ip (2755) used greatest stack depth: 24376 bytes left
audit: type=1400 audit(1542178622.559:5): avc:  denied  { associate } for  pid=2069 comm="syz-executor2" name="syz2" scontext=unconfined_u:object_r:unlabeled_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=filesystem permissive=1
==================================================================
BUG: KASAN: user-memory-access in bitmap_zero include/linux/bitmap.h:197 [inline]
BUG: KASAN: user-memory-access in n_tty_set_termios+0xf6/0xd30 drivers/tty/n_tty.c:1786
Write of size 512 at addr 0000000000001060 by task syz-executor3/4753

CPU: 1 PID: 4753 Comm: syz-executor3 Not tainted 4.9.135+ #65
 ffff8801d993f708 ffffffff81b42b89 0000000000001060 0000000000000200
 0000000000000001 000000000000005d ffff8801d993f848 ffff8801d993f750
 ffffffff81500be2 ffffffff81d2f416 0000000000000286 31f22736ef2afe96
Call Trace:
 [<ffffffff81b42b89>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b42b89>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81500be2>] kasan_report_error mm/kasan/report.c:353 [inline]
 [<ffffffff81500be2>] kasan_report.cold.6+0x6d/0x2fe mm/kasan/report.c:412
 [<ffffffff814f1d4d>] check_memory_region_inline mm/kasan/kasan.c:318 [inline]
 [<ffffffff814f1d4d>] check_memory_region+0x14d/0x1b0 mm/kasan/kasan.c:325
 [<ffffffff814f2303>] memset+0x23/0x40 mm/kasan/kasan.c:343
 [<ffffffff81d2f416>] bitmap_zero include/linux/bitmap.h:197 [inline]
 [<ffffffff81d2f416>] n_tty_set_termios+0xf6/0xd30 drivers/tty/n_tty.c:1786
 [<ffffffff81d3a206>] tty_set_termios+0x626/0x8a0 drivers/tty/tty_ioctl.c:562
 [<ffffffff81d3b1ef>] set_termios+0x38f/0x620 drivers/tty/tty_ioctl.c:635
 [<ffffffff81d3bdc2>] tty_mode_ioctl+0x8c2/0x980 drivers/tty/tty_ioctl.c:970
 [<ffffffff81d3bf24>] n_tty_ioctl_helper+0x44/0x370 drivers/tty/tty_ioctl.c:1161
 [<ffffffff81d36916>] n_tty_ioctl+0x46/0x2e0 drivers/tty/n_tty.c:2452
 [<ffffffff81d28310>] tty_ioctl+0x440/0x2190 drivers/tty/tty_io.c:3014
 [<ffffffff81546ddc>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff81546ddc>] file_ioctl fs/ioctl.c:493 [inline]
 [<ffffffff81546ddc>] do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677
 [<ffffffff81547e5f>] SYSC_ioctl fs/ioctl.c:694 [inline]
 [<ffffffff81547e5f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82816b93>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
==================================================================