From nobody Wed Dec 17 23:17:11 2025 Received: from sgoci-sdnproxy-4.icoremail.net (sgoci-sdnproxy-4.icoremail.net [129.150.39.64]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1A8CB4CDE0; Thu, 2 May 2024 23:36:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=129.150.39.64 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714693011; cv=none; b=MivoRU4yCbYSxIcokDEVmGkspRBUL7iDZSgVoOt24rncZfX84Dmc6zS0ak0TSBCreY+MdXzU4aJ1Bu6ETh6TpKM2mVe8YKlVm2fnW3oyFkDggt2c5Cjzk8SMiOXhrv1mrYMoAOUP5WnovRYV8tx8ZGBmne0xzXhEae4BSFGtLPU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714693011; c=relaxed/simple; bh=Fjn0sWcJSSpaNhOq3cT/DmSa0Heykx1LsFKm4zCLDGg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: In-Reply-To:References; b=hgvwzWqroqzZSiaMC8XvKoOQ6C3yhymT39WQplQouS3jU61UfnZHN2n3GGhq9/19ZJrwXVXg0bxlztKtQlz8YwHopYs4fxTFcMNIxQrOLqcCbi3QJq3ND3IB3MW22NE7FM9RVZHac+GP+od6DnDhffxxEgIVwMePLHHEZM7HcXE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=zju.edu.cn; spf=pass smtp.mailfrom=zju.edu.cn; arc=none smtp.client-ip=129.150.39.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=zju.edu.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zju.edu.cn Received: from ubuntu.localdomain (unknown [221.192.179.227]) by mail-app2 (Coremail) with SMTP id by_KCgC3ZqZwIzRm7PwDAA--.6463S4; Fri, 03 May 2024 07:36:26 +0800 (CST) From: Duoming Zhou To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-hams@vger.kernel.org, pabeni@redhat.com, kuba@kernel.org, edumazet@google.com, davem@davemloft.net, jreuter@yaina.de, horms@kernel.org, Markus.Elfring@web.de, dan.carpenter@linaro.org, lars@oddbit.com, Duoming Zhou Subject: [PATCH net v2 2/2] ax25: fix potential reference counting leak in ax25_addr_ax25dev Date: Fri, 3 May 2024 07:36:16 +0800 Message-Id: <74e840d98f2bfc79c6059993b2fc1ed3888faba4.1714690906.git.duoming@zju.edu.cn> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-CM-TRANSID: by_KCgC3ZqZwIzRm7PwDAA--.6463S4 X-Coremail-Antispam: 1UD129KBjvdXoW7GrWrAF18GFyrZw17XF45GFg_yoWDZFc_ua s7ury7Ww1DJr1jkw1rXF48Jry7Zw1vgwn7Ar1ayFZ7trWYqa47JrWkJwn8XFyUWFy7Cr4S qF1rGrW3Cw4SkjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbl8FF20E14v26rWj6s0DM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUXwA2048vs2IY02 0Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVWxJVW8Jr1l84 ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I2 62IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcV AFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG 0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxcIEc7CjxVA2Y2ka0xkIwI 1lc7CjxVAaw2AFwI0_Jw0_GFylc2xSY4AK67AK6FWl42xK82IYc2Ij64vIr41l4c8EcI0E c7CjxVAaw2AFwI0_Jw0_GFyl4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxV WUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI 7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r 4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI 42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfUbE_MUUUUU X-CM-SenderInfo: qssqjiasttq6lmxovvfxof0/1tbiAwUJAWYztgkCSgAMsg Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The reference counting of ax25_dev potentially increase more than once in ax25_addr_ax25dev(), which will cause memory leak. In order to fix the above issue, only increase the reference counting of ax25_dev once, when the res is not null. Fixes: d01ffb9eee4a ("ax25: add refcount in ax25_dev to avoid UAF bugs") Reported-by: Dan Carpenter Signed-off-by: Duoming Zhou --- net/ax25/ax25_dev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ax25/ax25_dev.c b/net/ax25/ax25_dev.c index 07723095c60..7c2ea7309b0 100644 --- a/net/ax25/ax25_dev.c +++ b/net/ax25/ax25_dev.c @@ -37,8 +37,9 @@ ax25_dev *ax25_addr_ax25dev(ax25_address *addr) for (ax25_dev =3D ax25_dev_list; ax25_dev !=3D NULL; ax25_dev =3D ax25_de= v->next) if (ax25cmp(addr, (const ax25_address *)ax25_dev->dev->dev_addr) =3D=3D = 0) { res =3D ax25_dev; - ax25_dev_hold(ax25_dev); } + if (res) + ax25_dev_hold(res); spin_unlock_bh(&ax25_dev_lock); =20 return res; --=20 2.17.1