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BUG: KMSAN: kernel-infoleak in copy_to_user include/linux/uaccess.h:184 [inline]
BUG: KMSAN: kernel-infoleak in vcs_read+0x18ba/0x1cc0 drivers/tty/vt/vc_screen.c:352
CPU: 1 PID: 8300 Comm: syz-executor6 Not tainted 4.17.0+ #8
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+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1122
 kmsan_internal_check_memory+0x138/0x1f0 mm/kmsan/kmsan.c:1216
 kmsan_copy_to_user+0x7a/0x160 mm/kmsan/kmsan.c:1258
 copy_to_user include/linux/uaccess.h:184 [inline]
 vcs_read+0x18ba/0x1cc0 drivers/tty/vt/vc_screen.c:352
 do_loop_readv_writev fs/read_write.c:700 [inline]
 do_iter_read+0x884/0xd80 fs/read_write.c:924
 vfs_readv fs/read_write.c:986 [inline]
 do_readv+0x295/0x5f0 fs/read_write.c:1019
 __do_sys_readv fs/read_write.c:1106 [inline]
 __se_sys_readv fs/read_write.c:1103 [inline]
 __x64_sys_readv+0xe1/0x120 fs/read_write.c:1103
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x455b29
RSP: 002b:00007f7f988e9c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000013
RAX: ffffffffffffffda RBX: 00007f7f988ea6d4 RCX: 0000000000455b29
RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c06ab R14: 00000000004cfef8 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:294 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:686
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:464
 vcs_read+0xd01/0x1cc0 drivers/tty/vt/vc_screen.c:274
 do_loop_readv_writev fs/read_write.c:700 [inline]
 do_iter_read+0x884/0xd80 fs/read_write.c:924
 vfs_readv fs/read_write.c:986 [inline]
 do_readv+0x295/0x5f0 fs/read_write.c:1019
 __do_sys_readv fs/read_write.c:1106 [inline]
 __se_sys_readv fs/read_write.c:1103 [inline]
 __x64_sys_readv+0xe1/0x120 fs/read_write.c:1103
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:189
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:315
 __kmalloc+0x13a/0x350 mm/slub.c:3818
 kmalloc include/linux/slab.h:517 [inline]
 vc_allocate+0x438/0x800 drivers/tty/vt/vt.c:787
 con_install+0x8c/0x640 drivers/tty/vt/vt.c:2880
 tty_driver_install_tty drivers/tty/tty_io.c:1224 [inline]
 tty_init_dev+0x1b5/0x1020 drivers/tty/tty_io.c:1324
 tty_open_by_driver drivers/tty/tty_io.c:1959 [inline]
 tty_open+0x17b4/0x2ed0 drivers/tty/tty_io.c:2007
 chrdev_open+0xc25/0xd90 fs/char_dev.c:417
 do_dentry_open+0xccc/0x1440 fs/open.c:794
 vfs_open+0x1b6/0x2f0 fs/open.c:908
 do_last fs/namei.c:3365 [inline]
 path_openat+0x4771/0x6640 fs/namei.c:3506
 do_filp_open+0x261/0x640 fs/namei.c:3540
 do_sys_open+0x624/0x960 fs/open.c:1101
 __do_sys_open fs/open.c:1119 [inline]
 __se_sys_open fs/open.c:1114 [inline]
 __x64_sys_open+0xf2/0x130 fs/open.c:1114
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Bytes 0-79 of 240 are uninitialized
Memory access starts at ffff88010c2e4000
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