BUG: unable to handle page fault for address: fffff91ffffff920
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 23ffe5067 P4D 23ffe5067 PUD 1cb13067 PMD 1cb14067 PTE 0
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
CPU: 1 UID: 0 PID: 7859 Comm: syz.2.478 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:rcu_segcblist_restempty kernel/rcu/rcu_segcblist.h:105 [inline]
RIP: 0010:rcu_segcblist_advance+0x7e/0x420 kernel/rcu/rcu_segcblist.c:474
Code: 48 8d 7b 08 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 1a 03 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 63 08 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 0d 03 00 00 49 8b 04 24 48 85 c0 0f 84 93 01 00
RSP: 0018:ffffc9001f587748 EFLAGS: 00010012
RAX: dffffc0000000000 RBX: ffffe8ffffc835c0 RCX: dffffc0000000000
RDX: 1ffffd1ffffff920 RSI: fffffffffffffe70 RDI: ffffe8ffffc835c8
RBP: 0000000000000246 R08: 4b21b045db16ba9e R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffffe8ffffffc900
R13: ffff888047484388 R14: ffffe8ffffc83540 R15: ffffe8ffffc835c0
FS: 00007f8716a936c0(0000) GS:ffff8881247b3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffff91ffffff920 CR3: 00000000782f1000 CR4: 0000000000350ef0
Call Trace:
<TASK>
srcu_gp_start_if_needed+0x30f/0xe70 kernel/rcu/srcutree.c:1318
__call_srcu kernel/rcu/srcutree.c:1391 [inline]
__synchronize_srcu+0x257/0x290 kernel/rcu/srcutree.c:1443
bch2_fs_btree_iter_exit+0x451/0x5f0 fs/bcachefs/btree_iter.c:3750
__bch2_fs_free fs/bcachefs/super.c:617 [inline]
bch2_fs_release+0x181/0xa10 fs/bcachefs/super.c:667
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x1e7/0x5a0 lib/kobject.c:737
bch2_fs_get_tree+0xd5e/0x1b70 fs/bcachefs/fs.c:2604
vfs_get_tree+0x8e/0x340 fs/super.c:1815
do_new_mount fs/namespace.c:3808 [inline]
path_mount+0x1513/0x2000 fs/namespace.c:4123
do_mount fs/namespace.c:4136 [inline]
__do_sys_mount fs/namespace.c:4347 [inline]
__se_sys_mount fs/namespace.c:4324 [inline]
__x64_sys_mount+0x28d/0x310 fs/namespace.c:4324
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8715b9066a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8716a92e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f8716a92ef0 RCX: 00007f8715b9066a
RDX: 0000200000000100 RSI: 0000200000000180 RDI: 00007f8716a92eb0
RBP: 0000200000000100 R08: 00007f8716a92ef0 R09: 0000000000200414
R10: 0000000000200414 R11: 0000000000000246 R12: 0000200000000180
R13: 00007f8716a92eb0 R14: 0000000000005ad0 R15: 0000200000001440
</TASK>
Modules linked in:
CR2: fffff91ffffff920
---[ end trace 0000000000000000 ]---
RIP: 0010:rcu_segcblist_restempty kernel/rcu/rcu_segcblist.h:105 [inline]
RIP: 0010:rcu_segcblist_advance+0x7e/0x420 kernel/rcu/rcu_segcblist.c:474
Code: 48 8d 7b 08 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 1a 03 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 63 08 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 0d 03 00 00 49 8b 04 24 48 85 c0 0f 84 93 01 00
RSP: 0018:ffffc9001f587748 EFLAGS: 00010012
RAX: dffffc0000000000 RBX: ffffe8ffffc835c0 RCX: dffffc0000000000
RDX: 1ffffd1ffffff920 RSI: fffffffffffffe70 RDI: ffffe8ffffc835c8
RBP: 0000000000000246 R08: 4b21b045db16ba9e R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffffe8ffffffc900
R13: ffff888047484388 R14: ffffe8ffffc83540 R15: ffffe8ffffc835c0
FS: 00007f8716a936c0(0000) GS:ffff8881247b3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffff91ffffff920 CR3: 00000000782f1000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
0: 48 8d 7b 08 lea 0x8(%rbx),%rdi
4: 48 89 fa mov %rdi,%rdx
7: 48 c1 ea 03 shr $0x3,%rdx
b: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
f: 0f 85 1a 03 00 00 jne 0x32f
15: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
1c: fc ff df
1f: 4c 8b 63 08 mov 0x8(%rbx),%r12
23: 4c 89 e2 mov %r12,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 0f 85 0d 03 00 00 jne 0x341
34: 49 8b 04 24 mov (%r12),%rax
38: 48 85 c0 test %rax,%rax
3b: 0f .byte 0xf
3c: 84 .byte 0x84
3d: 93 xchg %eax,%ebx
3e: 01 00 add %eax,(%rax)