From: Eiichi Tsukata <eiichi.tsukata@nutanix.com> stable inclusion from stable-5.10.75 commit d84a69ac410f6228873d05d35120f6bdddab7fc3 bugzilla: 182987 https://gitee.com/openeuler/kernel/issues/I4I3MP Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- 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: Chen Jun <chenjun102@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@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 fa0d96320baa..64e0f4864b73 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -3651,7 +3651,7 @@ 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; -- 2.20.1