Re: [moderation/CI] Re: coredump/fcntl: Add FD_CLOBCOR flag to close fd before dumping core

#syz upstream


On Thu, Jun 18, 2026 at 6:29 AM syzbot ci
<[email protected]> wrote:
>
> syzbot ci has tested the following series
>
> [v1] coredump/fcntl: Add FD_CLOBCOR flag to close fd before dumping core
> https://lore.kernel.org/all/[email protected]
> * [PATCH] coredump/fcntl: Add FD_CLOBCOR flag to close fd before dumping core
>
> and found the following issue:
> WARNING: suspicious RCU usage in exit_files_before_core
>
> Full report is available here:
> https://ci.syzbot.org/series/bda032a0-64d8-4226-8ad1-6a4c99514d61
>
> ***
>
> WARNING: suspicious RCU usage in exit_files_before_core
>
> tree:      torvalds
> URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
> base:      2a706d98d50a28dd635b3d028531d839c1f5f19a
> arch:      amd64
> compiler:  Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
> config:    https://ci.syzbot.org/builds/e0dd4cce-02a0-415c-9720-8816ca17346d/config
>
> =============================
> WARNING: suspicious RCU usage
> syzkaller #0 Not tainted
> -----------------------------
> ./include/linux/fdtable.h:104 suspicious rcu_dereference_check() usage!
>
> other info that might help us debug this:
>
>
> rcu_scheduler_active = 2, debug_locks = 1
> no locks held by syz.2.65/5687.
>
> stack backtrace:
> CPU: 0 UID: 0 PID: 5687 Comm: syz.2.65 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> Call Trace:
>  <TASK>
>  dump_stack_lvl+0xe8/0x150
>  lockdep_rcu_suspicious+0x13f/0x1d0
>  exit_files_before_core+0x35a/0x410
>  vfs_coredump+0xa52/0x4550
>  get_signal+0x1107/0x1330
>  arch_do_signal_or_restart+0xbc/0x830
>  irqentry_exit+0x2a4/0x860
>  asm_exc_page_fault+0x26/0x30
> RIP: 0033:0x0
> Code: Unable to access opcode bytes at 0xffffffffffffffd6.
> RSP: 002b:0000200000000008 EFLAGS: 00010217
> RAX: 0000000000000000 RBX: 00007f3125415fa0 RCX: 00007f312519ce59
> RDX: 0000200000000000 RSI: 0000200000000000 RDI: 0000000000000000
> RBP: 00007f3125232d6f R08: 0000200000000000 R09: 0000000000000000
> R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007f3125415fac R14: 00007f3125415fa0 R15: 00007f3125415fa0
>  </TASK>
>
>
> ***
>
> If these findings have caused you to resend the series or submit a
> separate fix, please add the following tag to your commit message:
>   Tested-by: [email protected]
>
> ---
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