[syzbot] [net?] BUG: unable to handle kernel paging request in bond_rr_gen_slave_id (2)

[syzbot <syzbot+e224b9d5803638de57d9@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    fee3e843b309 Merge tag 'bcachefs-2025-05-15' of git://evil..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15f342d4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=30181bfb60dbb0a9
dashboard link: https://syzkaller.appspot.com/bug?extid=e224b9d5803638de57d9
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-fee3e843.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bad9badea84a/vmlinux-fee3e843.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9aae70a5a85a/bzImage-fee3e843.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e224b9d5803638de57d9@syzkaller.appspotmail.com

BUG: unable to handle page fault for address: ffff8880d6bdf000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 1b001067 P4D 1b001067 PUD 0 
Oops: Oops: 0002 [#1] SMP KASAN NOPTI
CPU: 2 UID: 0 PID: 12899 Comm: syz.2.2035 Not tainted 6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:bond_rr_gen_slave_id+0x1df/0x260 drivers/net/bonding/bond_main.c:4996
Code: bc 24 f0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 7a 49 8b 84 24 f0 00 00 00 bb 01 00 00 00 <65> 0f c1 18 e8 b8 af 53 fb 83 c3 01 89 d8 5b 5d 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003c5f650 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffc90007111000
RDX: 1ffff110092e69ce RSI: ffffffff86679653 RDI: ffff888049734e70
RBP: ffff888049734000 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888049734d80
R13: 0000000000000000 R14: ffff888049734d80 R15: ffffc90003c5f9c0
FS:  00007fd2ddf556c0(0000) GS:ffff8880d6bdf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8880d6bdf000 CR3: 000000004bfa9000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bond_xdp_xmit_roundrobin_slave_get drivers/net/bonding/bond_main.c:5083 [inline]
 bond_xdp_get_xmit_slave+0x2a9/0x6b0 drivers/net/bonding/bond_main.c:5622
 xdp_master_redirect+0x15e/0x330 net/core/filter.c:4349
 bpf_prog_run_xdp include/net/xdp.h:657 [inline]
 xdp_test_run_batch.constprop.0+0x18c8/0x1f10 net/bpf/test_run.c:318
 bpf_test_run_xdp_live+0x34d/0x500 net/bpf/test_run.c:390
 bpf_prog_test_run_xdp+0x824/0x1540 net/bpf/test_run.c:1316
 bpf_prog_test_run kernel/bpf/syscall.c:4427 [inline]
 __sys_bpf+0x1488/0x4d80 kernel/bpf/syscall.c:5852
 __do_sys_bpf kernel/bpf/syscall.c:5941 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5939 [inline]
 __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5939
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd2dd18e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd2ddf55038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fd2dd3b5fa0 RCX: 00007fd2dd18e969
RDX: 0000000000000048 RSI: 0000200000000600 RDI: 000000000000000a
RBP: 00007fd2dd210ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd2dd3b5fa0 R15: 00007ffc29f1f808
 </TASK>
Modules linked in:
CR2: ffff8880d6bdf000
---[ end trace 0000000000000000 ]---
RIP: 0010:bond_rr_gen_slave_id+0x1df/0x260 drivers/net/bonding/bond_main.c:4996
Code: bc 24 f0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 7a 49 8b 84 24 f0 00 00 00 bb 01 00 00 00 <65> 0f c1 18 e8 b8 af 53 fb 83 c3 01 89 d8 5b 5d 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003c5f650 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffc90007111000
RDX: 1ffff110092e69ce RSI: ffffffff86679653 RDI: ffff888049734e70
RBP: ffff888049734000 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888049734d80
R13: 0000000000000000 R14: ffff888049734d80 R15: ffffc90003c5f9c0
FS:  00007fd2ddf556c0(0000) GS:ffff8880d6bdf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8880d6bdf000 CR3: 000000004bfa9000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 4 bytes skipped:
   0:	00 00                	add    %al,(%rax)
   2:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   9:	fc ff df
   c:	48 89 fa             	mov    %rdi,%rdx
   f:	48 c1 ea 03          	shr    $0x3,%rdx
  13:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
  17:	75 7a                	jne    0x93
  19:	49 8b 84 24 f0 00 00 	mov    0xf0(%r12),%rax
  20:	00
  21:	bb 01 00 00 00       	mov    $0x1,%ebx
* 26:	65 0f c1 18          	xadd   %ebx,%gs:(%rax) <-- trapping instruction
  2a:	e8 b8 af 53 fb       	call   0xfb53afe7
  2f:	83 c3 01             	add    $0x1,%ebx
  32:	89 d8                	mov    %ebx,%eax
  34:	5b                   	pop    %rbx
  35:	5d                   	pop    %rbp
  36:	41 5c                	pop    %r12
  38:	41 5d                	pop    %r13
  3a:	41 5e                	pop    %r14


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