linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Kirill Tkhai <ktkhai@virtuozzo.com>
To: miklos@szeredi.hu, dvyukov@google.com,
	syzbot+4e975615ca01f2277bdd@syzkaller.appspotmail.com,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	ktkhai@virtuozzo.com
Subject: [PATCH] fuse: Fix use-after-free in fuse_dev_do_write()
Date: Tue, 25 Sep 2018 12:52:42 +0300	[thread overview]
Message-ID: <153786915356.22029.14929917223689579717.stgit@localhost.localdomain> (raw)

After we found req in request_find() and released the lock,
everything may happen with the req in parallel.

Keep it alive till we finish touch its memory.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
---
 fs/fuse/dev.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 675caed3e655..c2af8042f176 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1877,16 +1877,20 @@ static ssize_t fuse_dev_do_write(struct fuse_dev *fud,
 
 	/* Is it an interrupt reply? */
 	if (req->intr_unique == oh.unique) {
+		__fuse_get_request(req);
 		spin_unlock(&fpq->lock);
 
 		err = -EINVAL;
-		if (nbytes != sizeof(struct fuse_out_header))
+		if (nbytes != sizeof(struct fuse_out_header)) {
+			fuse_put_request(fc, req);
 			goto err_finish;
+		}
 
 		if (oh.error == -ENOSYS)
 			fc->no_interrupt = 1;
 		else if (oh.error == -EAGAIN)
 			queue_interrupt(&fc->iq, req);
+		fuse_put_request(fc, req);
 
 		fuse_copy_finish(cs);
 		return nbytes;

             reply	other threads:[~2018-09-25 15:59 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-25  9:52 Kirill Tkhai [this message]
2018-10-01  9:26 ` 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=153786915356.22029.14929917223689579717.stgit@localhost.localdomain \
    --to=ktkhai@virtuozzo.com \
    --cc=dvyukov@google.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=miklos@szeredi.hu \
    --cc=syzbot+4e975615ca01f2277bdd@syzkaller.appspotmail.com \
    --subject='Re: [PATCH] fuse: Fix use-after-free in fuse_dev_do_write()' \
    /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

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).