From: Eiichi Tsukata eiichi.tsukata@nutanix.com
stable inclusion from linux-4.19.213 commit c57fdeff69b152185fafabd37e6bfecfce51efda category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4OJ3D CVE: NA
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commit a2d859e3fc97e79d907761550dbc03ff1b36479c upstream.
sctp_make_strreset_req() makes repeated calls to sctp_addto_chunk() which will automatically account for padding on each call. inreq and outreq are already 4 bytes aligned, but the payload is not and doing SCTP_PAD4(a + b) (which _sctp_make_chunk() did implicitly here) is different from SCTP_PAD4(a) + SCTP_PAD4(b) and not enough. It led to possible attempt to use more buffer than it was allocated and triggered a BUG_ON.
Cc: Vlad Yasevich vyasevich@gmail.com Cc: Neil Horman nhorman@tuxdriver.com Cc: Greg KH gregkh@linuxfoundation.org Fixes: cc16f00f6529 ("sctp: add support for generating stream reconf ssn reset request chunk") Reported-by: Eiichi Tsukata eiichi.tsukata@nutanix.com Signed-off-by: Eiichi Tsukata eiichi.tsukata@nutanix.com Signed-off-by: Marcelo Ricardo Leitner marcelo.leitner@gmail.com Signed-off-by: Marcelo Ricardo Leitner mleitner@redhat.com Reviewed-by: Xin Long lucien.xin@gmail.com Link: https://lore.kernel.org/r/b97c1f8b0c7ff79ac4ed206fc2c49d3612e0850c.163415684... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Wang Hai wanghai38@huawei.com Reviewed-by: Wei Yongjun weiyongjun1@huawei.com Reviewed-by: Yue Haibing yuehaibing@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- net/sctp/sm_make_chunk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 0789109c2d093..35e1fb708f4a7 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -3673,7 +3673,7 @@ struct sctp_chunk *sctp_make_strreset_req( outlen = (sizeof(outreq) + stream_len) * out; inlen = (sizeof(inreq) + stream_len) * in;
- retval = sctp_make_reconf(asoc, outlen + inlen); + retval = sctp_make_reconf(asoc, SCTP_PAD4(outlen) + SCTP_PAD4(inlen)); if (!retval) return NULL;