================================================================== 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 6 at addr ffff88808cfeb6ce by task syz-executor.3/16943 CPU: 1 PID: 16943 Comm: syz-executor.3 Not tainted 4.19.126-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+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 RIP: 0033:0x45ca69 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:00007f128ed57c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e97c0 RCX: 000000000045ca69 RDX: 00000000200000c0 RSI: 0000000000004b60 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000425 R14: 00000000004c6e9d R15: 00007f128ed586d4 Allocated by task 15240: __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 13977: __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+0xb91/0x2f00 kernel/exit.c:875 do_group_exit+0x125/0x310 kernel/exit.c:983 get_signal+0x3f5/0x1f30 kernel/signal.c:2588 do_signal+0x8f/0x1620 arch/x86/kernel/signal.c:821 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 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 ffff88808cfeb1c0 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 1294 bytes inside of 2048-byte region [ffff88808cfeb1c0, ffff88808cfeb9c0) The buggy address belongs to the page: page:ffffea000233fa80 count:1 mapcount:0 mapping:ffff88812c3dcc40 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea000290d908 ffffea0001320888 ffff88812c3dcc40 raw: 0000000000000000 ffff88808cfea0c0 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808cfeb580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88808cfeb600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88808cfeb680: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ^ ffff88808cfeb700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88808cfeb780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================