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[35.245.46.111]) by smtp.gmail.com with ESMTPSA id 00721157ae682-8b05abda9ffsm9529857b3.39.2026.10.07.07.48.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Oct 2026 07:48:47 -0700 (PDT) Date: Wed, 07 Oct 2026 10:48:47 -0400 From: Willem de Bruijn To: Josef Bacik , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Kaiyuan Zhang , Mina Almasry , Willem de Bruijn Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, Josef Bacik Message-ID: In-Reply-To: <20261006-b4-skbuff-bug-on-v1-0-1b4434c5357c@toxicpanda.com> References: <20261006-b4-skbuff-bug-on-v1-0-1b4434c5357c@toxicpanda.com> Subject: Re: [PATCH net-next 0/9] net: skbuff: convert most BUG_ON()s to WARN_ON_ONCE() and an error Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Josef Bacik wrote: > I'm going through and reducing BUG_ON() usage in areas that have created > the most problems for us. 89 commits in the tree quote "kernel BUG at > net/core/skbuff.c", 31 of them since 2024, and some of those could be > triggered from inside a user namespace. > > The first patch is a fix: skb_copy_and_csum_bits() leaves stale bytes > in a buffer headed for the wire when it hits unreadable frags. The > BUG_ON() conversion of the same function needs the same handling, so > it's here rather than sent separately. > > The rest of the series converts 17 of the 19 BUG_ON()s in skbuff.c. > Each one becomes > > if (WARN_ON_ONCE(cond)) > ; Good idea. I was thinking of doing exactly this sweep after addressing one case recently in commit ee1972def665 ("net: downgrade BUG_ON EIOCBQUEUED in sock_sendmsg_nosec") Instead of WARN_ON_ONCE, which still triggers a panic on systems with panic_on_warn, DEBUG_NET_WARN_ON_ONCE?