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AJvYcCU0BE0zVhWn96jdE4At+peE61xOvWmmpBt5mf9bzqggntXjArTalqhSYJJxKKysoN4S1UufyO//2+tecQ==@vger.kernel.org X-Gm-Message-State: AOJu0YxJk52KbHTU30iq83yKRM72/Cs/ncY28AWonwmUUk7o0jbd7+sZ UmzcCSPA4yp6gsCS3B2dNmnP8sV92Mx60QdFcCnyIAN4A73PqZ0M/FCkouA8559Zpub10NE4i9T WU86bFL89ROmJeAgN383xrKV/bKf1o4M= X-Gm-Gg: ATEYQzys8mBuEaXsWZi9W5wz0pLKqj91YLt4sGr7MG3RY+MA4EbSIOmfClViy80orHc 9Rzog0vY5oQSolayPE7GOShQxAAG59pDcEGAqoLvjkdpCmkc7DzNeF7tvk4T6DxSrxFNmj9DuHO HdQoZGGIgZgtOf0um+KWSdxsDf46uK2u4wC4eCz3xn16CI3/Jg3W/SFgvQjyoUR68Rl5hJUZTy6 1SzItAQjp7btc4V5zDUKCvIOAKxyoyHf38nc4yZkt2cdm0gARjL4W8OCARZvjQNTor+3QVG+NiH t0Ny1jDfWc/sUUmiy1OwGoXQxzjCax91D/kvcz2v+unfaDgermZ1aiw= X-Received: by 2002:a17:907:d58e:b0:b97:aba7:1969 with SMTP id a640c23a62f3a-b982f3cbc95mr969518366b.45.1774320825565; Mon, 23 Mar 2026 19:53:45 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20260314123741.1439792-1-gality369@gmail.com> <20260323173340.GM5735@twin.jikos.cz> In-Reply-To: <20260323173340.GM5735@twin.jikos.cz> From: ZhengYuan Huang Date: Tue, 24 Mar 2026 10:53:33 +0800 X-Gm-Features: AQROBzA3OZEa-dxTDTdEcvGHBdv4WQwWgEJqtaoHs_l1lZe8HHeVOpaJt1H8iPk Message-ID: Subject: Re: [PATCH v2 0/3] btrfs: fix balance NULL derefs and chunk/bg mapping verification To: dsterba@suse.cz Cc: dsterba@suse.com, clm@fb.com, idryomov@gmail.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, baijiaju1990@gmail.com, r33s3n6@gmail.com, zzzccc427@gmail.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, Mar 24, 2026 at 1:33=E2=80=AFAM David Sterba wrot= e: > As I understand it you're using some advanced fuzzing tool (patch 1 > mentions runtime fuzzing), so the errors would not normally happen. With > fuzzing it depends on the capabilities, at runtime it is possible to > confuse the filesystem so much that sipmle checks can't detect it. > > Here checking if block group lookups are ok makes sense in general. > There are existing checks that seem to be following the same logic like > in unpin_extent_range(). Thanks for your review. Yes, we are using an in-house runtime fuzzing tool. However, after further investigation of this bug, we found that it is not limited to fuzzing-only scenarios. The issue can be reliably triggered by using a crafted filesystem image together with normal syscalls= . So this may not be purely a fuzzing artifact, but rather a potential robustness issue that could be hit in practice. > This is good, thanks. For simple fixes or cleanups it's fine to > make a vague reference to the main patch or a "in the previous/followup > patches". Thanks for the guidance, I=E2=80=99ll continue to follow this convention fo= r changelogs. Thanks, ZhengYuan Huang