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h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Hh5PLXpv5/rcoN0VZaOLprddInBoOxdrtKPj8uYQo+VzSQcyZAU2ZNQ3Kqt2My1qX /520Dy+VoiNeqPY5l/1x2zlBC6dLkRDxm6cGczTHN8N8Gr4biMl9ZkZKfHFtPNJR/M AxZd75YD1uEaQr1hKEINql/b/YbZC2nZett8lwHI= Received: from pcnci.linuxbox.cz (pcnci.linuxbox.cz [10.76.3.14]) by linuxbox.linuxbox.cz (Sendmail) with ESMTPS id 69JFMeGg012171 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 19 Oct 2026 17:22:40 +0200 Received: from pcnci.linuxbox.cz (localhost [127.0.0.1]) by pcnci.linuxbox.cz (8.18.1/8.15.2) with ESMTPS id 69JFMbH63191394 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Mon, 19 Oct 2026 17:22:39 +0200 Date: Mon, 19 Oct 2026 17:22:37 +0200 From: Nikola Ciprich To: Andrew Morton Cc: Sean Christopherson , Borislav Petkov , David Laight , Rik van Riel , ljs@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, david@kernel.org, Mike Rapoport , Dave Hansen , Pedro Falcato , Kiryl Shutsemau , luizcap@redhat.com, pbonzini@redhat.com, Tal Zussman , Matt Fleming , Nikola Ciprich Subject: Re: hunting memory corruption bug in 6.18.x Message-ID: References: <20261014235736.GCatAW8GD0GlYumL4l@fat_crate.local> <20261015172820.7961d2c0def74d41cc6c4b0c@linux-foundation.org> <20261016031242.GDatGWKo98YSOhEOOn@fat_crate.local> <20261015211832.45d87fab15bb3e0bbc2f47cb@linux-foundation.org> <20261016054954.GEatG7AgMNFRkiTo1H@fat_crate.local> <20261018201538.d0957878f378a9821852836f@linux-foundation.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Scanned-By: MIMEDefang 3.7.1 on 10.76.66.3 X-Scanned-By: MIMEDefang v3.7.1/SpamAssassin v4.000002 on lbxovapx9 (nik) X-Scanned-By: MIMEDefang 2.86 on 10.76.66.10 X-Antivirus: on lbxovapx9 by Antivirus X-Spam-Score: N/A (trusted relay) X-Milter-Copy-Status: O X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: EB32816000D X-Stat-Signature: 6uezyg3yj4ahjifxagkmypgytwe4g3na X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_BLOCKED,RCVD_IN_ZEN_BLOCKED_OPENDNS, SPF_HELO_PASS,SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-Rspam-User: X-HE-Tag: 1792423379-237211 X-HE-Meta: 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 t3NrLHbn PfrurR0m7AM4PUwy7ftrh47VyjSk3DVji5E53P/XsJzpkoNRN/M8nXHE2ZnKwccbuVbhN453icq/IwWpf2+1/CoN91M1fkbxPddBlYdFVSXcdfK7tHKGPqYIk32NNmNZYyMRDvs9GOEEvhnCsDcu0KRK37XFzlv72TmisV7TZwOPilNaOmZrrR4JEy2b8c23CaJUl5+HURMU0rP14fMjovr09m0xLWXByLkXmq9Xfmzw3Hfcism1P6/PYHD/C8n0zX7qWN1slnx6u9OS5xI//nH8jTISx2E6r2hel1TsII/ziQ3FAJjnupQL3Vpew7KOj4oJrXQOWl5R07JyohHxhh6Pho42ErVK1qYXEr3pCU3GygKlZmonteMhmmvbU9zD6JK1y 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 > > Sure! And I have more good news: after applying 55780d8a1dcc > to 6.18.56, I was able to perform more than 30 migrations without > a glitch. After booting back into 6.18.56 without it, both VMs > crashed within 2-3 migrations. Furthermore, some memory apparently > got corrupted on one of the hosts, since various commands started > crashing too: > > [ 303.466091] traps: systemd-logind[3085] trap invalid opcode ip:7f7b5667e616 sp:7ffe1afdec38 error:0 in libsystemd-shared-252.so[7e616,7f7b5666d000+22e000] > [ 303.493810] traps: systemd-coredum[11269] trap invalid opcode ip:7fc6bf67f614 sp:7ffc075da958 error:0 in libsystemd-shared-252.so[7f614,7fc6bf66d000+22e000] > [ 377.528955] traps: systemd[5607] trap invalid opcode ip:7f791447e616 sp:7ffe83e61cf8 error:0 in libsystemd-shared-252.so[7e616,7f791446d000+22e000] > [ 377.556993] traps: systemd-coredum[12080] trap invalid opcode ip:7f97ce07f614 sp:7ffe28b56a88 error:0 in libsystemd-shared-252.so[7f614,7f97ce06d000+22e000] > [ 3746.173043] traps: hostnamectl[45846] trap invalid opcode ip:7fe00cc7f614 sp:7fff89916e48 error:0 in libsystemd-shared-252.so[7f614,7fe00cc6d000+22e000] > [ 3746.202305] traps: systemd-coredum[45847] trap invalid opcode ip:7f7fe9e7f614 sp:7ffea227cfa8 error:0 in libsystemd-shared-252.so[7f614,7f7fe9e6d000+22e000] > [ 3750.581940] traps: systemctl[45903] trap invalid opcode ip:7fbb8967f614 sp:7fff733e5748 error:0 in libsystemd-shared-252.so[7f614,7fbb8966d000+22e000] > [ 3750.612651] traps: systemd-coredum[45904] trap invalid opcode ip:7f90d347f614 sp:7ffdc7f55148 error:0 in libsystemd-shared-252.so[7f614,7f90d346d000+22e000] > > I'm not sure if this is of any use, but I collected a vmcore of > this state by intentionally crashing the host via /proc/sysrq-trigger. > > Anyway, I'll give 55780d8a1dcc some more migration rounds, but it looks > promising. 500+ migrations back and forth, no issues. I consider this solved and am rolling out the patched kernel; I’ll report if anything new turns up. Definitely a -stable candidate. Andrew, will you send it to Greg, or shall I? Thank you all for spending time on this! BR nik > > I'll report soon > > Cheers, nik > -- Ing. Nikola CIPRICH technický ředitel +420 591 166 214 +420 777 093 799 nikola.ciprich@linuxbox.cz www.linuxbox.cz