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b=RABhSdjt5u0xspCBftMJSAFcLnZnPAxEHcgKblhAtxk2MraxplpKc7uBljDlCqvPp zVTmMAHY2/KZRj0OAGoDXPHwZ+Nz/QC/QyXVkUoI3+bv01bgaAmOBagGDm/e+3tbEP jLCLsdybfirYpTfIb9IwBkU4e8p6QlLTxhuA+21yf/lM9yB9+6Xp9rflfRKcdut2K+ lGcvKjYnZgffXWdfk55VUWJGpgDn6MHoKiIEuplqxepYfj8mGRLipvfmd+VoUHNXbg 7lVlEA2UGcrQYxZpwhnGXh8LcxvUOIk8TDsf9KruXsGr8chSDyJ6nePwJzrUXnlhNJ bZcj708UaTX5w== 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: incoming/outgoing session ioctls accepted in wrong phase can panic In-Reply-To: (Yifei Chu's message of "Sun, 24 May 2026 10:44:31 -0400") References: Date: Mon, 25 May 2026 17:26:51 +0200 Message-ID: <2vxzjysr7bno.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Stat-Signature: e4kcfq7oy9jd7rzsg4egd3igqf4twgj8 X-Rspamd-Queue-Id: A969C16000B X-Rspamd-Server: rspam07 X-Rspam-User: X-HE-Tag: 1779722815-781479 X-HE-Meta: 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 4bmIGysh rk7QTeyQ3jE0FOblwdyw+v2hf2hqXMW7vIknA7phUff8ejpbAnhr8X4v3/2nsHsxSOAzniCGAI9nZz90n/oGObXzKLqDcd4JhgkLUXKf8MVfgAhjnBWVZk5PHxbJB6LsW7jmaPyI3IWKnv8NCcSieItgDufCVhgBAGzic+fZPnfestkwjHnzPRhZjKCQPOsiNIqh1iaS7AC/rK6v+kLPLgERptSt6L21u6l+o 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 liveupdate session ioctls can be accepted on the wrong kind of session. In my tests, that > lets userspace drive memfd LUO into KHO restore paths for current-kernel preserved memory, which hits kho_restore_page() > warnings and panics with panic_on_warn=1. I already sent a fix for this: https://lore.kernel.org/kexec/20260519122428.2378446-1-pratyush@kernel.org/ I need to do a refresh of this patch with some tests. -- Regards, Pratyush Yadav