Message-ID: <000000000000479d8d05a49221b1@google.com>
Date:   Fri, 01 May 2020 01:40:14 -0700
From:   syzbot <syzbot+0bfda3ade1ee9288a1be@...kaller.appspotmail.com>
To:     daniel.vetter@...ll.ch, gregkh@...uxfoundation.org,
        jslaby@...e.com, linux-kernel@...r.kernel.org, nico@...xnic.net,
        sam@...nborg.org, syzkaller-bugs@...glegroups.com
Subject: kernel BUG at arch/x86/mm/physaddr.c:LINE! (5)

Hello,

syzbot found the following crash on:

HEAD commit:    6a8b55ed Linux 5.7-rc3
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1447420fe00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1ac152749c11ca54
dashboard link: https://syzkaller.appspot.com/bug?extid=0bfda3ade1ee9288a1be
compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12db1b80100000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15efcb80100000

The bug was bisected to:

commit 9a98e7a80f95378c9ee0c644705e3b5aa54745f1
Author: Nicolas Pitre <nico@...xnic.net>
Date:   Sun Mar 29 02:25:11 2020 +0000

    vt: don't use kmalloc() for the unicode screen buffer

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16bb967fe00000
final crash:    https://syzkaller.appspot.com/x/report.txt?x=15bb967fe00000
console output: https://syzkaller.appspot.com/x/log.txt?x=11bb967fe00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0bfda3ade1ee9288a1be@...kaller.appspotmail.com
Fixes: 9a98e7a80f95 ("vt: don't use kmalloc() for the unicode screen buffer")

------------[ cut here ]------------
kernel BUG at arch/x86/mm/physaddr.c:28!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 7061 Comm: syz-executor995 Not tainted 5.7.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__phys_addr+0x10e/0x120 arch/x86/mm/physaddr.c:28
Code: 6b 89 80 e1 07 38 c1 0f 8c 75 ff ff ff 48 c7 c7 85 a3 6b 89 e8 f3 a8 7d 00 e9 64 ff ff ff e8 b9 c5 3f 00 0f 0b e8 b2 c5 3f 00 <0f> 0b e8 ab c5 3f 00 0f 0b 66 0f 1f 84 00 00 00 00 00 53 48 89 fb
RSP: 0018:ffffc900016579f8 EFLAGS: 00010093
RAX: ffffffff81339bbe RBX: 0000000000000001 RCX: ffff88808dd5a340
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 00000000ffffffea R08: ffffffff81339b2c R09: ffffed1015d27074
R10: ffffed1015d27074 R11: 0000000000000000 R12: ffffc900016c9000
R13: dffffc0000000000 R14: 00004080016c9000 R15: ffffffff83fad568
FS:  0000000001f5d880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000043e7d0 CR3: 0000000099a6c000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 virt_to_head_page include/linux/mm.h:833 [inline]
 virt_to_cache mm/slab.h:474 [inline]
 kfree+0x60/0x220 mm/slab.c:3749
 vc_do_resize+0x738/0x1ce0 drivers/tty/vt/vt.c:1233
 vt_ioctl+0x3178/0x3eb0 drivers/tty/vt/vt_ioctl.c:901
 tty_ioctl+0xee4/0x15c0 drivers/tty/tty_io.c:2656
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x443f99
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffcf0b9f6f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443f99
RDX: 0000000020000080 RSI: 000000000000560a RDI: 0000000000000004
RBP: 00000000006ce018 R08: 000000000000000d R09: 00000000004002e0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401ca0
R13: 0000000000401d30 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 7662909635649ec0 ]---
RIP: 0010:__phys_addr+0x10e/0x120 arch/x86/mm/physaddr.c:28
Code: 6b 89 80 e1 07 38 c1 0f 8c 75 ff ff ff 48 c7 c7 85 a3 6b 89 e8 f3 a8 7d 00 e9 64 ff ff ff e8 b9 c5 3f 00 0f 0b e8 b2 c5 3f 00 <0f> 0b e8 ab c5 3f 00 0f 0b 66 0f 1f 84 00 00 00 00 00 53 48 89 fb
RSP: 0018:ffffc900016579f8 EFLAGS: 00010093
RAX: ffffffff81339bbe RBX: 0000000000000001 RCX: ffff88808dd5a340
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 00000000ffffffea R08: ffffffff81339b2c R09: ffffed1015d27074
R10: ffffed1015d27074 R11: 0000000000000000 R12: ffffc900016c9000
R13: dffffc0000000000 R14: 00004080016c9000 R15: ffffffff83fad568
FS:  0000000001f5d880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000043e7d0 CR3: 0000000099a6c000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This bug 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@...glegroups.com.

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For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

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