From afd0a8006e98b1890908f81746c94ca5dae29d7c Mon Sep 17 00:00:00 2001 From: Jakub Audykowicz Date: Tue, 4 Dec 2018 20:27:41 +0100 Subject: sctp: frag_point sanity check If for some reason an association's fragmentation point is zero, sctp_datamsg_from_user will try to endlessly try to divide a message into zero-sized chunks. This eventually causes kernel panic due to running out of memory. Although this situation is quite unlikely, it has occurred before as reported. I propose to add this simple last-ditch sanity check due to the severity of the potential consequences. Signed-off-by: Jakub Audykowicz Acked-by: Neil Horman Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- include/net/sctp/sctp.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/net/sctp') diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index ab9242e51d9e..2abbc15824af 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -620,4 +620,9 @@ static inline bool sctp_transport_pmtu_check(struct sctp_transport *t) return false; } +static inline __u32 sctp_min_frag_point(struct sctp_sock *sp, __u16 datasize) +{ + return sctp_mtu_payload(sp, SCTP_DEFAULT_MINSEGMENT, datasize); +} + #endif /* __net_sctp_h__ */ -- cgit v1.2.3-73-gaa49b