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charset=UTF-8 Date: Wed, 25 Feb 2026 17:26:28 +0800 Mime-Version: 1.0 X-Stat-Signature: kqga5rwqwd57j3r1zaqf1ciw8y7pqugg X-Rspam-User: X-Rspamd-Queue-Id: 0BF734000F X-Rspamd-Server: rspam01 X-HE-Tag: 1772011676-880216 X-HE-Meta: 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 FyEjzwWx HVEdI49zd46akMfk66TSobQVqWwDxXy6UCvKeGTwVrfxwHr0WOKTcQOVWai74fJtnlSIyPnUzFR7adOB91RhS+rf14Lm+WTDOuAR/jSqHdLQASZgV7ZiylHNOCTZ0RfRgGRf9a20ArNng2PHJ1kEwdiZRJKxmCOwN7b/NS73HRG8CGA5KGiCAf0VxNpavKGh4Dk7VLdh7gaM/zsqLqghlONXvMucKikdI71qzPhDVA1Ft/fuoPbXvSO1GXAm4cz2AwKsqMSj3giCOlk8FFxXhl8uJ/o/xAndGIG362TIMqEWST6s= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: In folio_zero_user(), the page pointer is calculated via folio_page() before checking if the number of pages to be cleared is greater than zero. Furthermore, folio_page() does not verify that the page number lies within folio. When 'addr_hint' is near the end of a large folio, the range 'r[0]' represents an empty interval. In this scenario, 'nr_pages' will be calculated as 0 and 'r[0].start' can be an index that is out-of-bounds for folio_page(). The code unconditionally calls folio_page() on a wrong index, even though the subsequent clearing logic is correctly skipped. While this does not cause a functional bug today, calculating a page pointer for an out-of-bounds index is logically unsound and fragile. It could pose a risk for future refactoring or trigger warnings from static analysis tools. To fix this, move the call to folio_page() inside the 'if (nr_pages > 0)' block. This ensures that the page pointer is only calculated when it is actually needed for a valid, non-empty range of pages, thus making the code more robust and logically correct. Signed-off-by: Li Zhe --- mm/memory.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 07778814b4a8..6f8c55d604b5 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -7343,12 +7343,14 @@ void folio_zero_user(struct folio *folio, unsigned long addr_hint) r[0] = DEFINE_RANGE(r[2].end + 1, pg.end); for (i = 0; i < ARRAY_SIZE(r); i++) { - const unsigned long addr = base_addr + r[i].start * PAGE_SIZE; const long nr_pages = (long)range_len(&r[i]); - struct page *page = folio_page(folio, r[i].start); - if (nr_pages > 0) + if (nr_pages > 0) { + const unsigned long addr = base_addr + r[i].start * PAGE_SIZE; + struct page *page = folio_page(folio, r[i].start); + clear_contig_highpages(page, addr, nr_pages); + } } } -- 2.20.1