[syzbot] [bcachefs?] general protection fault in gen_poly_key

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4a4be1ad3a6e Revert "vfs: Delete the associated dentry whe..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11ae4d14980000
kernel config: https://syzkaller.appspot.com/x/.config?x=238430243a58f702
dashboard link: https://syzkaller.appspot.com/bug?extid=0c7a9c4a5a4b3730d4f6
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=101c3162980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1432099a980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-4a4be1ad.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e90895495e65/vmlinux-4a4be1ad.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9e28d1589c72/bzImage-4a4be1ad.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/83e4344d1bf8/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0c7a9c...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc000000903d: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: probably user-memory-access in range [0x00000000000481e8-0x00000000000481ef]
CPU: 1 PID: 5189 Comm: syz-executor842 Not tainted 6.10.0-rc1-syzkaller-00027-g4a4be1ad3a6e #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:gen_poly_key.isra.0+0x10d/0x330 fs/bcachefs/checksum.c:191
Code: 00 00 00 00 05 00 00 00 80 89 44 24 0c e8 db 56 f0 fd 49 8d bd e8 81 04 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ce 01 00 00 4c 89 fa 4d 8b 8d e8 81 04 00 48 b8
RSP: 0018:ffffc900031eee48 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 1ffff9200063ddcb RCX: 0000000000000000
RDX: 000000000000903d RSI: 0000000000000000 RDI: 00000000000481e8
RBP: ffffc900031eef20 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc900031eee98 R11: 0000000000000000 R12: ffffc900031eee98
R13: 0000000000000000 R14: ffffc900031ef028 R15: ffffc900031eee84
FS: 0000555568ecb380(0000) GS:ffff88806b100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055954aed89d8 CR3: 00000000236b0000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
bch2_checksum+0x1f9/0x2e0 fs/bcachefs/checksum.c:227
read_one_super+0x567/0x1530 fs/bcachefs/super-io.c:672
__bch2_read_super+0xc81/0x12a0 fs/bcachefs/super-io.c:797
bch2_fs_open+0x3e5/0x1110 fs/bcachefs/super.c:2070
bch2_mount+0xdcc/0x1130 fs/bcachefs/fs.c:1917
legacy_get_tree+0x109/0x220 fs/fs_context.c:662
vfs_get_tree+0x8f/0x380 fs/super.c:1780
do_new_mount fs/namespace.c:3352 [inline]
path_mount+0x14e6/0x1f20 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount fs/namespace.c:3875 [inline]
__x64_sys_mount+0x297/0x320 fs/namespace.c:3875
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc8c1cf78fa
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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:00007ffdfeaaa7e8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffdfeaaa800 RCX: 00007fc8c1cf78fa
RDX: 0000000020005d80 RSI: 0000000020005dc0 RDI: 00007ffdfeaaa800
RBP: 0000000000000004 R08: 00007ffdfeaaa840 R09: 0000000000005d9b
R10: 0000000000000480 R11: 0000000000000282 R12: 0000000000000480
R13: 00007ffdfeaaa840 R14: 0000000000000003 R15: 0000000001000000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:gen_poly_key.isra.0+0x10d/0x330 fs/bcachefs/checksum.c:191
Code: 00 00 00 00 05 00 00 00 80 89 44 24 0c e8 db 56 f0 fd 49 8d bd e8 81 04 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ce 01 00 00 4c 89 fa 4d 8b 8d e8 81 04 00 48 b8
RSP: 0018:ffffc900031eee48 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 1ffff9200063ddcb RCX: 0000000000000000
RDX: 000000000000903d RSI: 0000000000000000 RDI: 00000000000481e8
RBP: ffffc900031eef20 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc900031eee98 R11: 0000000000000000 R12: ffffc900031eee98
R13: 0000000000000000 R14: ffffc900031ef028 R15: ffffc900031eee84
FS: 0000555568ecb380(0000) GS:ffff88806b100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055954aed89d8 CR3: 00000000236b0000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 00 add %al,(%rax)
4: 05 00 00 00 80 add $0x80000000,%eax
9: 89 44 24 0c mov %eax,0xc(%rsp)
d: e8 db 56 f0 fd call 0xfdf056ed
12: 49 8d bd e8 81 04 00 lea 0x481e8(%r13),%rdi
19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
20: fc ff df
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: 0f 85 ce 01 00 00 jne 0x202
34: 4c 89 fa mov %r15,%rdx
37: 4d 8b 8d e8 81 04 00 mov 0x481e8(%r13),%r9
3e: 48 rex.W
3f: b8 .byte 0xb8


---
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