================================================
WARNING: lock held when returning to user space!
syzkaller #0 Not tainted
------------------------------------------------
udevd/5820 is leaving the kernel with locks still held!
1 lock held by udevd/5820:
#0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290
BUG: sleeping function called from invalid context at ./include/linux/sched/mm.h:323
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5820, name: udevd
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
INFO: lockdep is turned off.
CPU: 0 UID: 0 PID: 5820 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
__might_resched+0x329/0x480 kernel/sched/core.c:9162
might_alloc include/linux/sched/mm.h:323 [inline]
prepare_alloc_pages+0x1f0/0x6b0 mm/page_alloc.c:4995
__alloc_frozen_pages_noprof+0x12f/0x380 mm/page_alloc.c:5215
alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2490
folio_alloc_mpol_noprof+0x3b/0x1e0 mm/mempolicy.c:2509
vma_alloc_folio_noprof+0xe1/0x1e0 mm/mempolicy.c:2544
folio_prealloc mm/memory.c:-1 [inline]
wp_page_copy mm/memory.c:3859 [inline]
do_wp_page+0x1109/0x3d90 mm/memory.c:4320
handle_pte_fault mm/memory.c:6427 [inline]
__handle_mm_fault mm/memory.c:6549 [inline]
handle_mm_fault+0xaee/0x14c0 mm/memory.c:6718
do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fa47a8a9c40
Code: 64 24 08 75 ea 48 83 c4 38 5b 5d 41 5c 41 5d 41 5e 41 5f c3 66 0f 1f 44 00 00 42 f6 44 10 08 01 0f 84 04 01 00 00 48 83 e6 fe <48> 89 70 08 49 8b 47 70 49 89 5f 70 66 48 0f 6e c0 48 89 58 18 0f
RSP: 002b:00007ffdcd772cb0 EFLAGS: 00010206
RAX: 000055a857dc6100 RBX: 000055a857dc60e0 RCX: 0000000000000001
RDX: 000055a857dbde50 RSI: 0000000000000300 RDI: 000055a857dc5530
RBP: 0000000000000020 R08: 0000000000000001 R09: 000055a857dc4170
R10: 0000000000000300 R11: 0000000000000297 R12: 00007fa47a9e5ad0
R13: 000055ad0d593cb6 R14: 000000055a857dc6 R15: 00007fa47a9e5ac0
------------[ cut here ]------------
Voluntary context switch within RCU read-side critical section!
WARNING: kernel/rcu/tree_plugin.h:332 at rcu_note_context_switch+0xcac/0xf40 kernel/rcu/tree_plugin.h:332, CPU#0: udevd/5820
Modules linked in:
CPU: 0 UID: 0 PID: 5820 Comm: udevd Tainted: G W syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:rcu_note_context_switch+0xcac/0xf40 kernel/rcu/tree_plugin.h:332
Code: 00 41 c6 45 00 00 48 8b 3d 31 93 e2 0d 48 81 c4 b8 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d e9 9b 60 ff ff 48 8d 3d b4 5b e6 0d <67> 48 0f b9 3a e9 1b f4 ff ff 90 0f 0b 90 45 84 e4 0f 84 ea f3 ff
RSP: 0018:ffffc9000453f7b0 EFLAGS: 00010002
RAX: 0000000000000000 RBX: ffff888036c99ec0 RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8ba845c0 RDI: ffffffff8f90bbf0
RBP: dffffc0000000000 R08: ffffffff8f8d45f7 R09: 1ffffffff1f1a8be
R10: dffffc0000000000 R11: fffffbfff1f1a8bf R12: 0000000000000000
R13: ffff888036c99ec0 R14: ffff8880b863c980 R15: ffff888036c9a384
FS: 00007fa47a7ad880(0000) GS:ffff888125eb6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a857dc8da8 CR3: 000000002ac0a000 CR4: 00000000003526f0
Call Trace:
__schedule+0x297/0x54f0 kernel/sched/core.c:7043
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7282
schedule_hrtimeout_range_clock+0x1f2/0x330 kernel/time/sleep_timeout.c:207
ep_poll fs/eventpoll.c:2032 [inline]
do_epoll_wait+0xa7a/0xbd0 fs/eventpoll.c:2466
__do_sys_epoll_wait fs/eventpoll.c:2474 [inline]
__se_sys_epoll_wait fs/eventpoll.c:2469 [inline]
__x64_sys_epoll_wait+0x1d7/0x230 fs/eventpoll.c:2469
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa47a89b407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffdcd77b8d0 EFLAGS: 00000202 ORIG_RAX: 00000000000000e8
RAX: ffffffffffffffda RBX: 00007fa47a7ad880 RCX: 00007fa47a89b407
RDX: 0000000000000004 RSI: 00007ffdcd77b960 RDI: 0000000000000004
RBP: 000055a857dae910 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000202 R12: 000055a857de5c80
R13: 00007ffdcd77b960 R14: 0000000000000000 R15: 0000000000000004
----------------
Code disassembly (best guess):
0: 00 41 c6 add %al,-0x3a(%rcx)
3: 45 00 00 add %r8b,(%r8)
6: 48 8b 3d 31 93 e2 0d mov 0xde29331(%rip),%rdi # 0xde2933e
d: 48 81 c4 b8 00 00 00 add $0xb8,%rsp
14: 5b pop %rbx
15: 41 5c pop %r12
17: 41 5d pop %r13
19: 41 5e pop %r14
1b: 41 5f pop %r15
1d: 5d pop %rbp
1e: e9 9b 60 ff ff jmp 0xffff60be
23: 48 8d 3d b4 5b e6 0d lea 0xde65bb4(%rip),%rdi # 0xde65bde
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: e9 1b f4 ff ff jmp 0xfffff44f
34: 90 nop
35: 0f 0b ud2
37: 90 nop
38: 45 84 e4 test %r12b,%r12b
3b: 0f .byte 0xf
3c: 84 ea test %ch,%dl
3e: f3 repz
3f: ff .byte 0xff