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| author | Michael Tuexen <tuexen@FreeBSD.org> | 2021-04-26 08:38:05 +0000 |
|---|---|---|
| committer | Michael Tuexen <tuexen@FreeBSD.org> | 2021-04-26 08:43:58 +0000 |
| commit | c70d1ef15db0d994eff4a2c4d9feabdc46bff1c6 (patch) | |
| tree | 666f6a2342cbd862876384c320e247d264ecdaa1 | |
| parent | 9f1dc86c46d69d31a819fa150ce1d91fb987a61b (diff) | |
| download | src-c70d1ef15db0d994eff4a2c4d9feabdc46bff1c6.tar.gz src-c70d1ef15db0d994eff4a2c4d9feabdc46bff1c6.zip | |
sctp: improve handling of illegal packets containing INIT chunks
Stop further processing of a packet when detecting that it
contains an INIT chunk, which is too small or is not the only
chunk in the packet. Still allow to finish the processing
of chunks before the INIT chunk.
Thanks to Antoly Korniltsev and Taylor Brandstetter for reporting
an issue with the userland stack, which made me aware of this
issue.
MFC after: 3 days
| -rw-r--r-- | sys/netinet/sctp_input.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/sys/netinet/sctp_input.c b/sys/netinet/sctp_input.c index 5b4c3152da0d..c70358f0af07 100644 --- a/sys/netinet/sctp_input.c +++ b/sys/netinet/sctp_input.c @@ -4611,10 +4611,7 @@ process_control_chunks: chunk_buf); if (ch == NULL) { *offset = length; - if (stcb != NULL) { - SCTP_TCB_UNLOCK(stcb); - } - return (NULL); + return (stcb); } num_chunks++; @@ -4648,12 +4645,12 @@ process_control_chunks: /* The INIT chunk must be the only chunk. */ if ((num_chunks > 1) || (length - *offset > (int)SCTP_SIZE32(chk_length))) { - /* RFC 4960 requires that no ABORT is sent */ + /* + * RFC 4960bis requires stopping the + * processing of the packet. + */ *offset = length; - if (stcb != NULL) { - SCTP_TCB_UNLOCK(stcb); - } - return (NULL); + return (stcb); } /* Honor our resource limit. */ if (chk_length > SCTP_LARGEST_INIT_ACCEPTED) { |