[ Upstream commit 06ebb06d49 ]
Check for cases when the caller requests 0 bytes instead of running off
and dereferencing potentially invalid iovecs.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>