drivers/tty/vt/vt.c:4492 [inline]
 con_font_op+0xe18/0x1250 drivers/tty/vt/vt.c:4557
 vt_ioctl+0xd2e/0x2530 drivers/tty/vt/vt_ioctl.c:913
 tty_ioctl+0x7f3/0x1510 drivers/tty/tty_io.c:2669
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 7645:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcf/0x220 mm/slab.c:3822
 syslog_print kernel/printk/printk.c:1360 [inline]
 do_syslog kernel/printk/printk.c:1477 [inline]
 do_syslog+0xcf2/0x1690 kernel/printk/printk.c:1451
 kmsg_read+0x8f/0xc0 fs/proc/kmsg.c:40
 proc_reg_read+0x1f8/0x2b0 fs/proc/inode.c:231
 __vfs_read+0x114/0x800 fs/read_write.c:416
 vfs_read+0x194/0x3d0 fs/read_write.c:452
 ksys_read+0x14f/0x2d0 fs/read_write.c:579
 __do_sys_read fs/read_write.c:589 [inline]
 __se_sys_read fs/read_write.c:587 [inline]
 __x64_sys_read+0x73/0xb0 fs/read_write.c:587
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88808f0a7b40
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 784 bytes inside of
 1024-byte region [ffff88808f0a7b40, ffff88808f0a7f40)
The buggy address belongs to the page:
page:ffffea00023c2980 count:1 mapcount:0 mapping:ffff88812c31cac0 index:0xffff88808f0a6040 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffffea00028e6788 ffffea00022c8988 ffff88812c31cac0
raw: ffff88808f0a6040 ffff88808f0a6040 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808f0a7d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88808f0a7d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88808f0a7e00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
                                                 ^
 ffff88808f0a7e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808f0a7f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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