From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932075AbeEOQ0E (ORCPT ); Tue, 15 May 2018 12:26:04 -0400 Received: from mail-it0-f71.google.com ([209.85.214.71]:50262 "EHLO mail-it0-f71.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752453AbeEOQ0C (ORCPT ); Tue, 15 May 2018 12:26:02 -0400 X-Google-Smtp-Source: AB8JxZqvxYt6hgkHpo3ylw7NuKuk6ZV7Po6m+qznNsRk2my7ugMXwra6AvbvG+W6H5Oe0tAjy4TTvnt+l+kFi1h5O9liI58GyqPC MIME-Version: 1.0 Date: Tue, 15 May 2018 09:26:01 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000da269e056c410efd@google.com> Subject: KMSAN: uninit-value in vcs_read From: syzbot To: gregkh@linuxfoundation.org, jslaby@suse.com, kstewart@linuxfoundation.org, linux-kernel@vger.kernel.org, pombredanne@nexb.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, viro@zeniv.linux.org.uk Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: e2ab7e8abba4 kmsan: temporarily disable visitAsmInstructio.. git tree: https://github.com/google/kmsan.git/master console output: https://syzkaller.appspot.com/x/log.txt?x=158135db800000 kernel config: https://syzkaller.appspot.com/x/.config?x=5bf8b7964e37a698 dashboard link: https://syzkaller.appspot.com/bug?extid=fed4435f163beccc67eb compiler: clang version 7.0.0 (trunk 329391) syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=17a2f91b800000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17bd452b800000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+fed4435f163beccc67eb@syzkaller.appspotmail.com ================================================================== BUG: KMSAN: uninit-value in copy_to_user include/linux/uaccess.h:184 [inline] BUG: KMSAN: uninit-value in vcs_read+0x18ba/0x1cc0 drivers/tty/vt/vc_screen.c:352 CPU: 1 PID: 3501 Comm: syzkaller315412 Not tainted 4.16.0+ #82 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 kmsan_internal_check_memory+0x125/0x1d0 mm/kmsan/kmsan.c:1157 kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199 copy_to_user include/linux/uaccess.h:184 [inline] vcs_read+0x18ba/0x1cc0 drivers/tty/vt/vc_screen.c:352 __vfs_read+0x19f/0x8e0 fs/read_write.c:411 vfs_read+0x36c/0x6c0 fs/read_write.c:447 SYSC_pread64+0x275/0x310 fs/read_write.c:611 SyS_pread64+0x65/0x90 fs/read_write.c:598 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x443d39 RSP: 002b:00007ffcbd3c35f8 EFLAGS: 00000213 ORIG_RAX: 0000000000000011 RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443d39 RDX: 0000000000000083 RSI: 0000000020000140 RDI: 0000000000000003 RBP: 00000000006ce018 R08: 00000000004002e0 R09: 00000000004002e0 R10: 0000000000000000 R11: 0000000000000213 R12: 00000000004019e0 R13: 0000000000401a70 R14: 0000000000000000 R15: 0000000000000000 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_save_stack mm/kmsan/kmsan.c:293 [inline] kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521 vcs_read+0xd01/0x1cc0 drivers/tty/vt/vc_screen.c:274 __vfs_read+0x19f/0x8e0 fs/read_write.c:411 vfs_read+0x36c/0x6c0 fs/read_write.c:447 SYSC_pread64+0x275/0x310 fs/read_write.c:611 SyS_pread64+0x65/0x90 fs/read_write.c:598 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314 __kmalloc+0x23c/0x350 mm/slub.c:3791 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:2876 tty_driver_install_tty drivers/tty/tty_io.c:1224 [inline] tty_init_dev+0x1b0/0x1020 drivers/tty/tty_io.c:1324 tty_open_by_driver drivers/tty/tty_io.c:1959 [inline] tty_open+0x15e9/0x2ea0 drivers/tty/tty_io.c:2007 chrdev_open+0xc20/0xd90 fs/char_dev.c:417 do_dentry_open+0xcc6/0x1430 fs/open.c:752 vfs_open+0x1b7/0x2e0 fs/open.c:866 do_last fs/namei.c:3379 [inline] path_openat+0x460a/0x6520 fs/namei.c:3520 do_filp_open+0x261/0x640 fs/namei.c:3554 do_sys_open+0x624/0x960 fs/open.c:1059 SYSC_open+0xab/0xc0 fs/open.c:1077 SyS_open+0x54/0x80 fs/open.c:1072 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Bytes 0-79 of 131 are uninitialized ================================================================== --- This bug is generated by a bot. 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