4.19-stable review patch. If anyone has any objections, please let me know.
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From: Xin Long lucien.xin@gmail.com
[ Upstream commit 4135cce7fd0a0d755665c02728578c7c5afe4726 ]
sctp_assoc_update_frag_point() should be called whenever asoc->pathmtu changes, but we missed one place in sctp_association_init(). It would cause frag_point is zero when sending data.
As says in Jakub's reproducer, if sp->pathmtu is set by socketopt, the new asoc->pathmtu inherits it in sctp_association_init(). Later when transports are added and their pmtu >= asoc->pathmtu, it will never call sctp_assoc_update_frag_point() to set frag_point.
This patch is to fix it by updating frag_point after asoc->pathmtu is set as sp->pathmtu in sctp_association_init(). Note that it moved them after sctp_stream_init(), as stream->si needs to be set first.
Frag_point's calculation is also related with datachunk's type, so it needs to update frag_point when stream->si may be changed in sctp_process_init().
v1->v2: - call sctp_assoc_update_frag_point() separately in sctp_process_init and sctp_association_init, per Marcelo's suggestion.
Fixes: 2f5e3c9df693 ("sctp: introduce sctp_assoc_update_frag_point") Reported-by: Jakub Audykowicz jakub.audykowicz@gmail.com Signed-off-by: Xin Long lucien.xin@gmail.com Acked-by: Marcelo Ricardo Leitner marcelo.leitner@gmail.com Acked-by: Neil Horman nhorman@tuxdriver.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sctp/associola.c | 7 ++++--- net/sctp/sm_make_chunk.c | 3 +++ 2 files changed, 7 insertions(+), 3 deletions(-)
--- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -118,9 +118,6 @@ static struct sctp_association *sctp_ass asoc->flowlabel = sp->flowlabel; asoc->dscp = sp->dscp;
- /* Initialize default path MTU. */ - asoc->pathmtu = sp->pathmtu; - /* Set association default SACK delay */ asoc->sackdelay = msecs_to_jiffies(sp->sackdelay); asoc->sackfreq = sp->sackfreq; @@ -252,6 +249,10 @@ static struct sctp_association *sctp_ass 0, gfp)) goto fail_init;
+ /* Initialize default path MTU. */ + asoc->pathmtu = sp->pathmtu; + sctp_assoc_update_frag_point(asoc); + /* Assume that peer would support both address types unless we are * told otherwise. */ --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -2462,6 +2462,9 @@ int sctp_process_init(struct sctp_associ asoc->c.sinit_max_instreams, gfp)) goto clean_up;
+ /* Update frag_point when stream_interleave may get changed. */ + sctp_assoc_update_frag_point(asoc); + if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) goto clean_up;