From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.7 required=3.0 tests=BAYES_00,FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58C60C43466 for ; Sun, 20 Sep 2020 09:22:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 232ED2075E for ; Sun, 20 Sep 2020 09:22:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726301AbgITJWR (ORCPT ); Sun, 20 Sep 2020 05:22:17 -0400 Received: from mail-il1-f206.google.com ([209.85.166.206]:53408 "EHLO mail-il1-f206.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726247AbgITJWQ (ORCPT ); Sun, 20 Sep 2020 05:22:16 -0400 Received: by mail-il1-f206.google.com with SMTP id w12so2037518ilc.20 for ; Sun, 20 Sep 2020 02:22:15 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=IJjZQysLXu1/RF9ewteRS4rH+LUmVeCkOSAwIBABgto=; b=BVAvbMynTnySMh7jOvAuTOwUW3NymmAtFHDrG7m/sUlKE5aKvzNFbTJ9OlUhEqNDvD xApxt3YObXuUbQxQ5brWVETmUy+lxwoUQEvIyhGD7vZW1tDGqpB/4xpIhIw/bSOiiZuN bC1KQiUhMU3ooXHVD4fhqfLIvx4N2zlC7vBQ14ODnypHBxXIpfVq1Nwgh08NijSYVFJx Qq8m/rs4XE03xIiwNUTF7X3T5uU2pUf2SapRDbygroNwsAfIJVVOer0LmEkwh6ud8WnV rTn5hP+9iNSbdwHcJHsZFXNiA4gVeblr+KnLUSA61hzyU1XIR3jkceo+f02ryEc01c07 yPFQ== X-Gm-Message-State: AOAM533+2PeXr98uglrTlgVOivkCmKy6t2TthqjgpC6ay59rHdkGBX3D bzusNU4Yiap8YF/GEgp52uyq2p/pyhiXxt5x7ojq5aLmStLr X-Google-Smtp-Source: ABdhPJzegCGBiRCxz2F/3M3r3CJ9P0i4yQ+5vnz9X+cIpF7YYwXUhsCfH9xUomiztgWcfMIp0sV3NsHTm31QB5oFGN1R31LvVSc+ MIME-Version: 1.0 X-Received: by 2002:a5e:8e0a:: with SMTP id a10mr33673966ion.200.1600593735382; Sun, 20 Sep 2020 02:22:15 -0700 (PDT) Date: Sun, 20 Sep 2020 02:22:15 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000006fb0905afbb458d@google.com> Subject: KMSAN: uninit-value in is_idle_task From: syzbot To: bp@alien8.de, glider@google.com, hpa@zytor.com, linux-kernel@vger.kernel.org, luto@kernel.org, mingo@redhat.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, x86@kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following issue on: HEAD commit: 3b3ea602 x86: add failure injection to get/put/clear_user git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=144b8965900000 kernel config: https://syzkaller.appspot.com/x/.config?x=ee5f7a0b2e48ed66 dashboard link: https://syzkaller.appspot.com/bug?extid=a4b29e75da1c2c8bd34f compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+a4b29e75da1c2c8bd34f@syzkaller.appspotmail.com ===================================================== BUG: KMSAN: uninit-value in is_idle_task+0x65/0x70 include/linux/sched.h:1672 CPU: 0 PID: 5351 Comm: syz-executor.3 Not tainted 5.8.0-rc5-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+0x21c/0x280 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 is_idle_task+0x65/0x70 include/linux/sched.h:1672 sysvec_apic_timer_interrupt+0x2e/0x130 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:593 RIP: 0010:kmsan_get_metadata+0x136/0x180 mm/kmsan/kmsan_shadow.c:201 Code: 75 5f 48 89 df e8 6a 00 00 00 48 85 c0 74 50 48 8b 48 40 48 85 c9 74 47 48 8b 40 48 48 85 c0 74 3e 81 e3 ff 0f 00 00 45 84 f6 <48> 0f 45 c8 48 b8 00 00 00 00 00 16 00 00 48 01 c8 48 c1 e8 04 48 RSP: 0018:ffff8881cde9f460 EFLAGS: 00000246 RAX: ffffea00090451b0 RBX: 0000000000000608 RCX: ffffea00090311b0 RDX: 00000001cde9f608 RSI: 0000000000000720 RDI: ffff8881cde9f608 RBP: ffff8881cde9f478 R08: ffffea000000000f R09: ffff88812fffa000 R10: 0000000000000004 R11: 00000000ffffffff R12: 000000000000006a R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 kmsan_get_shadow_origin_ptr+0x6c/0xb0 mm/kmsan/kmsan_shadow.c:149 __msan_metadata_ptr_for_load_4+0x10/0x20 mm/kmsan/kmsan_instr.c:54 vga_8planes_fillrect drivers/video/fbdev/vga16fb.c:855 [inline] vga16fb_fillrect+0xbbc/0x1870 drivers/video/fbdev/vga16fb.c:947 bit_clear_margins+0x582/0x740 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins drivers/video/fbdev/core/fbcon.c:1381 [inline] fbcon_switch+0x2e79/0x3830 drivers/video/fbdev/core/fbcon.c:2363 redraw_screen+0x9b2/0x2980 drivers/tty/vt/vt.c:1015 fbcon_modechanged+0x110d/0x1320 drivers/video/fbdev/core/fbcon.c:3001 fbcon_update_vcs+0x86/0xa0 drivers/video/fbdev/core/fbcon.c:3048 fb_set_var+0x1420/0x1850 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0xc00/0x1150 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0x1e4/0x210 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:48 [inline] ksys_ioctl fs/ioctl.c:753 [inline] __do_sys_ioctl fs/ioctl.c:762 [inline] __se_sys_ioctl+0x319/0x4d0 fs/ioctl.c:760 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:760 do_syscall_64+0xad/0x160 arch/x86/entry/common.c:386 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d5f9 Code: Bad RIP value. RSP: 002b:00007fdcda761c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000000e280 RCX: 000000000045d5f9 RDX: 00000000200000c0 RSI: 0000000000004601 RDI: 0000000000000003 RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 000000000169fb6f R14: 00007fdcda7629c0 R15: 000000000118cf4c ------------[ cut here ]------------ slab index 32768 out of bounds (558) for stack id 262b8000 WARNING: CPU: 0 PID: 5351 at lib/stackdepot.c:235 stack_depot_fetch+0x2d/0x60 lib/stackdepot.c:234 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.