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([138.199.21.246]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2c743bfe8aasm104014885ad.68.2026.06.23.07.32.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Jun 2026 07:32:26 -0700 (PDT) From: Jing Wu To: gregkh@linuxfoundation.org Cc: jirislaby@kernel.org, avorontsov@ru.mvista.com, alan@redhat.com, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, wangzhaolong@fnnas.com Subject: Re: [PATCH v4] serial: 8250: fix use-after-free in IRQ chain handling Date: Tue, 23 Jun 2026 22:32:20 +0800 Message-ID: <20260623143220.432877-1-realwujing@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <2026061213-blinker-portable-a198@gregkh> References: <20260529-bug-221579-8250-shared-irq-race-v4-1-cfda63b4420f@gmail.com> <2026061213-blinker-portable-a198@gregkh> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Qiliang Yuan On Fri, Jun 12, 2026 at 11:49:51AM +0200, Greg Kroah-Hartman wrote: > What real systems causes this to happen? How are you triggering this > warning to happen? How was this tested? The original report is Bugzilla #221579 from Wang Zhaolong. The bug triggers on systems with multiple 8250 serial ports sharing an IRQ (e.g. NAS-like devices). It can be reproduced by probing/removing 8250 serial ports that share an IRQ. Wang confirmed off-list that v3 fixes the reproducer on his setup. > Shouldn't the function be marked as requiring this lock to be held? > Just putting in this lockdep_assert will not catch the static analysis > tools :( Agreed, will add __must_hold(&hash_mutex) in v5. Thanks, Qiliang