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authorXin Long <lucien.xin@gmail.com>2019-02-12 18:51:01 +0800
committerDavid S. Miller <davem@davemloft.net>2019-02-13 19:33:44 -0500
commitaf98c5a78517c04adb5fd68bb64b1ad6fe3d473f (patch)
parentfc228abc2347e106a44c0e9b29ab70b712c4ca51 (diff)
sctp: set stream ext to NULL after freeing it in sctp_stream_outq_migrate
In sctp_stream_init(), after sctp_stream_outq_migrate() freed the surplus streams' ext, but sctp_stream_alloc_out() returns -ENOMEM, stream->outcnt will not be set to 'outcnt'. With the bigger value on stream->outcnt, when closing the assoc and freeing its streams, the ext of those surplus streams will be freed again since those stream exts were not set to NULL after freeing in sctp_stream_outq_migrate(). Then the invalid-free issue reported by syzbot would be triggered. We fix it by simply setting them to NULL after freeing. Fixes: 5bbbbe32a431 ("sctp: introduce stream scheduler foundations") Reported-by: syzbot+58e480e7b28f2d890bfd@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 files changed, 3 insertions, 1 deletions
diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index f24633114dfd..2936ed17bf9e 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -144,8 +144,10 @@ static void sctp_stream_outq_migrate(struct sctp_stream *stream,
- for (i = outcnt; i < stream->outcnt; i++)
+ for (i = outcnt; i < stream->outcnt; i++) {
kfree(SCTP_SO(stream, i)->ext);
+ SCTP_SO(stream, i)->ext = NULL;
+ }
static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,