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author | Xin Long <lucien.xin@gmail.com> | 2017-07-26 16:24:59 +0800 |
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committer | David S. Miller <davem@davemloft.net> | 2017-07-27 00:03:12 -0700 |
commit | 6b84202c946cd3da3a8daa92c682510e9ed80321 (patch) | |
tree | 017fb69be1e7083df03315af8a40b5c42709ff0b /include/net | |
parent | e90ce2fc27cad7e7b1e72b9e66201a7a4c124c2b (diff) | |
download | linux-6b84202c946cd3da3a8daa92c682510e9ed80321.tar.gz linux-6b84202c946cd3da3a8daa92c682510e9ed80321.tar.bz2 linux-6b84202c946cd3da3a8daa92c682510e9ed80321.zip |
sctp: fix the check for _sctp_walk_params and _sctp_walk_errors
Commit b1f5bfc27a19 ("sctp: don't dereference ptr before leaving
_sctp_walk_{params, errors}()") tried to fix the issue that it
may overstep the chunk end for _sctp_walk_{params, errors} with
'chunk_end > offset(length) + sizeof(length)'.
But it introduced a side effect: When processing INIT, it verifies
the chunks with 'param.v == chunk_end' after iterating all params
by sctp_walk_params(). With the check 'chunk_end > offset(length)
+ sizeof(length)', it would return when the last param is not yet
accessed. Because the last param usually is fwdtsn supported param
whose size is 4 and 'chunk_end == offset(length) + sizeof(length)'
This is a badly issue even causing sctp couldn't process 4-shakes.
Client would always get abort when connecting to server, due to
the failure of INIT chunk verification on server.
The patch is to use 'chunk_end <= offset(length) + sizeof(length)'
instead of 'chunk_end < offset(length) + sizeof(length)' for both
_sctp_walk_params and _sctp_walk_errors.
Fixes: b1f5bfc27a19 ("sctp: don't dereference ptr before leaving _sctp_walk_{params, errors}()")
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>
Diffstat (limited to 'include/net')
-rw-r--r-- | include/net/sctp/sctp.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index 980807d7506f..45fd4c6056b5 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -469,7 +469,7 @@ _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member) #define _sctp_walk_params(pos, chunk, end, member)\ for (pos.v = chunk->member;\ - (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <\ + (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\ (void *)chunk + end) &&\ pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\ ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\ @@ -481,7 +481,7 @@ _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length)) #define _sctp_walk_errors(err, chunk_hdr, end)\ for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \ sizeof(struct sctp_chunkhdr));\ - ((void *)err + offsetof(sctp_errhdr_t, length) + sizeof(err->length) <\ + ((void *)err + offsetof(sctp_errhdr_t, length) + sizeof(err->length) <=\ (void *)chunk_hdr + end) &&\ (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\ ntohs(err->length) >= sizeof(sctp_errhdr_t); \ |