Commit 0e24c4fc authored Oct 11, 2012 by Alan Cox Committed by David S. Miller Oct 11, 2012

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>

parent 0abc1cee

net/ipv4/sysctl_net_ipv4.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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",

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