[syzbot] general protection fault in do_swap_page (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    e3d35712 Add linux-next specific files for 20210423
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14b953f5d00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e370221d7500b26a
dashboard link: https://syzkaller.appspot.com/bug?extid=9bedf8ef6e51e0bb3401

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+9bedf8ef6e51e0bb3401@xxxxxxxxxxxxxxxxxxxxxxxxx

get_swap_device: Bad swap file entry 3fffa5f80000a
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 8451 Comm: syz-fuzzer Not tainted 5.12.0-rc8-next-20210423-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:do_swap_page+0x9fa/0x2430 mm/memory.c:3349
Code: e8 bb a2 6d 07 e9 cb fa ff ff e8 01 c1 cb ff 48 8b 7c 24 10 e8 97 b7 0a 00 48 ba 00 00 00 00 00 fc ff df 48 89 c1 48 c1 e9 03 <80> 3c 11 00 0f 85 60 17 00 00 48 8b 18 31 ff 81 e3 00 10 00 00 48
RSP: 0000:ffffc900015ffc78 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880124035b0 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff81b3f0de RDI: 0000000000000003
RBP: ffffc900015ffd88 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81b3f09f R11: 0000000000000000 R12: 0000000000000000
R13: ffff888029ea0e00 R14: ffff888024424040 R15: 0000000000000000
FS:  000000c00027c490(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001000000 CR3: 0000000014778000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 handle_pte_fault mm/memory.c:4371 [inline]
 __handle_mm_fault+0x1b8b/0x5150 mm/memory.c:4502
 handle_mm_fault+0x1bc/0x7e0 mm/memory.c:4600
 do_user_addr_fault+0x483/0x1210 arch/x86/mm/fault.c:1390
 handle_page_fault arch/x86/mm/fault.c:1475 [inline]
 exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1531
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:577
RIP: 0033:0x420a5d
Code: 0c 48 ff c7 d1 eb 48 83 c6 08 0f 1f 00 48 83 ff 08 0f 8d f9 00 00 00 48 39 f1 0f 86 f0 00 00 00 0f ba e3 00 73 db 4c 8d 04 16 <4d> 8b 00 4d 85 c0 74 cf 48 89 7c 24 40 4c 89 44 24 38 48 89 74 24
RSP: 002b:000000c0002bde18 EFLAGS: 00010203
RAX: 00007fafa7949000 RBX: 0000000000000009 RCX: 0000000000040000
RDX: 0000000000fcd820 RSI: 00000000000327e0 RDI: 0000000000000004
RBP: 000000c0002bde68 R08: 0000000001000000 R09: 0000000000000045
R10: 0000000001880e68 R11: 0000000000000053 R12: 0000000000000003
R13: 000000c000082780 R14: 000000000000000f R15: 0000000000000c96
Modules linked in:
---[ end trace bfcda609218a3121 ]---
RIP: 0010:do_swap_page+0x9fa/0x2430 mm/memory.c:3349
Code: e8 bb a2 6d 07 e9 cb fa ff ff e8 01 c1 cb ff 48 8b 7c 24 10 e8 97 b7 0a 00 48 ba 00 00 00 00 00 fc ff df 48 89 c1 48 c1 e9 03 <80> 3c 11 00 0f 85 60 17 00 00 48 8b 18 31 ff 81 e3 00 10 00 00 48
RSP: 0000:ffffc900015ffc78 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880124035b0 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff81b3f0de RDI: 0000000000000003
RBP: ffffc900015ffd88 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81b3f09f R11: 0000000000000000 R12: 0000000000000000
R13: ffff888029ea0e00 R14: ffff888024424040 R15: 0000000000000000
FS:  000000c00027c490(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c000c7c010 CR3: 0000000014778000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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@xxxxxxxxxxxxxxxx.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.