From: Miklos Szeredi mszeredi@redhat.com
stable inclusion from linux-4.19.191 commit 2bb2ff46d21d6794fd298df177199a2bb3b98434
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[ Upstream commit 8217673d07256b22881127bf50dce874d0e51653 ]
For cloned connections cuse_channel_release() will be called more than once, resulting in use after free.
Prevent device cloning for CUSE, which does not make sense at this point, and highly unlikely to be used in real life.
Signed-off-by: Miklos Szeredi mszeredi@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- fs/fuse/cuse.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c index f057c213c453a..e10e2b62ccf45 100644 --- a/fs/fuse/cuse.c +++ b/fs/fuse/cuse.c @@ -621,6 +621,8 @@ static int __init cuse_init(void) cuse_channel_fops.owner = THIS_MODULE; cuse_channel_fops.open = cuse_channel_open; cuse_channel_fops.release = cuse_channel_release; + /* CUSE is not prepared for FUSE_DEV_IOC_CLONE */ + cuse_channel_fops.unlocked_ioctl = NULL;
cuse_class = class_create(THIS_MODULE, "cuse"); if (IS_ERR(cuse_class))