#syz dup: WARNING: suspicious RCU usage in getname_flags
On Sat, Apr 03, 2021 at 07:35:16PM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:d19cc4bf Merge tag 'trace-v5.12-rc5' of git://git.kernel.o..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1611e681d0
> kernel config: https://syzkaller.appspot.com/x/.config?x=78ef1d159159890
> dashboard link: https://syzkaller.appspot.com/bug?extid=7a0c25f9520c969c15f5
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+7a0c25f9520c969c1...@syzkaller.appspotmail.com
>
> =
> WARNING: suspicious RCU usage
> 5.12.0-rc5-syzkaller #0 Not tainted
> -
> kernel/sched/core.c:8294 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.2/10002:
> #0: 8880129669d8 (>mmap_lock#2){}-{3:3}, at: mmap_read_trylock
> include/linux/mmap_lock.h:136 [inline]
> #0: 8880129669d8 (>mmap_lock#2){}-{3:3}, at:
> do_user_addr_fault+0x285/0x1210 arch/x86/mm/fault.c:1331
>
> stack backtrace:
> CPU: 0 PID: 10002 Comm: syz-executor.2 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+0x141/0x1d7 lib/dump_stack.c:120
> ___might_sleep+0x229/0x2c0 kernel/sched/core.c:8294
> process_huge_page mm/memory.c:5051 [inline]
> clear_huge_page+0x9c/0x560 mm/memory.c:5112
> __do_huge_pmd_anonymous_page mm/huge_memory.c:607 [inline]
> do_huge_pmd_anonymous_page+0x60e/0x2570 mm/huge_memory.c:772
> create_huge_pmd mm/memory.c:4189 [inline]
> __handle_mm_fault+0x2e59/0x4f70 mm/memory.c:4424
> handle_mm_fault+0x1bc/0x7e0 mm/memory.c:4551
> 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: 0033:0x461b6d
> Code: 48 01 d0 eb 0b 0f 1f 84 00 00 00 00 00 48 89 f8 48 83 fa 20 72 49 48 83
> fa 40 0f 87 9f 00 00 00 c5 fe 6f 06 c5 fe 6f 4c 16 e0 fe 7f 07 c5 fe 7f
> 4c 17 e0 c5 f8 77 c3 48 3b 15 7e 8e 04 01 0f
> RSP: 002b:7fffc28c60c8 EFLAGS: 00010287
> RAX: 2080 RBX: 0003 RCX: 0057
> RDX: 002b RSI: 00570020 RDI: 2080
> RBP: 7fffc28c6188 R08: 0097 R09: 7fffc2907090
> R10: a8e8 R11: R12: 0001
> R13: R14: 0056bf60 R15: 00035790
>
>
> ---
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