fuse: reject internal errno

BugLink: https://bugs.launchpad.net/bugs/1938199
commit 49221cf86d18bb66fe95d3338cb33bd4b9880ca5 upstream.

Don't allow userspace to report errors that could be kernel-internal.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Fixes: 334f485df85a ("[PATCH] FUSE - device functions")
Cc: <stable@vger.kernel.org> # v2.6.14
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index d6f8075f3950b8693ba5240c64a040b4bad33cff..16aa55b73ccf5eebc7576ebff760d3c6fe823535 100644 (file)
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1869,7 +1869,7 @@ static ssize_t fuse_dev_do_write(struct fuse_dev *fud,
        }
 
        err = -EINVAL;
-       if (oh.error <= -1000 || oh.error > 0)
+       if (oh.error <= -512 || oh.error > 0)
                goto copy_finish;
 
        spin_lock(&fpq->lock);