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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Jonathan Corbet , Shuah Khan , Randy Dunlap , Peter Xu , Breno Leitao , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Peter Zijlstra , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Arnd Bergmann , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Gerd Hoffmann , linux-doc@vger.kernel.org, linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, luojiajun , Josef Bacik , stable@kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <497E3E4E-B423-46FA-AB00-5D2ABFB833A0@linux.dev> References: <20261028-fixes_hugetlb-v1-0-a0a033db180f@kernel.org> <20261028-fixes_hugetlb-v1-1-a0a033db180f@kernel.org> To: "David Hildenbrand (Arm)" X-Mailer: Apple Mail (2.3901.100.1.1.12) X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 9150F1C0005 X-Stat-Signature: ic6huw79we8ydo5p3xdbydkjyed6eq91 X-Rspam-User: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-HE-Tag: 1793245047-743526 X-HE-Meta: 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 Ej2AiXsr BEEmFcrHGcmdbvebWH1sfMepvoOJutyIhc4S+PJwB4np/Ke2mzfBDWR2DR5TgRb7UaoOAQ/+++h1yO30ebpc+qnNpQ7JrCrh/57TTbsALPWte2oEmINZFB9MBNS4bI6KyRgH7GaGElkHcwWx/poudwl9kdaL22sl/pdelskLJPy6tafcch4mhq7CzCvTiZZCPnpKORicft6L50by+jDZ2o4vbGUIV2DHfCNwiVr3ILaFvEBbOZG8HQ+7k9CwTbRuJekhMMEWzApA7xMaTfn3HewnXENvzsOFo3OCnSmjYrDk3GPWDLh8MLL+YGJ+E02WTgKZ5xbk79GakPGWtSDHZiowQm+pQkIaG4tginPgmPF1b/6cwPODqKXqPFIvjA0xXakF5SD10wv3yHTuNGlbJq1kYTt2LjnNZow59jzsaIeztbL9nKWl/cFkQRB8CAkc6oSSR Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 > On Oct 29, 2026, at 04:13, David Hildenbrand (Arm) = wrote: >=20 > hugetlbfs_fallocate() rounds the range end up by adding hpage_size - 1 > to offset + len. vfs_fallocate()'s existing overflow check only makes > sure that offset + len does not overflow. >=20 > Once we overflow for valid endpoints near LLONG_MAX, we can get a > negative temporary result that is then converted to a very large > huge page index. >=20 > A one-byte allocation ending at LLONG_MAX can therefore consume all > available huge pages. Pages added beyond LLONG_MAX are skipped during > inode eviction, leaking them and triggering the BUG_ON() in = clear_inode(). >=20 > To fix it, calculate the end index in a simpler way that cannot > overflow. This also fixes the signed overflow reported by luojiajun in > 2019. Amazing that you remember something from so long ago! >=20 > Backporting notes: without commit a08c7193e4f18 ("mm/filemap: remove > hugetlb special casing in filemap.c"), remove_inode_hugepages() must > include the final huge page during truncate and eviction. >=20 > Reported-by: luojiajun > Closes: = https://lore.kernel.org/all/1554775226-67213-1-git-send-email-luojiajun3@h= uawei.com/ > Reported-by: Josef Bacik > Fixes: 70c3547e36f5 ("hugetlbfs: add hugetlbfs_fallocate()") > Cc: stable@kernel.org > Signed-off-by: David Hildenbrand (Arm) LGTM. Acked-by: Muchun Song Thanks.