diff options
author | Xin Long <lucien.xin@gmail.com> | 2017-07-26 16:24:59 +0800 |
---|---|---|
committer | Sasha Levin <alexander.levin@verizon.com> | 2017-09-10 16:36:03 -0400 |
commit | 34e5d770ff45af63e2d808e7f062251a564a9727 (patch) | |
tree | 6ab72564c256d6bd785d832624b6a9027959f846 | |
parent | 943eb7384e1a4910ea02365591be1d9685adc3c3 (diff) |
sctp: fix the check for _sctp_walk_params and _sctp_walk_errors
[ Upstream commit 6b84202c946cd3da3a8daa92c682510e9ed80321 ]
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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
-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 48e14dbd2d23..d33b17ba51d2 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -444,7 +444,7 @@ _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(sctp_paramhdr_t);\ @@ -456,7 +456,7 @@ _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(sctp_chunkhdr_t));\ - ((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); \ |