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x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 1BF3940007 X-Rspam-User: X-Stat-Signature: r4du5549bc55iniyb1oys5jq5t1jqbi1 X-HE-Tag: 1782353063-181306 X-HE-Meta: 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 l35KRtJY GeaCJ9Qe8BKxBVlamnHpLFzkzgJecsuGEZhLB1SN1bxfq/goGf6jbgNsGLOAkIOgl16hxzJRmxqZaLjqxLn412QKGwmOzwZnwlTr079fZr200q3q1rDfkAjLn5PRudRjpMYkw6Xm2mnRPLRDbk80ZWgP9eUWpp2Q8nOPf6niTtpyrwsUow/jd2tpVnPbcJQAhey1ZKaG8p5t+12+OZZ1IAiV9NQHQ9j9287XOmr0CAznnibCAzOee0oXI3lf48TC6ixiAmX/cybEW094+Z8+6VMNkcK3WbbrKjUM2VwGwbuj7D7dNSkl3OJhogl+rVGArn7DH7mtfQeUkyR3bjNBLXGqIXdTnz6N2+eg7na6NQMB2M3G+WLpP/cBeHa7VG8We2uhbyDZ2UoiqxvytRiTfElQVvQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, 25 Jun 2026 09:47:03 +0800 Ye Liu wrote: > Fix two TOCTOU races found during review of [1]. > > page_owner reads page state locklessly by design. In two places the > code reads the same metadata twice — once as a guard, then again as > a use — and the page can be concurrently reallocated between the two: > > Patch 1: buddy_order_unsafe() in skip_buddy_pages() can return garbage > if the page is allocated between PageBuddy() and the private read, > causing the PFN to skip past a pfn_valid() boundary. Clamp the > advance at MAX_ORDER_NR_PAGES. > > Patch 2: PageMemcgKmem() in print_page_owner_memcg() re-reads > folio->memcg_data and triggers VM_BUG_ON assertions if the page > became a tail page or slab page. Use the snapshot taken at entry. That was fast. I haven't pushed out mm-new yet, so Sashiko wasn't able to apply these. > [1] https://lore.kernel.org/all/20260623065234.31866-2-ye.liu@linux.dev/ > [2] https://sashiko.dev/#/patchset/20260623065234.31866-2-ye.liu@linux.dev Nothing cites "[2]". That's OK.