================================================================== BUG: KASAN: null-ptr-deref in memmove include/linux/string.h:395 [inline] BUG: KASAN: null-ptr-deref in scr_memmovew include/linux/vt_buffer.h:68 [inline] BUG: KASAN: null-ptr-deref in insert_char+0x206/0x400 drivers/tty/vt/vt.c:839 Read of size 56 at addr 0000000000000012 by task syz-executor.2/859 CPU: 0 PID: 859 Comm: syz-executor.2 Not tainted 5.5.0-rc6-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 __kasan_report.cold+0x5/0x41 mm/kasan/report.c:510 kasan_report+0x12/0x20 mm/kasan/common.c:639 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192 memmove+0x24/0x50 mm/kasan/common.c:116 memmove include/linux/string.h:395 [inline] scr_memmovew include/linux/vt_buffer.h:68 [inline] insert_char+0x206/0x400 drivers/tty/vt/vt.c:839 csi_at drivers/tty/vt/vt.c:1964 [inline] do_con_trol+0x41a6/0x61b0 drivers/tty/vt/vt.c:2431 do_con_write.part.0+0xfd9/0x1ef0 drivers/tty/vt/vt.c:2797 do_con_write drivers/tty/vt/vt.c:2565 [inline] con_write+0x46/0xd0 drivers/tty/vt/vt.c:3135 process_output_block drivers/tty/n_tty.c:595 [inline] n_tty_write+0x40e/0x1080 drivers/tty/n_tty.c:2333 do_tty_write drivers/tty/tty_io.c:962 [inline] tty_write+0x496/0x7f0 drivers/tty/tty_io.c:1046 __vfs_write+0x8a/0x110 fs/read_write.c:494 vfs_write+0x268/0x5d0 fs/read_write.c:558 ksys_write+0x14f/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45af49 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:00007fe314a38c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49 RDX: 0000000000000078 RSI: 0000000020000000 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe314a396d4 R13: 00000000004cd013 R14: 00000000004e8760 R15: 00000000ffffffff ==================================================================