From: Matthew Wilcox <willy@infradead.org>
To: linux-fsdevel@vger.kernel.org, David Howells <dhowells@redhat.com>
Subject: [PATCH] ramfs: Fix nommu mmap with gaps in the page cache
Date: Mon, 14 Sep 2020 13:22:39 +0100 [thread overview]
Message-ID: <20200914122239.GO6583@casper.infradead.org> (raw)
From: Matthew Wilcox (Oracle) <willy@infradead.org>
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) <willy@infradead.org>
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index 414695454956..355523f4a4bf 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 */
reply other threads:[~2020-09-14 17:39 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200914122239.GO6583@casper.infradead.org \
--to=willy@infradead.org \
--cc=dhowells@redhat.com \
--cc=linux-fsdevel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).