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

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: 3c68198e7 ("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>
This commit is contained in:
Sasha Levin 2016-01-07 14:52:43 -05:00 committed by David S. Miller
parent 18715b2615
commit 320f1a4a17

View File

@ -320,7 +320,7 @@ 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));