================================================================== 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 ffff888051b73290 by task syz-executor.0/16815 CPU: 1 PID: 16815 Comm: syz-executor.0 Not tainted 4.19.117-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+0x188/0x20d lib/dump_stack.c:118 print_address_description.cold+0x7c/0x212 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:4431 [inline] con_font_op+0x1f7/0x1130 drivers/tty/vt/vt.c:4590 vt_ioctl+0x16f1/0x2500 drivers/tty/vt/vt_ioctl.c:980 tty_ioctl+0x7a1/0x1420 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: 0033:0x45c829 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:00007fab29e29c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e6600 RCX: 000000000045c829 RDX: 00000000200008c0 RSI: 0000000000004b72 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000036d R14: 00000000004c5ddf R15: 00007fab29e2a6d4 Allocated by task 15416: set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531 __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15b/0x770 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:4523 [inline] con_font_op+0xd3e/0x1130 drivers/tty/vt/vt.c:4588 vt_ioctl+0xcd0/0x2500 drivers/tty/vt/vt_ioctl.c:928 tty_ioctl+0x7a1/0x1420 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 14426: set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/kasan.c:521 __cache_free mm/slab.c:3503 [inline] kfree+0xce/0x220 mm/slab.c:3822 kvfree+0x59/0x60 mm/util.c:452 __free_fdtable+0x2d/0x70 fs/file.c:31 put_files_struct fs/file.c:420 [inline] put_files_struct+0x248/0x2e0 fs/file.c:413 exit_files+0x7e/0xa0 fs/file.c:445 do_exit+0xb94/0x2f30 kernel/exit.c:875 do_group_exit+0x125/0x350 kernel/exit.c:983 __do_sys_exit_group kernel/exit.c:994 [inline] __se_sys_exit_group kernel/exit.c:992 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:992 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888051b72e80 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 1040 bytes inside of 2048-byte region [ffff888051b72e80, ffff888051b73680) The buggy address belongs to the page: page:ffffea000146dc80 count:1 mapcount:0 mapping:ffff88812c39cc40 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea00013b5008 ffffea00025c0108 ffff88812c39cc40 raw: 0000000000000000 ffff888051b72600 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888051b73180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888051b73200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888051b73280: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888051b73300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888051b73380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================