syzbot

=============================
WARNING: suspicious RCU usage
5.13.0-rc5-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.1/12754:
 #0: 
ffff888035405558
 (
&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: 12754 Comm: syz-executor.1 Not tainted 5.13.0-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+0x141/0x1d7 lib/dump_stack.c:120
 ___might_sleep+0x229/0x2c0 kernel/sched/core.c:8304
 process_huge_page mm/memory.c:5104 [inline]
 clear_huge_page+0x9c/0x560 mm/memory.c:5165
 __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:4242 [inline]
 __handle_mm_fault+0x2ffd/0x52c0 mm/memory.c:4477
 handle_mm_fault+0x1bc/0x7e0 mm/memory.c:4604
 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: 0033:0x461d5b
Code: 80 fa 01 77 3b 72 05 0f b6 0e 88 0f c3 c5 fa 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
RSP: 002b:0000000000a9fb98 EFLAGS: 00010206
RAX: 0000000020004600 RBX: 0000000000000003 RCX: 00237265646e6962
RDX: 000000000000000d RSI: 6e69622f7665642f RDI: 0000000020004600
RBP: 0000000000a9fc58 R08: 0000000000970000 R09: 00007ffe9b92d080
R10: 00007ffe9b92d090 R11: 000000000000aba8 R12: 0000000000000001
R13: 0000000000000000 R14: 000000000056bf80 R15: 00000000000369f6