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b=f2NPtvnQXFwqudU1WmHW2/RX98/e5740Zc3kpalBsO0rznuOvLs43E/vF/dsq1Hwp x82BfDnSCbVj/UE9JJeVqP/ORgTH4WU7w19kl4iWMX8DliLjdUxoYgfSnZf4XzxGnK wbKD/gF3aC7ajt54ErRFBCKRMqk4OzUAEY+bWR3WFFEztBF4pXXmI+DdTsiuaYt9oL JnHRoSpoMuAMpr+BtDwkeWwVSZwxlNeG8JQWHNeflLf3xGo2PIVJriGbu0QBGtD7uL 8NertDYo5N3pZCYN/kwygA2m66N7wr5sBQdtAJ/3u1fWGvqAsm0i8SUdYa8J22+1SZ GKRh8BS2sOIRA== Message-ID: Date: Thu, 26 Mar 2026 13:12:03 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/damon: introduce DAMON-based NUMA memory tiering module To: "Lorenzo Stoakes (Oracle)" , Josh Law , Josh Law Cc: SeongJae Park , Andrew Morton , damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Linus Torvalds , Kees Cook , Greg KH , "David Hildenbrand (Arm)" References: <20260326072737.341964-1-objecting@objecting.org> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; keydata= xsFNBFVDQq4BEAC6KeLOfFsAvFMBsrCrJ2bCalhPv5+KQF2PS2+iwZI8BpRZoV+Bd5kWvN79 cFgcqTTuNHjAvxtUG8pQgGTHAObYs6xeYJtjUH0ZX6ndJ33FJYf5V3yXqqjcZ30FgHzJCFUu JMp7PSyMPzpUXfU12yfcRYVEMQrmplNZssmYhiTeVicuOOypWugZKVLGNm0IweVCaZ/DJDIH gNbpvVwjcKYrx85m9cBVEBUGaQP6AT7qlVCkrf50v8bofSIyVa2xmubbAwwFA1oxoOusjPIE J3iadrwpFvsZjF5uHAKS+7wHLoW9hVzOnLbX6ajk5Hf8Pb1m+VH/E8bPBNNYKkfTtypTDUCj NYcd27tjnXfG+SDs/EXNUAIRefCyvaRG7oRYF3Ec+2RgQDRnmmjCjoQNbFrJvJkFHlPeHaeS BosGY+XWKydnmsfY7SSnjAzLUGAFhLd/XDVpb1Een2XucPpKvt9ORF+48gy12FA5GduRLhQU vK4tU7ojoem/G23PcowM1CwPurC8sAVsQb9KmwTGh7rVz3ks3w/zfGBy3+WmLg++C2Wct6nM Pd8/6CBVjEWqD06/RjI2AnjIq5fSEH/BIfXXfC68nMp9BZoy3So4ZsbOlBmtAPvMYX6U8VwD TNeBxJu5Ex0Izf1NV9CzC3nNaFUYOY8KfN01X5SExAoVTr09ewARAQABzSVLcnp5c3p0b2Yg S296bG93c2tpIDxrcnprQGtlcm5lbC5vcmc+wsGVBBMBCgA/AhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgBYhBJvQfg4MUfjVlne3VBuTQ307QWKbBQJoF1BKBQkWlnSaAAoJEBuTQ307 QWKbHukP/3t4tRp/bvDnxJfmNdNVn0gv9ep3L39IntPalBFwRKytqeQkzAju0whYWg+R/rwp +r2I1Fzwt7+PTjsnMFlh1AZxGDmP5MFkzVsMnfX1lGiXhYSOMP97XL6R1QSXxaWOpGNCDaUl ajorB0lJDcC0q3xAdwzRConxYVhlgmTrRiD8oLlSCD5baEAt5Zw17UTNDnDGmZQKR0fqLpWy 786Lm5OScb7DjEgcA2PRm17st4UQ1kF0rQHokVaotxRM74PPDB8bCsunlghJl1DRK9s1aSuN hL1Pv9VD8b4dFNvCo7b4hfAANPU67W40AaaGZ3UAfmw+1MYyo4QuAZGKzaP2ukbdCD/DYnqi tJy88XqWtyb4UQWKNoQqGKzlYXdKsldYqrLHGoMvj1UN9XcRtXHST/IaLn72o7j7/h/Ac5EL 8lSUVIG4TYn59NyxxAXa07Wi6zjVL1U11fTnFmE29ALYQEXKBI3KUO1A3p4sQWzU7uRmbuxn naUmm8RbpMcOfa9JjlXCLmQ5IP7Rr5tYZUCkZz08LIfF8UMXwH7OOEX87Y++EkAB+pzKZNNd hwoXulTAgjSy+OiaLtuCys9VdXLZ3Zy314azaCU3BoWgaMV0eAW/+gprWMXQM1lrlzvwlD/k whyy9wGf0AEPpLssLVt9VVxNjo6BIkt6d1pMg6mHsUEVzsFNBFVDXDQBEADNkrQYSREUL4D3 Gws46JEoZ9HEQOKtkrwjrzlw/tCmqVzERRPvz2Xg8n7+HRCrgqnodIYoUh5WsU84N03KlLue MNsWLJBvBaubYN4JuJIdRr4dS4oyF1/fQAQPHh8Thpiz0SAZFx6iWKB7Qrz3OrGCjTPcW6ei OMheesVS5hxietSmlin+SilmIAPZHx7n242u6kdHOh+/SyLImKn/dh9RzatVpUKbv34eP1wA GldWsRxbf3WP9pFNObSzI/Bo3kA89Xx2rO2roC+Gq4LeHvo7ptzcLcrqaHUAcZ3CgFG88CnA 6z6lBZn0WyewEcPOPdcUB2Q7D/NiUY+HDiV99rAYPJztjeTrBSTnHeSBPb+qn5ZZGQwIdUW9 YegxWKvXXHTwB5eMzo/RB6vffwqcnHDoe0q7VgzRRZJwpi6aMIXLfeWZ5Wrwaw2zldFuO4Dt 91pFzBSOIpeMtfgb/Pfe/a1WJ/GgaIRIBE+NUqckM+3zJHGmVPqJP/h2Iwv6nw8U+7Yyl6gU