From: Elena Reshetova <elena.reshetova@intel.com>
To: linux-kernel@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org, peterz@infradead.org,
gregkh@linuxfoundation.org, miklos@szeredi.hu,
Elena Reshetova <elena.reshetova@intel.com>,
Hans Liljestrand <ishkamiel@gmail.com>,
Kees Cook <keescook@chromium.org>,
David Windsor <dwindsor@gmail.com>
Subject: [PATCH 2/3] fs, fuse: convert fuse_req.count from atomic_t to refcount_t
Date: Fri, 3 Mar 2017 11:04:04 +0200 [thread overview]
Message-ID: <1488531845-23463-3-git-send-email-elena.reshetova@intel.com> (raw)
In-Reply-To: <1488531845-23463-1-git-send-email-elena.reshetova@intel.com>
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
---
fs/fuse/dev.c | 10 +++++-----
fs/fuse/fuse_i.h | 2 +-
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index f117926..3e67205 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -44,7 +44,7 @@ static void fuse_request_init(struct fuse_req *req, struct page **pages,
INIT_LIST_HEAD(&req->list);
INIT_LIST_HEAD(&req->intr_entry);
init_waitqueue_head(&req->waitq);
- atomic_set(&req->count, 1);
+ refcount_set(&req->count, 1);
req->pages = pages;
req->page_descs = page_descs;
req->max_pages = npages;
@@ -101,14 +101,14 @@ void fuse_request_free(struct fuse_req *req)
void __fuse_get_request(struct fuse_req *req)
{
- atomic_inc(&req->count);
+ refcount_inc(&req->count);
}
/* Must be called with > 1 refcount */
static void __fuse_put_request(struct fuse_req *req)
{
- BUG_ON(atomic_read(&req->count) < 2);
- atomic_dec(&req->count);
+ BUG_ON(refcount_read(&req->count) < 2);
+ refcount_dec(&req->count);
}
static void fuse_req_init_context(struct fuse_req *req)
@@ -263,7 +263,7 @@ struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
{
- if (atomic_dec_and_test(&req->count)) {
+ if (refcount_dec_and_test(&req->count)) {
if (test_bit(FR_BACKGROUND, &req->flags)) {
/*
* We get here in the unlikely case that a background
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 1d6d67e..9d43740 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -307,7 +307,7 @@ struct fuse_req {
struct list_head intr_entry;
/** refcount */
- atomic_t count;
+ refcount_t count;
/** Unique ID for the interrupt request */
u64 intr_unique;
--
2.7.4
next prev parent reply other threads:[~2017-03-03 9:07 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-03 9:04 [PATCH 0/3] fs, fuse subsystem refcount conversions Elena Reshetova
2017-03-03 9:04 ` [PATCH 1/3] fs, fuse: convert fuse_file.count from atomic_t to refcount_t Elena Reshetova
2017-03-03 9:04 ` Elena Reshetova [this message]
2017-03-03 9:04 ` [PATCH 3/3] fs, fuse: convert fuse_conn.count " Elena Reshetova
2017-03-03 16:05 ` [PATCH 0/3] fs, fuse subsystem refcount conversions Miklos Szeredi
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=1488531845-23463-3-git-send-email-elena.reshetova@intel.com \
--to=elena.reshetova@intel.com \
--cc=dwindsor@gmail.com \
--cc=gregkh@linuxfoundation.org \
--cc=ishkamiel@gmail.com \
--cc=keescook@chromium.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=miklos@szeredi.hu \
--cc=peterz@infradead.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).