[PATCH] sctp: socket.c validate sprstat_policy
From: Tomas Bortoli <hidden>
Date: 2018-10-27 19:59:09
Also in:
linux-sctp, lkml
Subsystem:
networking [general], sctp protocol, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Marcelo Ricardo Leitner, Xin Long, Linus Torvalds
It is possible to perform out-of-bound reads on sctp_getsockopt_pr_streamstatus() and on sctp_getsockopt_pr_assocstatus() by passing from userspace a sprstat_policy that overflows the abandoned_sent/abandoned_unsent fixed length arrays. The over-read data are directly copied/leaked to userspace. Signed-off-by: Tomas Bortoli <redacted> Reported-by: syzbot+5da0d0a72a9e7d791748@syzkaller.appspotmail.com --- net/sctp/socket.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index fc0386e8ff23..5290b8bd40c8 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c@@ -7083,7 +7083,8 @@ static int sctp_getsockopt_pr_assocstatus(struct sock *sk, int len, } policy = params.sprstat_policy; - if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL))) + if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) + __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX)) goto out; asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
@@ -7142,7 +7143,8 @@ static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len, } policy = params.sprstat_policy; - if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL))) + if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) || + __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX)) goto out; asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
--
2.11.0