From: Sasha Levin
Sent: 03 February 2018 18:01 [ Upstream commit 5c468674d17056148da06218d4da5d04baf22eac ]
Now when reneging events in sctp_ulpq_renege(), the variable freed could be increased by a __u16 value twice while freed is of __u16 type. It means freed may overflow at the second addition.
This patch is to fix it by using __u32 type for 'freed', while at it, also to remove 'if (chunk)' check, as all renege commands are generated in sctp_eat_data and it can't be NULL.
Reported-by: Marcelo Ricardo Leitner marcelo.leitner@gmail.com Signed-off-by: Xin Long lucien.xin@gmail.com Acked-by: Neil Horman nhorman@tuxdriver.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com
net/sctp/ulpqueue.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-)
diff --git a/net/sctp/ulpqueue.c b/net/sctp/ulpqueue.c index a71be33f3afe..e36ec5dd64c6 100644 --- a/net/sctp/ulpqueue.c +++ b/net/sctp/ulpqueue.c @@ -1084,29 +1084,21 @@ void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq, void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, gfp_t gfp) {
- struct sctp_association *asoc;
- __u16 needed, freed;
- asoc = ulpq->asoc;
- struct sctp_association *asoc = ulpq->asoc;
- __u32 freed = 0;
- __u16 needed;
- if (chunk) {
needed = ntohs(chunk->chunk_hdr->length);needed -= sizeof(struct sctp_data_chunk);- } else
needed = SCTP_DEFAULT_MAXWINDOW;- freed = 0;
needed = ntohs(chunk->chunk_hdr->length) -
sizeof(struct sctp_data_chunk);if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) { freed = sctp_ulpq_renege_order(ulpq, needed);
if (freed < needed) {
if (freed < needed) freed += sctp_ulpq_renege_frags(ulpq, needed - freed);
}- if (chunk && (freed >= needed)) {
int retval;retval = sctp_ulpq_tail_data(ulpq, chunk, gfp);
- if (freed >= needed) {
int retval = sctp_ulpq_tail_data(ulpq, chunk, gfp);
- Enter partial delivery if chunk has not been
- delivered; otherwise, drain the reassembly queue.
Hmmm... ISTM that all the maths should be done using 'unsigned int' to avoid horrid masking operations on many cpus....
David