============================= WARNING: suspicious RCU usage 5.13.0-rc2-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.3/10378: #0: ffff88808670a458 ( &mm->mmap_lock #2 ){++++}-{3:3} , at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] , at: do_user_addr_fault+0x2d8/0x1120 arch/x86/mm/fault.c:1331 stack backtrace: CPU: 0 PID: 10378 Comm: syz-executor.3 Not tainted 5.13.0-rc2-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+0x202/0x31e lib/dump_stack.c:120 ___might_sleep+0xce/0x6b0 kernel/sched/core.c:8304 process_huge_page mm/memory.c:5100 [inline] clear_huge_page+0x208/0x8a0 mm/memory.c:5161 __do_huge_pmd_anonymous_page+0x2df/0xe80 mm/huge_memory.c:608 do_huge_pmd_anonymous_page+0x654/0xce0 mm/huge_memory.c:771 create_huge_pmd mm/memory.c:4238 [inline] __handle_mm_fault mm/memory.c:4473 [inline] handle_mm_fault+0x207e/0x2620 mm/memory.c:4600 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: 0010:copy_user_generic_unrolled+0x89/0xc0 arch/x86/lib/copy_user_64.S:92 Code: 38 4c 89 47 20 4c 89 4f 28 4c 89 57 30 4c 89 5f 38 48 8d 76 40 48 8d 7f 40 ff c9 75 b6 89 d1 83 e2 07 c1 e9 03 74 12 4c 8b 06 <4c> 89 07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10 89 d1 8a RSP: 0018:ffffc90017277e28 EFLAGS: 00010202 RAX: ffffffff83fc1201 RBX: 0000000020000148 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffc90017277ea0 RDI: 0000000020000140 RBP: ffffc90017277f10 R08: 0000000400000003 R09: fffff52002e4efd5 R10: fffff52002e4efd5 R11: 0000000000000000 R12: 0000000000000008 R13: 00007ffffffff000 R14: ffffc90017277ea0 R15: 0000000020000140 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] _copy_to_user+0xef/0x130 lib/usercopy.c:33 copy_to_user include/linux/uaccess.h:200 [inline] do_pipe2+0xc2/0x2b0 fs/pipe.c:994 __do_sys_pipe fs/pipe.c:1015 [inline] __se_sys_pipe fs/pipe.c:1013 [inline] __x64_sys_pipe+0x36/0x40 fs/pipe.c:1013 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665d9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f435535a188 EFLAGS: 00000246 ORIG_RAX: 0000000000000016 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000140 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffdd39807af R14: 00007f435535a300 R15: 0000000000022000