[syzbot] general protection fault in d_flags_for_inode

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 1a61b828566f Merge tag 'char-misc-6.0-rc7' of git://git.ke..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=125f60d4880000
kernel config: https://syzkaller.appspot.com/x/.config?x=122d7bd4fc8e0ecb
dashboard link: https://syzkaller.appspot.com/bug?extid=2f012b85ac8ce9be92e5
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13153c4c880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=156e2650880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/367e34e7ff83/disk-1a61b828.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/91a2819fe451/vmlinux-1a61b828.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2f012b...@syzkaller.appspotmail.com

ntfs3: loop0: Different NTFS' sector size (2048) and media sector size (512)
ntfs3: loop0: RAW NTFS volume: Filesystem size 0.00 Gb > volume size 0.00 Gb. Mount in read-only
ntfs3: loop0: Failed to load $Extend.
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 3605 Comm: syz-executor204 Not tainted 6.0.0-rc6-syzkaller-00309-g1a61b828566f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
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 82 95 9f ff 41 83 cd
RSP: 0018:ffffc900039afb40 EFLAGS: 00010212
RAX: dffffc0000000000 RBX: ffff888072cad370 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff81dc7352 RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000008 R14: ffff8880700a0000 R15: ffff888020d02088
FS: 0000555556e83300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd13507000 CR3: 000000007498a000 CR4: 0000000000350ee0
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: 0033:0x7fa9945b147a
Code: 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 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:00007ffd13506ac8 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffd13506b20 RCX: 00007fa9945b147a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffd13506ae0
RBP: 00007ffd13506ae0 R08: 00007ffd13506b20 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000286 R12: 0000000020000320
R13: 0000000000000003 R14: 0000000000000004 R15: 000000000000000c
</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 82 95 9f ff 41 83 cd
RSP: 0018:ffffc900039afb40 EFLAGS: 00010212
RAX: dffffc0000000000 RBX: ffff888072cad370 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff81dc7352 RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000008 R14: ffff8880700a0000 R15: ffff888020d02088
FS: 0000555556e83300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd13507000 CR3: 000000007498a000 CR4: 0000000000350ee0
----------------
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 82 95 9f ff callq 0xff9f95bf
3d: 41 rex.B
3e: 83 .byte 0x83
3f: cd .byte 0xcd


---
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[syzbot]

syzbot suspects this issue was fixed by commit:

commit c43784c856483dded7956175b5786e27af6d87f1
Author: Hans Verkuil <hverkui...@xs4all.nl>
Date: Thu Dec 8 07:51:32 2022 +0000

media: v4l2-mem2mem: use vb2_is_streaming()

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17e7d1bca80000
start commit: 4da34b7d175d Merge tag 'thermal-6.1-rc2' of git://git.kern..
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=ea03ca45176080bc
dashboard link: https://syzkaller.appspot.com/bug?extid=2f012b85ac8ce9be92e5
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17834f9a880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10edf526880000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: media: v4l2-mem2mem: use vb2_is_streaming()

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

[Aleksandr Nogikh]

On Thu, Jul 13, 2023 at 11:37 AM syzbot
<syzbot+2f012b...@syzkaller.appspotmail.com> wrote:
>
> syzbot suspects this issue was fixed by commit:
>
> commit c43784c856483dded7956175b5786e27af6d87f1
> Author: Hans Verkuil <hverkui...@xs4all.nl>
> Date: Thu Dec 8 07:51:32 2022 +0000
>
> media: v4l2-mem2mem: use vb2_is_streaming()
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17e7d1bca80000

No, that's apparently unrelated. Though I don't see where exactly the
bisection went astray..
Likely because the reproducer got quite unreliable at older commits
and we made a few false "git bisect good" commands.

We will soon start automatically discarding such bisection results:
https://github.com/google/syzkaller/pull/4028

> start commit: 4da34b7d175d Merge tag 'thermal-6.1-rc2' of git://git.kern..
> git tree: upstream
> kernel config: https://syzkaller.appspot.com/x/.config?x=ea03ca45176080bc
> dashboard link: https://syzkaller.appspot.com/bug?extid=2f012b85ac8ce9be92e5
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17834f9a880000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10edf526880000
>
> If the result looks correct, please mark the issue as fixed by replying with:
>
> #syz fix: media: v4l2-mem2mem: use vb2_is_streaming()

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

> --

[syzbot]

Auto-closing this bug as obsolete.
No recent activity, existing reproducers are no longer triggering the issue.