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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Jiayuan Chen <jiayuan.chen@linux.dev>
Cc: netdev@vger.kernel.org, jiayuna.chen@linux.dev, jiayuna.chen@shopee.com,
	Jiayuan Chen <jiayuan.chen@shopee.com>,
	syzbot+80e046b8da2820b6ba73@syzkaller.appspotmail.com,
	Jay Vosburgh <jv@jvosburgh.net>,
	Andrew Lunn <andrew+netdev@lunn.ch>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Simon Horman <horms@kernel.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Jesper Dangaard Brouer <hawk@kernel.org>,
	John Fastabend <john.fastabend@gmail.com>,
	Stanislav Fomichev <sdf@fomichev.me>,
	Andrii Nakryiko <andrii@kernel.org>,
	Eduard Zingerman <eddyz87@gmail.com>,
	Martin KaFai Lau <martin.lau@linux.dev>, Song Liu <song@kernel.org>,
	Yonghong Song <yonghong.song@linux.dev>,
	KP Singh <kpsingh@kernel.org>, Hao Luo <haoluo@google.com>,
	Jiri Olsa <jolsa@kernel.org>, Shuah Khan <shuah@kernel.org>,
	Clark Williams <clrkwllms@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Jussi Maki <joamaki@gmail.com>, linux-kernel@vger.kernel.org,
	bpf@vger.kernel.org, linux-kselftest@vger.kernel.org,
	linux-rt-devel@lists.linux.dev
Subject: Re: [PATCH net v2 1/2] bonding: fix null-ptr-deref in
 bond_rr_gen_slave_id()
Message-ID: <20260227102149.10ZgLF-t@linutronix.de>
References: <20260227092254.272603-1-jiayuan.chen@linux.dev>
 <20260227092254.272603-2-jiayuan.chen@linux.dev>
 <20260227094558._Fna2iSe@linutronix.de>
 <4cc373b555ec3d6ff57037c569d12966a8b701db@linux.dev>
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In-Reply-To: <4cc373b555ec3d6ff57037c569d12966a8b701db@linux.dev>

On 2026-02-27 10:17:29 [+0000], Jiayuan Chen wrote:
> bond_mode can be changed after device creation via sysfs or netlink, a bond created
> in active-backup mode can later be switched to round-robin, which means the allocation
> must not be conditional on the mode at creation time.

Must the device be in down state or can this be also changed while the
device is up?

Sebastian