[maverick, maverick/ti-omap4, natty, natty/ti-omap4 CVE 1/1] fuse: check size of FUSE_NOTIFY_INVAL_ENTRY message

[Andy Whitcroft]

From: Miklos Szeredi <mszeredi at suse.cz>

FUSE_NOTIFY_INVAL_ENTRY didn't check the length of the write so the
message processing could overrun and result in a "kernel BUG at
fs/fuse/dev.c:629!"

Reported-by: Han-Wen Nienhuys <hanwenn at gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi at suse.cz>
CC: stable at kernel.org

(cherry picked from commit c2183d1e9b3f313dd8ba2b1b0197c8d9fb86a7ae)
CVE-2011-3353
BugLink: http://bugs.launchpad.net/bugs/905058
Signed-off-by: Andy Whitcroft <apw at canonical.com>
---
 fs/fuse/dev.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index e5cdabf..517430a 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1208,6 +1208,10 @@ static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
 	if (outarg.namelen > FUSE_NAME_MAX)
 		goto err;
 
+	err = -EINVAL;
+	if (size != sizeof(outarg) + outarg.namelen + 1)
+		goto err;
+
 	name.name = buf;
 	name.len = outarg.namelen;
 	err = fuse_copy_one(cs, buf, outarg.namelen + 1);
-- 
1.7.5.4