From: "zhangyi (F)" <yi.zhang@huawei.com>
To: <linux-fsdevel@vger.kernel.org>
Cc: <mawilcox@microsoft.com>, <ross.zwisler@linux.intel.com>,
<viro@zeniv.linux.org.uk>, <yi.zhang@huawei.com>,
<miaoxie@huawei.com>
Subject: [PATCH] dax: fix potential overflow on 32bit machine
Date: Tue, 5 Dec 2017 11:32:10 +0800 [thread overview]
Message-ID: <20171205033210.38338-1-yi.zhang@huawei.com> (raw)
On 32bit machine, when mmap2 a large enough file with pgoff more than
ULONG_MAX >> PAGE_SHIFT, it will trigger offset overflow and lead to
unmap the wrong page in dax_insert_mapping_entry(). This patch cast
pgoff to 64bit to prevent the overflow.
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
---
fs/dax.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 78b72c4..8e12848 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -539,10 +539,11 @@ static void *dax_insert_mapping_entry(struct address_space *mapping,
/* we are replacing a zero page with block mapping */
if (dax_is_pmd_entry(entry))
unmap_mapping_range(mapping,
- (vmf->pgoff << PAGE_SHIFT) & PMD_MASK,
+ ((loff_t)vmf->pgoff << PAGE_SHIFT) & PMD_MASK,
PMD_SIZE, 0);
else /* pte entry */
- unmap_mapping_range(mapping, vmf->pgoff << PAGE_SHIFT,
+ unmap_mapping_range(mapping,
+ (loff_t)vmf->pgoff << PAGE_SHIFT,
PAGE_SIZE, 0);
}
--
2.9.5
next reply other threads:[~2017-12-05 3:26 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-05 3:32 zhangyi (F) [this message]
2017-12-05 5:24 ` [PATCH] dax: fix potential overflow on 32bit machine Matthew Wilcox
2017-12-05 5:24 ` Matthew Wilcox
2017-12-05 8:40 ` zhangyi (F)
2017-12-05 8:40 ` zhangyi (F)
2017-12-05 17:07 ` Ross Zwisler
2017-12-05 17:37 ` Matthew Wilcox
2017-12-05 19:19 ` Ross Zwisler
2017-12-05 19:54 ` Matthew Wilcox
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=20171205033210.38338-1-yi.zhang@huawei.com \
--to=yi.zhang@huawei.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=mawilcox@microsoft.com \
--cc=miaoxie@huawei.com \
--cc=ross.zwisler@linux.intel.com \
--cc=viro@zeniv.linux.org.uk \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.