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b=S415AHNc03IacdvQbnISEPk2z1abb4XVpEac+IYMKNL9F1T65+bfcN7/vL7fDcTGs k1Xo6TYD8kyRb+MZZ3ENaTNByGpWEMCVtiTRgVFpKqGzqgqNQ9xtVnHXPClP9EXaPb PECYEHpyJ0oY5f5i58xKCWrexuNtdvWil+ULjWJky+EIZAFDD9KzhG6ukX2rHZdAUo 5gR4E1/5hHfaq6mcMKV5dynarDuH78p69AqniiNyE+bVzTOR/s0fGUp5yKAX4ED7Eg dZ511PZk/USgwGcq3z4JmYrxjbQgP0Mg+QR2tQ3utqOU8kUjgz5FZuHPp5FCHexA66 w9vJIQ8e/3Plg== From: Pratyush Yadav To: Yifei Chu Cc: Pasha Tatashin , Mike Rapoport , linux-kernel@vger.kernel.org, Pratyush Yadav , Andrew Morton , Alexander Graf , linux-mm@kvack.org, kexec@lists.infradead.org Subject: Re: [BUG] liveupdate/memfd: duplicate memfd preserve restores same KHO folio twice In-Reply-To: (Yifei Chu's message of "Sun, 24 May 2026 10:44:40 -0400") References: Date: Mon, 25 May 2026 17:30:34 +0200 Message-ID: <2vxzfr3f7bhh.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Stat-Signature: dr99uyignnwizpuffcwn3ed1iwju7suj X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 9183A40015 X-HE-Tag: 1779723038-51118 X-HE-Meta: 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 DOxHqhB9 PezqtbolV08eeTs02wxFhVBtsU/CwAJotCYPNYQjtvm/eyzzK79nvNQf3DHGxcT+vRrhQ0aucIsDBehIN3EaN6M8jqDCnZsf1DfaNJio21NgDsRuTBZVhGVUIZ8zVkq0qxUMYfx1+wigpFm2T6h3vP/OpHMFuctIk2D8S61fiJ7kRLpcdieE+/YyxUPIvLyxxR2+B Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sun, May 24 2026, Yifei Chu wrote: > Hello, > > Short version: I found that the same memfd can be preserved more than once in a single liveupdate session under different > tokens. After kexec, those tokens can both refer to the same preserved KHO folio, and the second restore path hits > kho_restore_page(). With panic_on_warn=1, this is a reproducible panic. Pasha fixed this with 00d0b372374f ("liveupdate: prevent double management of files"). It landed in v7.1-rc1. Since you seem to be using 7.0.9, please port this patch to the 7.0.y series and try again. If this fixes the problem, please send it to stable@vger.kernel.org so it can be included in the 7.0.y series. -- Regards, Pratyush Yadav