================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:348 [inline] BUG: KASAN: slab-out-of-bounds in soft_cursor+0x439/0xa30 drivers/video/fbdev/core/softcursor.c:70 Read of size 8 at addr ffff888091d36890 by task kworker/0:3/7976 CPU: 0 PID: 7976 Comm: kworker/0:3 Not tainted 4.19.93-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_power_efficient fb_flashcursor 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] soft_cursor+0x439/0xa30 drivers/video/fbdev/core/softcursor.c:70 bit_cursor+0x12fc/0x1a60 drivers/video/fbdev/core/bitblit.c:386 fb_flashcursor+0x3a6/0x450 drivers/video/fbdev/core/fbcon.c:399 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Allocated by task 9994: 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 4970: 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 load_elf_binary+0x249e/0x53a0 fs/binfmt_elf.c:1117 search_binary_handler fs/exec.c:1653 [inline] search_binary_handler+0x179/0x570 fs/exec.c:1631 exec_binprm fs/exec.c:1695 [inline] __do_execve_file.isra.0+0x1227/0x2150 fs/exec.c:1819 do_execveat_common fs/exec.c:1866 [inline] do_execve fs/exec.c:1883 [inline] __do_sys_execve fs/exec.c:1964 [inline] __se_sys_execve fs/exec.c:1959 [inline] __x64_sys_execve+0x8f/0xc0 fs/exec.c:1959 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 ffff888091d36780 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 272 bytes inside of 512-byte region [ffff888091d36780, ffff888091d36980) The buggy address belongs to the page: page:ffffea0002474d80 count:1 mapcount:0 mapping:ffff88812c31c940 index:0x0 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffffea000264b708 ffffea00014f9708 ffff88812c31c940 raw: 0000000000000000 ffff888091d36000 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888091d36780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888091d36800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888091d36880: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888091d36900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888091d36980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================