Commit ea06dfa2 authored Jan 07, 2016 by Sasha Levin

net: sctp: prevent writes to cookie_hmac_alg from accessing invalid memory



[ Upstream commit 320f1a4a175e7cd5d3f006f92b4d4d3e2cbb7bb5 ]

proc_dostring() needs an initialized destination string, while the one
provided in proc_sctp_do_hmac_alg() contains stack garbage.

Thus, writing to cookie_hmac_alg would strlen() that garbage and end up
accessing invalid memory.

Fixes: 3c68198e ("sctp: Make hmac algorithm selection for cookie generation dynamic")
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

parent d2f500d1

net/sctp/sysctl.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -324,7 +324,7 @@ static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
		struct ctl_table tbl;
		bool changed = false;
		char *none = "none";
		char tmp[8];
		char tmp[8] = {0};
		int ret;

		memset(&tbl, 0, sizeof(struct ctl_table));