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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-47a957de489sm114389375e9.5.2025.12.14.05.54.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 14 Dec 2025 05:54:42 -0800 (PST) Date: Sun, 14 Dec 2025 13:54:40 +0000 From: David Laight To: Ma Ke Cc: krzk@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, aloisio.almeida@openbossa.org, lauro.venancio@openbossa.org, sameo@linux.intel.com, linville@tuxdriver.com, johannes@sipsolutions.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, stable@vger.kernel.org Subject: Re: [PATCH] NFC: Fix error handling in nfc_genl_dump_targets Message-ID: <20251214135440.51409316@pumpkin> In-Reply-To: <20251214131726.5353-1-make24@iscas.ac.cn> References: <20251214131726.5353-1-make24@iscas.ac.cn> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sun, 14 Dec 2025 21:17:26 +0800 Ma Ke wrote: > nfc_genl_dump_targets() increments the device reference count via > nfc_get_device() but fails to decrement it properly. nfc_get_device() > calls class_find_device() which internally calls get_device() to > increment the reference count. No corresponding put_device() is made > to decrement the reference count. > > Add proper reference count decrementing using nfc_put_device() when > the dump operation completes or encounters an error, ensuring balanced > reference counting. > > Found by code review. Is that some half-hearted AI code review? Isn't the 'put' done by nfc_genl_dump_targets_done() which it looks like the outer code calls sometime later on. David > > Cc: stable@vger.kernel.org > Fixes: 4d12b8b129f1 ("NFC: add nfc generic netlink interface") > Signed-off-by: Ma Ke > --- > net/nfc/netlink.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c > index a18e2c503da6..9ae138ee91dd 100644 > --- a/net/nfc/netlink.c > +++ b/net/nfc/netlink.c > @@ -159,6 +159,11 @@ static int nfc_genl_dump_targets(struct sk_buff *skb, > > cb->args[0] = i; > > + if (rc < 0 || i >= dev->n_targets) { > + nfc_put_device(dev); > + cb->args[1] = 0; > + } > + > return skb->len; > } >