From: Matthew Wilcox (Oracle) Date: Fri, 16 Oct 2020 03:13:04 +0000 (-0700) Subject: ramfs: fix nommu mmap with gaps in the page cache X-Git-Tag: v5.10.7~1400^2~13 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=50b7d85680086126d7bd91dae81d57d4cb1ab6b7;p=platform%2Fkernel%2Flinux-rpi.git ramfs: fix nommu mmap with gaps in the page cache ramfs needs to check that pages are both physically contiguous and contiguous in the file. If the page cache happens to have, eg, page A for index 0 of the file, no page for index 1, and page A+1 for index 2, then an mmap of the first two pages of the file will succeed when it should fail. Fixes: 642fb4d1f1dd ("[PATCH] NOMMU: Provide shared-writable mmap support on ramfs") Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton Cc: David Howells Link: https://lkml.kernel.org/r/20200914122239.GO6583@casper.infradead.org Signed-off-by: Linus Torvalds --- diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c index 4146954..355523f 100644 --- a/fs/ramfs/file-nommu.c +++ b/fs/ramfs/file-nommu.c @@ -224,7 +224,7 @@ static unsigned long ramfs_nommu_get_unmapped_area(struct file *file, if (!pages) goto out_free; - nr = find_get_pages(inode->i_mapping, &pgoff, lpages, pages); + nr = find_get_pages_contig(inode->i_mapping, pgoff, lpages, pages); if (nr != lpages) goto out_free_pages; /* leave if some pages were missing */