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authorDaniel Borkmann <dborkman@redhat.com>2014-06-18 23:46:31 +0200
committerDavid S. Miller <davem@davemloft.net>2014-06-19 21:30:19 -0700
commit24599e61b7552673dd85971cf5a35369cd8c119e (patch)
tree969fd9c03baf1de6f39cd7057adf78eace68936d
parent40c1deaf6c2b42d7ee4e604ba5793cf9da292d96 (diff)
net: sctp: check proc_dointvec result in proc_sctp_do_auth
When writing to the sysctl field net.sctp.auth_enable, it can well be that the user buffer we handed over to proc_dointvec() via proc_sctp_do_auth() handler contains something other than integers. In that case, we would set an uninitialized 4-byte value from the stack to net->sctp.auth_enable that can be leaked back when reading the sysctl variable, and it can unintentionally turn auth_enable on/off based on the stack content since auth_enable is interpreted as a boolean. Fix it up by making sure proc_dointvec() returned sucessfully. Fixes: b14878ccb7fa ("net: sctp: cache auth_enable per endpoint") Reported-by: Florian Westphal <fwestpha@redhat.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/sctp/sysctl.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index cc12162ba091..12c7e01c2677 100644
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -447,8 +447,7 @@ static int proc_sctp_do_auth(struct ctl_table *ctl, int write,
tbl.data = &net->sctp.auth_enable;
ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
-
- if (write) {
+ if (write && ret == 0) {
struct sock *sk = net->sctp.ctl_sock;
net->sctp.auth_enable = new_value;