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>

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>
Sasha Levin · David S. Miller
1 parent 18715b2615
Showing 1 changed file with 1 additions and 1 deletions Side-by-side Diff
net/sctp/sysctl.c
@@ -320,7 +320,7 @@
 	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));
...	...	@@ -320,7 +320,7 @@
320	320	struct ctl_table tbl;
321	321	bool changed = false;
322	322	char *none = "none";
323		- char tmp[8];
	323	+ char tmp[8] = {0};
324	324	int ret;
325	325
326	326	memset(&tbl, 0, sizeof(struct ctl_table));