tcp: sysctl interface leaks 16 bytes of kernel memory

If the rc_dereference of tcp_fastopen_ctx ever fails then we copy 16 bytes
of kernel stack into the proc result.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alan Cox 2012-10-11 06:24:14 +00:00 committed by David S. Miller
parent 0abc1ceec5
commit 0e24c4fc52

View File

@ -248,6 +248,8 @@ int proc_tcp_fastopen_key(ctl_table *ctl, int write, void __user *buffer,
ctxt = rcu_dereference(tcp_fastopen_ctx);
if (ctxt)
memcpy(user_key, ctxt->key, TCP_FASTOPEN_KEY_LENGTH);
else
memset(user_key, 0, sizeof(user_key));
rcu_read_unlock();
snprintf(tbl.data, tbl.maxlen, "%08x-%08x-%08x-%08x",