linux-kernel - [03/49] fuse: verify ioctl retries

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 05 Jan 2011 15:00:21 -0800
From:	Greg KH <gregkh@...e.de>
To:	linux-kernel@...r.kernel.org, stable@...nel.org
Cc:	stable-review@...nel.org, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org, alan@...rguk.ukuu.org.uk,
	Miklos Szeredi <mszeredi@...e.cz>, Tejun Heo <tj@...nel.org>
Subject: [03/49] fuse: verify ioctl retries

2.6.32-longterm review patch.  If anyone has any objections, please let us know.

------------------

From: Miklos Szeredi <mszeredi@...e.cz>

commit 7572777eef78ebdee1ecb7c258c0ef94d35bad16 upstream.

Verify that the total length of the iovec returned in FUSE_IOCTL_RETRY
doesn't overflow iov_length().

Signed-off-by: Miklos Szeredi <mszeredi@...e.cz>
CC: Tejun Heo <tj@...nel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>

---
 fs/fuse/file.c |   22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1619,6 +1619,20 @@ static int fuse_ioctl_copy_user(struct p
 	return 0;
 }
 
+/* Make sure iov_length() won't overflow */
+static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count)
+{
+	size_t n;
+	u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT;
+
+	for (n = 0; n < count; n++) {
+		if (iov->iov_len > (size_t) max)
+			return -ENOMEM;
+		max -= iov->iov_len;
+	}
+	return 0;
+}
+
 /*
  * For ioctls, there is no generic way to determine how much memory
  * needs to be read and/or written.  Furthermore, ioctls are allowed
@@ -1812,6 +1826,14 @@ long fuse_do_ioctl(struct file *file, un
 		in_iov = page_address(iov_page);
 		out_iov = in_iov + in_iovs;
 
+		err = fuse_verify_ioctl_iov(in_iov, in_iovs);
+		if (err)
+			goto out;
+
+		err = fuse_verify_ioctl_iov(out_iov, out_iovs);
+		if (err)
+			goto out;
+
 		goto retry;
 	}
 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/