general protection fault in d_flags_for_inode

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 42e66b1cc3a0 Merge tag 'net-6.0-rc4' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17652ac7080000
kernel config: https://syzkaller.appspot.com/x/.config?x=1b99b64a317b9f1
dashboard link: https://syzkaller.appspot.com/bug?extid=6b4f1a0cdacbd30cebbf
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

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+6b4f1a...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 8177
loop0:
ntfs3: loop0: Different NTFS' sector size (4096) and media sector size (512)
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 2 PID: 6347 Comm: syz-executor.0 Not tainted 6.0.0-rc3-syzkaller-00107-g42e66b1cc3a0 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
RIP: 0010:d_flags_for_inode+0x21b/0x2a0 fs/dcache.c:1980
Code: 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 90 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 63 20 49 8d 7c 24 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 69 49 83 7c 24 08 00 75 34 e8 02 53 a0 ff 41 83 cd
RSP: 0000:ffffc9000507fb40 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888045ef7250 RCX: ffffc90003cc4000
RDX: 0000000000000001 RSI: ffffffff81dae5e2 RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000008 R14: ffff888077000000 R15: ffff888074f12088
FS: 00007f2500411700(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd02cec0350 CR3: 00000000760b4000 CR4: 0000000000150ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__d_instantiate+0x21/0x450 fs/dcache.c:1998
d_instantiate fs/dcache.c:2036 [inline]
d_instantiate fs/dcache.c:2030 [inline]
d_make_root+0xae/0x110 fs/dcache.c:2071
ntfs_fill_super+0x31eb/0x37f0 fs/ntfs3/super.c:1269
get_tree_bdev+0x440/0x760 fs/super.c:1323
vfs_get_tree+0x89/0x2f0 fs/super.c:1530
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x1326/0x1e20 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f24ff28a7aa
Code: 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2500410f88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007f24ff28a7aa
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f2500410fe0
RBP: 00007f2500411020 R08: 00007f2500411020 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 00007f2500410fe0 R15: 000000002007a1e0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:d_flags_for_inode+0x21b/0x2a0 fs/dcache.c:1980
Code: 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 90 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 63 20 49 8d 7c 24 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 69 49 83 7c 24 08 00 75 34 e8 02 53 a0 ff 41 83 cd
RSP: 0000:ffffc9000507fb40 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888045ef7250 RCX: ffffc90003cc4000
RDX: 0000000000000001 RSI: ffffffff81dae5e2 RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000008 R14: ffff888077000000 R15: ffff888074f12088
FS: 00007f2500411700(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd02cec0350 CR3: 00000000760b4000 CR4: 0000000000150ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 89 fa mov %edi,%edx
2: 48 c1 ea 03 shr $0x3,%rdx
6: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
a: 0f 85 90 00 00 00 jne 0xa0
10: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
17: fc ff df
1a: 4c 8b 63 20 mov 0x20(%rbx),%r12
1e: 49 8d 7c 24 08 lea 0x8(%r12),%rdi
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 75 69 jne 0x99
30: 49 83 7c 24 08 00 cmpq $0x0,0x8(%r12)
36: 75 34 jne 0x6c
38: e8 02 53 a0 ff callq 0xffa0533f
3d: 41 rex.B
3e: 83 .byte 0x83
3f: cd .byte 0xcd


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[syzbot]

Sending this report upstream.