================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:348 [inline] BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x28d/0x5b0 drivers/video/fbdev/core/fbcon.c:2446 Read of size 16 at addr ffff88808be7d990 by task syz-executor.2/32086 CPU: 0 PID: 32086 Comm: syz-executor.2 Not tainted 4.19.128-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+0x1fc/0x2fe lib/dump_stack.c:118 print_address_description.cold+0x54/0x222 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+0x88/0x2b9 mm/kasan/report.c:396 memcpy+0x20/0x50 mm/kasan/kasan.c:302 memcpy include/linux/string.h:348 [inline] fbcon_get_font+0x28d/0x5b0 drivers/video/fbdev/core/fbcon.c:2446 con_font_get drivers/tty/vt/vt.c:4437 [inline] con_font_op+0x1f7/0x1130 drivers/tty/vt/vt.c:4596 vt_ioctl+0x16f1/0x2500 drivers/tty/vt/vt_ioctl.c:980 tty_ioctl+0x7a5/0x1420 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ca59 Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f643af5dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e70a0 RCX: 000000000045ca59 RDX: 0000000020000000 RSI: 0000000000004b72 RDI: 0000000000000004 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000379 R14: 00000000004c60df R15: 00007f643af5e6d4 Allocated by task 24048: __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15a/0x3c0 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] fbcon_set_font+0x331/0x870 drivers/video/fbdev/core/fbcon.c:2644 con_font_set drivers/tty/vt/vt.c:4529 [inline] con_font_op+0xd3e/0x1130 drivers/tty/vt/vt.c:4594 vt_ioctl+0xcd0/0x2500 drivers/tty/vt/vt_ioctl.c:928 tty_ioctl+0x7a5/0x1420 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 23166: __cache_free mm/slab.c:3503 [inline] kfree+0xce/0x220 mm/slab.c:3822 kvfree+0x59/0x60 mm/util.c:452 seq_release+0x4f/0x80 fs/seq_file.c:359 kernfs_fop_release+0xf2/0x190 fs/kernfs/file.c:781 __fput+0x2cd/0x890 fs/file_table.c:278 task_work_run+0x13f/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88808be7cc80 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 3344 bytes inside of 4096-byte region [ffff88808be7cc80, ffff88808be7dc80) The buggy address belongs to the page: page:ffffea00022f9f00 count:1 mapcount:0 mapping:ffff88812c3dcdc0 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea00013d0388 ffffea00014cfc88 ffff88812c3dcdc0 raw: 0000000000000000 ffff88808be7cc80 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808be7d880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88808be7d900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88808be7d980: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88808be7da00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88808be7da80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================