=====================================================
BUG: KMSAN: uninit-value in do_update_region+0x6ef/0xb80 drivers/tty/vt/vt.c:665
CPU: 1 PID: 8986 Comm: syz-executor.4 Not tainted 5.6.0-rc2-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+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 do_update_region+0x6ef/0xb80 drivers/tty/vt/vt.c:665
 csi_J+0xe5c/0x1060 drivers/tty/vt/vt.c:1531
 do_con_trol drivers/tty/vt/vt.c:2367 [inline]
 do_con_write+0x8cbf/0x13160 drivers/tty/vt/vt.c:2797
 con_write+0x8e/0xe0 drivers/tty/vt/vt.c:3135
 process_output_block drivers/tty/n_tty.c:595 [inline]
 n_tty_write+0x13c7/0x1d40 drivers/tty/n_tty.c:2333
 do_tty_write drivers/tty/tty_io.c:962 [inline]
 tty_write+0xc06/0x12e0 drivers/tty/tty_io.c:1046
 do_loop_readv_writev fs/read_write.c:717 [inline]
 do_iter_write+0x812/0xdc0 fs/read_write.c:1000
 compat_writev+0x2df/0x5a0 fs/read_write.c:1351
 do_compat_writev fs/read_write.c:1372 [inline]
 __do_compat_sys_writev fs/read_write.c:1383 [inline]
 __se_compat_sys_writev fs/read_write.c:1379 [inline]
 __ia32_compat_sys_writev+0x1d2/0x3f0 fs/read_write.c:1379
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f4bd99
Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5d460cc EFLAGS: 00000296 ORIG_RAX: 0000000000000092
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000200005c0
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

------------[ cut here ]------------
slab index 1824 out of bounds (708) for stack id 07200720
WARNING: CPU: 1 PID: 8986 at lib/stackdepot.c:230 stack_depot_fetch+0x29/0x70 lib/stackdepot.c:229