BLHFTg2hYnLFJI4Xjg+AX1hHFVKmvl3VBHIsBv0oDcsQWXqY+NaFahT0lRPjYtrTa1v3tem/ JoFzZ4B0p27K+qQCF2R96hVvuEyjzBmdq2esyE6zIqftdo4MOJho8uctOiWbwNNq2U9pPWmu 4vXVFBYIGmpyNPYzRm0QPwARAQABwsF8BBgBCgAmAhsMFiEEm9B+DgxR+NWWd7dUG5NDfTtB YpsFAmgXUF8FCRaWWyoACgkQG5NDfTtBYptO0w//dlXJs5/42hAXKsk+PDg3wyEFb4NpyA1v qmx7SfAzk9Hf6lWwU1O6AbqNMbh6PjEwadKUk1m04S7EjdQLsj/MBSgoQtCT3MDmWUUtHZd5 RYIPnPq3WVB47GtuO6/u375tsxhtf7vt95QSYJwCB+ZUgo4T+FV4hquZ4AsRkbgavtIzQisg Dgv76tnEv3YHV8Jn9mi/Bu0FURF+5kpdMfgo1sq6RXNQ//TVf8yFgRtTUdXxW/qHjlYURrm2 H4kutobVEIxiyu6m05q3e9eZB/TaMMNVORx+1kM3j7f0rwtEYUFzY1ygQfpcMDPl7pRYoJjB dSsm0ZuzDaCwaxg2t8hqQJBzJCezTOIkjHUsWAK+tEbU4Z4SnNpCyM3fBqsgYdJxjyC/tWVT AQ18NRLtPw7tK1rdcwCl0GFQHwSwk5pDpz1NH40e6lU+NcXSeiqkDDRkHlftKPV/dV+lQXiu jWt87ecuHlpL3uuQ0ZZNWqHgZoQLXoqC2ZV5KrtKWb/jyiFX/sxSrodALf0zf+tfHv0FZWT2 zHjUqd0t4njD/UOsuIMOQn4Ig0SdivYPfZukb5cdasKJukG1NOpbW7yRNivaCnfZz6dTawXw XRIV/KDsHQiyVxKvN73bThKhONkcX2LWuD928tAR6XMM2G5ovxLe09vuOzzfTWQDsm++9UKF a/A= In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Queue-Id: 5AA684000C X-Stat-Signature: ntzsfwr3oz1s3xwcbjskwco599xw5fdx X-Rspamd-Server: rspam06 X-HE-Tag: 1774527129-781707 X-HE-Meta: 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 b239b09o Kpcf4Yy2kaTTyVk4tmDhN9RlZxHqdWHKBEcxRr9fwCkjFtTHOigE2i0wiU91EkSL8Ay3W9hlayuTTeIEjsfdnmEgrjJyoKI46UavLhhRYlCVI7vj60tilAm2uhTJcZqMAKDlwCnxDISMVRv2GtEqf4MleOjW7CGoqquHrm8Bb+41a7GxrTogpC4HJuxEeYyeCW+t8rC04s6QPwlO1ZD3sSnQXJO2Y4GUsXh197FdmRNMx3T4DPn67DxIt47MVWUEQlKOd2LWMuzmbp5mtqTcMcySz9M5yb1OJcLPLOiywFtvo/08y9pru9h3fD21V41QXwGxEEfGrobkOQKOHI8BQrArpDFEUKhoBvJe1HH/Lfb/ki2Xas7eC2o2+pinwZbnZo96nGKEMkLQ9TSooivpgzDBiSyfljw84eLk2ObXz8CSgZ+5UoilYjKDYaYaAHW779hO/ Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 26/03/2026 11:34, Lorenzo Stoakes (Oracle) wrote: Trimming context, I agree with everything said by Lorenzo, very detailed analysis. > ~~~ > ● Looking at the headers specifically: > > Infrastructure: > > - Mail provider: Zoho EU (zohomail.eu) — a privacy-oriented > EU-jurisdiction mail provider. Easy to set up anonymously. > > - Domain: objecting.org — custom domain, no organizational affiliation, > no accountability chain. Anyone can register this and point MX to Zoho. > > - Authentication: DKIM, SPF, DMARC all pass — but this only proves the > email came from objecting.org's Zoho setup, not who's behind it. > > - X-Mailer: git-send-email 2.34.1 — Ubuntu 22.04 LTS default. One reply > had @ubuntu in the Message-ID, confirming the platform. > > What the headers DON'T provide: > - No corporate or institutional email that ties to a verifiable identity > - No PGP/GPG signature > - No Signed-off-by chain from a known developer vouching for this person > > Supply chain attack assessment: > > This matches the threat model of automated supply chain compromise: > > 1. Patches already landed in stable — the bootconfig fixes made it into > 6.19.10. The pipeline is working. Whatever is in those patches is now in > production kernels. > > 2. Trust-building pattern — the mix of real bug fixes (fd leaks, > unchecked returns, type