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| author | Xin Long <lucien.xin@gmail.com> | 2023-04-10 15:43:30 -0400 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2023-04-13 10:01:59 +0200 |
| commit | 32832a2caf82663870126c5186cf8f86c8b2a649 (patch) | |
| tree | c53ebff8f60f06b37bd7b35c9aaacc3b270c931e | |
| parent | 6417070918de3bcdbe0646e7256dae58fd8083ba (diff) | |
| download | lwn-32832a2caf82663870126c5186cf8f86c8b2a649.tar.gz lwn-32832a2caf82663870126c5186cf8f86c8b2a649.zip | |
sctp: fix a potential overflow in sctp_ifwdtsn_skip
Currently, when traversing ifwdtsn skips with _sctp_walk_ifwdtsn, it only
checks the pos against the end of the chunk. However, the data left for
the last pos may be < sizeof(struct sctp_ifwdtsn_skip), and dereference
it as struct sctp_ifwdtsn_skip may cause coverflow.
This patch fixes it by checking the pos against "the end of the chunk -
sizeof(struct sctp_ifwdtsn_skip)" in sctp_ifwdtsn_skip, similar to
sctp_fwdtsn_skip.
Fixes: 0fc2ea922c8a ("sctp: implement validate_ftsn for sctp_stream_interleave")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Link: https://lore.kernel.org/r/2a71bffcd80b4f2c61fac6d344bb2f11c8fd74f7.1681155810.git.lucien.xin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | net/sctp/stream_interleave.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/sctp/stream_interleave.c b/net/sctp/stream_interleave.c index 94727feb07b3..b046b11200c9 100644 --- a/net/sctp/stream_interleave.c +++ b/net/sctp/stream_interleave.c @@ -1154,7 +1154,8 @@ static void sctp_generate_iftsn(struct sctp_outq *q, __u32 ctsn) #define _sctp_walk_ifwdtsn(pos, chunk, end) \ for (pos = chunk->subh.ifwdtsn_hdr->skip; \ - (void *)pos < (void *)chunk->subh.ifwdtsn_hdr->skip + (end); pos++) + (void *)pos <= (void *)chunk->subh.ifwdtsn_hdr->skip + (end) - \ + sizeof(struct sctp_ifwdtsn_skip); pos++) #define sctp_walk_ifwdtsn(pos, ch) \ _sctp_walk_ifwdtsn((pos), (ch), ntohs((ch)->chunk_hdr->length) - \ |