From: NeilBrown <neilb@suse.de> commit af8085f3a4712c57d0dd415ad543bac85780375c upstream. The sctp transport seq_file iterators take a reference to the transport in the ->start and ->next functions and releases the reference in the ->show function. The preferred handling for such resources is to release them in the subsequent ->next or ->stop function call. Since Commit 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface") there is no guarantee that ->show will be called after ->next, so this function can now leak references. So move the sctp_transport_put() call to ->next and ->stop. Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface") Reported-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/sctp/proc.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/net/sctp/proc.c b/net/sctp/proc.c index a644292f9fafd..84f79ac4b9842 100644 --- a/net/sctp/proc.c +++ b/net/sctp/proc.c @@ -230,6 +230,12 @@ static void sctp_transport_seq_stop(struct seq_file *seq, void *v) { struct sctp_ht_iter *iter = seq->private; + if (v && v != SEQ_START_TOKEN) { + struct sctp_transport *transport = v; + + sctp_transport_put(transport); + } + sctp_transport_walk_stop(&iter->hti); } @@ -237,6 +243,12 @@ static void *sctp_transport_seq_next(struct seq_file *seq, void *v, loff_t *pos) { struct sctp_ht_iter *iter = seq->private; + if (v && v != SEQ_START_TOKEN) { + struct sctp_transport *transport = v; + + sctp_transport_put(transport); + } + ++*pos; return sctp_transport_get_next(seq_file_net(seq), &iter->hti); @@ -292,8 +304,6 @@ static int sctp_assocs_seq_show(struct seq_file *seq, void *v) sk->sk_rcvbuf); seq_printf(seq, "\n"); - sctp_transport_put(transport); - return 0; } @@ -369,8 +379,6 @@ static int sctp_remaddr_seq_show(struct seq_file *seq, void *v) seq_printf(seq, "\n"); } - sctp_transport_put(transport); - return 0; } -- 2.25.1