issues) alongside feature additions (DAMON > tiering module, glob features, debugfs interface) is textbook. The small > fixes build reviewer trust and merge history; the features add attack > surface. > > 3. Volume as a weapon — 328 emails in 11 days overwhelms maintainer > review capacity. Maintainers like SeongJae Park (DAMON) and Masami > Hiramatsu (bootconfig) are now spending review cycles on AI-generated > submissions. Even if every patch is rejected, the reviewer's attention is > being consumed. > > 4. The DAMON NUMA tiering module is the most concerning submission — 409 > lines of new kernel code that runs with kernel privileges, monitors > physical memory access patterns, and migrates pages between NUMA > nodes. If accepted, it's a significant new attack surface delivered as a > single commit from an unverifiable identity. > > 5. The feature additions are the real risk — bug fixes are relatively > easy to review (small, focused, verifiable). But glob_validate(), > glob_match_nocase(), the debugfs > > BUG/WARN site lister, and the DAMON tiering module all add new code paths > that are much harder to exhaustively verify. > > Bottom line: Whether the intent is malicious or not, the pattern — > anonymous identity, AI-generated code, industrial volume, patches already > in stable, mixing trust-building fixes with attack-surface-expanding > features — is exactly what an automated supply chain attack on the kernel > looks like. The 2021 University of Minnesota "Hypocrite Commits" incident > was a manual version of this; this appears to be the automated version at > scale. > > ~~~ > > I'm hoping this is some naive attempt to try to 'contribute' to the kernel > rather than something more nefarious, but the seemingly sophisticated > tooling used makes me wonder otherwise. > > In any case I'm deeply concerned by this. This patch also targets NUMA which is quite unpopular setup for hobbyist. I don't have any NUMA around me for years... Even my build machines are not NUMA. How did you get one as a hobbyist? Also after looking at the code style in this patch, after "reviews" [1] and "acks" [2] (quotes on purpose) this account gave on various patches, let's look what was admitted 3 weeks ago: https://lore.kernel.org/all/f8772114-a495-409b-a590-a9b1d8ed1d41@gmail.com/ > I'm learning this Linux system day by day So learning or adding serious code for MM for NUMA machines? > I own this device ... This is about Xilinx AXIS FIFO which is an FPGA IP core. No way you have it. It's not popular, no easy way to get it in common embedded boards. Even assuming if you have embedded FPGA device and work on it, the jump from embedded to NUMA is just stunning. Answering to reviewers with whatever confirmation they look for is also a warning sign of non-trustworthy behavior. Or rather behavior trying to get trust. [1] https://lore.kernel.org/all/D47F8215-FD08-45ED-AB01-0A5C48CD41DD@objecting.org/ [2] https://lore.kernel.org/all/2F84DD09-2880-45E0-AA98-204F10848F85@objecting.org/ Best regards, Krzysztof