[syzbot] WARNING in change_pte_range

[syzbot] WARNING in change_pte_range

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    511cce163b75 Merge tag 'net-6.0-rc8' of git://git.kernel.o..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=155eade4880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4520785fccee9b40
dashboard link: https://syzkaller.appspot.com/bug?extid=2c2bb573a9524a95e787
compiler:       Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14ecac35080000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15668b38880000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2c2bb573a9524a95e787@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 3607 at include/linux/swapops.h:323 change_pte_range+0x11f4/0x1ab0 mm/mprotect.c:271
Modules linked in:
CPU: 0 PID: 3607 Comm: syz-executor171 Not tainted 6.0.0-rc7-syzkaller-00130-g511cce163b75 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
RIP: 0010:make_pte_marker_entry include/linux/swapops.h:323 [inline]
RIP: 0010:make_pte_marker include/linux/swapops.h:346 [inline]
RIP: 0010:change_pte_range+0x11f4/0x1ab0 mm/mprotect.c:271
Code: e8 c1 02 bd ff 4c 8b 74 24 18 49 bd 00 00 00 00 00 fc ff df e9 8d fc ff ff e8 a8 02 bd ff 0f 0b e9 72 f4 ff ff e8 9c 02 bd ff <0f> 0b 48 8d 9c 24 00 01 00 00 48 c1 eb 03 42 80 3c 2b 00 74 0d 48
RSP: 0018:ffffc9000399f580 EFLAGS: 00010293
RAX: ffffffff81cc93c4 RBX: 0000000000000000 RCX: ffff88801fdfbb00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000399f728 R08: ffffffff81cc8706 R09: ffffed10045001a1
R10: ffffed10045001a1 R11: 1ffff110045001a0 R12: 000000002063d000
R13: dffffc0000000000 R14: ffff888027d251e8 R15: ffff888027d251e8
FS:  000055555742e300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000005d84c8 CR3: 000000007a01e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 change_pmd_range mm/mprotect.c:409 [inline]
 change_pud_range mm/mprotect.c:438 [inline]
 change_p4d_range mm/mprotect.c:459 [inline]
 change_protection_range mm/mprotect.c:483 [inline]
 change_protection+0xc1f/0x16d0 mm/mprotect.c:505
 uffd_wp_range mm/userfaultfd.c:718 [inline]
 mwriteprotect_range+0x50c/0x5a0 mm/userfaultfd.c:768
 userfaultfd_writeprotect fs/userfaultfd.c:1827 [inline]
 userfaultfd_ioctl+0x2733/0x3230 fs/userfaultfd.c:1999
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fbc63941bb9
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff43ddba98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbc63941bb9
RDX: 00000000200000c0 RSI: 00000000c018aa06 RDI: 0000000000000003
RBP: 00007fbc63905d60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbc63905df0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>


---
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Re: [syzbot] WARNING in change_pte_range

[syzbot]

syzbot has bisected this issue to:

commit b1f9e876862d8f7176299ec4fb2108bc1045cbc8
Author: Peter Xu <peterx@redhat.com>
Date:   Fri May 13 03:22:56 2022 +0000

    mm/uffd: enable write protection for shmem & hugetlbfs

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=108e8fb8880000
start commit:   511cce163b75 Merge tag 'net-6.0-rc8' of git://git.kernel.o..
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=128e8fb8880000
console output: https://syzkaller.appspot.com/x/log.txt?x=148e8fb8880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4520785fccee9b40
dashboard link: https://syzkaller.appspot.com/bug?extid=2c2bb573a9524a95e787
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14ecac35080000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15668b38880000

Reported-by: syzbot+2c2bb573a9524a95e787@syzkaller.appspotmail.com
Fixes: b1f9e876862d ("mm/uffd: enable write protection for shmem & hugetlbfs")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: [syzbot] WARNING in change_pte_range

[Peter Xu]

On Fri, Oct 07, 2022 at 03:08:22PM -0700, syzbot wrote:
> syzbot has bisected this issue to:
> 
> commit b1f9e876862d8f7176299ec4fb2108bc1045cbc8
> Author: Peter Xu <peterx@redhat.com>
> Date:   Fri May 13 03:22:56 2022 +0000
> 
>     mm/uffd: enable write protection for shmem & hugetlbfs
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=108e8fb8880000
> start commit:   511cce163b75 Merge tag 'net-6.0-rc8' of git://git.kernel.o..
> git tree:       upstream
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=128e8fb8880000
> console output: https://syzkaller.appspot.com/x/log.txt?x=148e8fb8880000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=4520785fccee9b40
> dashboard link: https://syzkaller.appspot.com/bug?extid=2c2bb573a9524a95e787
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14ecac35080000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15668b38880000
> 
> Reported-by: syzbot+2c2bb573a9524a95e787@syzkaller.appspotmail.com
> Fixes: b1f9e876862d ("mm/uffd: enable write protection for shmem & hugetlbfs")
> 
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> 

#syz dup: WARNING in change_protection

-- 
Peter Xu