WARNING in pin_user_pages_locked

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    a804ab08 Add linux-next specific files for 20201006
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1688db0b900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
dashboard link: https://syzkaller.appspot.com/bug?extid=542e00ce34515318e08e
compiler:       gcc (GCC) 10.1.0-syz 20200507
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15ab0c77900000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17d2c33f900000

The issue was bisected to:

commit d53807afc288c71eb9374f102d49cc01f6b6c760
Author: Daniel Vetter <daniel.vetter@xxxxxxxx>
Date:   Sat Oct 3 08:01:38 2020 +0000

    mm/frame-vec: use FOLL_LONGTERM

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=164d7c68500000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=154d7c68500000
console output: https://syzkaller.appspot.com/x/log.txt?x=114d7c68500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+542e00ce34515318e08e@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: d53807afc288 ("mm/frame-vec: use FOLL_LONGTERM")

------------[ cut here ]------------
WARNING: CPU: 0 PID: 6893 at mm/gup.c:2992 pin_user_pages_locked+0x60d/0x780 mm/gup.c:2992
Modules linked in:
CPU: 0 PID: 6893 Comm: syz-executor513 Not tainted 5.9.0-rc8-next-20201006-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:pin_user_pages_locked+0x60d/0x780 mm/gup.c:2992
Code: cf ff 49 83 c7 08 e8 22 2e cf ff 48 8b 44 24 10 c6 44 24 10 01 48 05 00 10 00 00 48 89 44 24 08 e9 65 fb ff ff e8 03 2e cf ff <0f> 0b 49 c7 c4 ea ff ff ff e9 8a fe ff ff e8 f0 2d cf ff 0f 0b 49
RSP: 0018:ffffc900011c7648 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000010000 RCX: ffffffff81a61358
RDX: ffff8880a6822000 RSI: ffffffff81a6192d RDI: 0000000000000005
RBP: ffffc900011c7728 R08: ffffc900011c7728 R09: ffff88808e116307
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000110 R14: 0000000000000110 R15: ffff888092918010
FS:  00000000024e4880(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f91c63cc028 CR3: 00000000a7259000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 get_vaddr_frames+0x788/0x960 mm/frame_vector.c:75
 vb2_create_framevec+0x55/0xc0 drivers/media/common/videobuf2/videobuf2-memops.c:50
 vb2_vmalloc_get_userptr+0xce/0x4c0 drivers/media/common/videobuf2/videobuf2-vmalloc.c:90
 __prepare_userptr+0x342/0x15f0 drivers/media/common/videobuf2/videobuf2-core.c:1117
 __buf_prepare+0x635/0x7d0 drivers/media/common/videobuf2/videobuf2-core.c:1356
 vb2_core_qbuf+0xa9d/0x11c0 drivers/media/common/videobuf2/videobuf2-core.c:1647
 vb2_qbuf+0x135/0x1a0 drivers/media/common/videobuf2/videobuf2-v4l2.c:826
 vb2_ioctl_qbuf+0xfb/0x140 drivers/media/common/videobuf2/videobuf2-v4l2.c:1056
 v4l_qbuf drivers/media/v4l2-core/v4l2-ioctl.c:2066 [inline]
 v4l_qbuf+0x92/0xc0 drivers/media/v4l2-core/v4l2-ioctl.c:2060
 __video_do_ioctl+0xb94/0xe20 drivers/media/v4l2-core/v4l2-ioctl.c:2990
 video_usercopy+0x207/0xe50 drivers/media/v4l2-core/v4l2-ioctl.c:3306
 v4l2_ioctl+0x1b3/0x250 drivers/media/v4l2-core/v4l2-dev.c:360
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x443ff9
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 fb d7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd1306b5e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443ff9
RDX: 0000000020000140 RSI: 00000000c058560f RDI: 0000000000000003
RBP: 00000000006ce018 R08: 00000000004002e0 R09: 00000000004002e0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401c80
R13: 0000000000401d10 R14: 0000000000000000 R15: 0000000000000000


---
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