=============================
WARNING: suspicious RCU usage
5.13.0-rc3-syzkaller #0 Not tainted
-----------------------------
kernel/sched/core.c:8304 Illegal context switch in RCU-bh 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.5/12530:
 #0: 
ffff888018e2a2d8
 (
&mm->mmap_lock
#2
){++++}-{3:3}
, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
, at: do_user_addr_fault+0x285/0x1210 arch/x86/mm/fault.c:1331

stack backtrace:
CPU: 1 PID: 12530 Comm: syz-executor.5 Not tainted 5.13.0-rc3-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+0x141/0x1d7 lib/dump_stack.c:120
 ___might_sleep+0x229/0x2c0 kernel/sched/core.c:8304
 process_huge_page mm/memory.c:5100 [inline]
 clear_huge_page+0x9c/0x560 mm/memory.c:5161
 __do_huge_pmd_anonymous_page mm/huge_memory.c:608 [inline]
 do_huge_pmd_anonymous_page+0x60e/0x2570 mm/huge_memory.c:771
 create_huge_pmd mm/memory.c:4238 [inline]
 __handle_mm_fault+0x2ffd/0x52c0 mm/memory.c:4473
 handle_mm_fault+0x1bc/0x7e0 mm/memory.c:4600
 do_user_addr_fault+0x483/0x1210 arch/x86/mm/fault.c:1390
 handle_page_fault arch/x86/mm/fault.c:1475 [inline]
 exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1531
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:577
RIP: 0033:0x407bea
Code: 30 48 8b 34 24 48 85 f6 74 17 8b 44 24 18 0f c8 89 c0 48 89 44 24 18 48 83 fe 01 0f 85 a1 01 00 00 48 8b 44 24 10 8b 74 24 18 <89> 30 e9 d2 fc ff ff 48 8b 44 24 10 8b 10 48 8b 04 24 48 85 c0 0f
RSP: 002b:00007ffc5afa2160 EFLAGS: 00010246
RAX: 00000000200000c0 RBX: 0000000000970000 RCX: 0000000000000000
RDX: d29fbfb3cac91cad RSI: 0000000000000000 RDI: 000000000344e2f0
RBP: 00007ffc5afa2258 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000004 R11: 00000000458a1cac R12: 0000000000048aaf
R13: 00000000000003e8 R14: 000000000056bf80 R15: 0000000000048aac