=============================
WARNING: suspicious RCU usage
5.12.0-rc5-syzkaller #0 Not tainted
-----------------------------
kernel/sched/core.c:8294 Illegal context switch in RCU-sched read-side critical section!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 0
1 lock held by syz-executor.1/10259:
 #0: ffff8880199cf158 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff8880199cf158 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault+0x2d8/0x1120 arch/x86/mm/fault.c:1331

stack backtrace:
CPU: 1 PID: 10259 Comm: syz-executor.1 Not tainted 5.12.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x176/0x24e lib/dump_stack.c:120
 ___might_sleep+0xb4/0x530 kernel/sched/core.c:8294
 process_huge_page mm/memory.c:5051 [inline]
 clear_huge_page+0x208/0x8a0 mm/memory.c:5112
 __do_huge_pmd_anonymous_page+0x286/0xde0 mm/huge_memory.c:607
 do_huge_pmd_anonymous_page+0x552/0xac0 mm/huge_memory.c:772
 create_huge_pmd mm/memory.c:4189 [inline]
 __handle_mm_fault mm/memory.c:4424 [inline]
 handle_mm_fault+0x1fe4/0x2570 mm/memory.c:4551
 do_user_addr_fault+0x8ce/0x1120 arch/x86/mm/fault.c:1390
 handle_page_fault arch/x86/mm/fault.c:1475 [inline]
 exc_page_fault+0xa1/0x1e0 arch/x86/mm/fault.c:1531
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:577
RIP: 0033:0x461bea
Code: 6f 06 c5 fa 6f 4c 16 f0 c5 fa 7f 07 c5 fa 7f 4c 17 f0 c3 48 8b 4c 16 f8 48 8b 36 48 89 4c 17 f8 48 89 37 c3 8b 4c 16 fc 8b 36 <89> 4c 17 fc 89 37 c3 0f b7 4c 16 fe 0f b7 36 66 89 4c 17 fe 66 89
RSP: 002b:00007ffd382a3f08 EFLAGS: 00010202
RAX: 0000000020000040 RBX: 0000000000000003 RCX: 000000000073666d
RDX: 0000000000000006 RSI: 00000000666d6f72 RDI: 0000000020000040
RBP: 00007ffd382a3fc8 R08: 0000000000970000 R09: 0000000000000010
R10: 00007ffd382f10b8 R11: 0000000000007a08 R12: 0000000000000001
R13: 0000000000000000 R14: 000000000056bf60 R15: 0000000000026e37