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authorXin Long <lucien.xin@gmail.com>2021-10-20 07:42:47 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-11-02 18:25:13 +0100
commita9ded117c98b0aa20e20cb82943ba5f0c34c8881 (patch)
tree5b58215377d9b85d47fb9e66637730196f0fac7f
parent32ceffec2a9a23346d33c0b48f4a7269ede2480d (diff)
sctp: add vtag check in sctp_sf_ootb
[ Upstream commit 9d02831e517aa36ee6bdb453a0eb47bd49923fe3 ] sctp_sf_ootb() is called when processing DATA chunk in closed state, and many other places are also using it. The vtag in the chunk's sctphdr should be verified, otherwise, as later in chunk length check, it may send abort with the existent asoc's vtag, which can be exploited by one to cook a malicious chunk to terminate a SCTP asoc. When fails to verify the vtag from the chunk, this patch sets asoc to NULL, so that the abort will be made with the vtag from the received chunk later. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--net/sctp/sm_statefuns.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index c3cb0ae7df2b..b26067798dbf 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -3498,6 +3498,9 @@ enum sctp_disposition sctp_sf_ootb(struct net *net,
SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
+ if (asoc && !sctp_vtag_verify(chunk, asoc))
+ asoc = NULL;
+
ch = (struct sctp_chunkhdr *)chunk->chunk_hdr;
do {
/* Report violation if the chunk is less then minimal */