From 5b16d52be00e78622d0783f5c57474137a60e5a3 Mon Sep 17 00:00:00 2001 From: Liang Zhen Date: Wed, 2 Mar 2016 17:01:45 -0500 Subject: [PATCH] staging: lustre: recv could access freed message When lnet_parse_put calls lnet_ptl_match_md, this function can attach current message on the delayed list if there is no match. It means this message can be taken over and freed by another thread who is posting new MD, then it is not safe for caller of lnet_parse_put to check this message again. This patch fixes this issue by adding a local variable "ready_delay" to store corresponding status of lnet_msg, so lnet doesn't need to check the message again if lnet_ptl_match_md returned MATCH_NONE for it. Signed-off-by: Liang Zhen Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-7324 Reviewed-on: http://review.whamcloud.com/17065 Reviewed-by: Doug Oucharek Reviewed-by: Faccini Bruno Reviewed-by: Oleg Drokin Signed-off-by: Greg Kroah-Hartman --- drivers/staging/lustre/lnet/lnet/lib-move.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/staging/lustre/lnet/lnet/lib-move.c b/drivers/staging/lustre/lnet/lnet/lib-move.c index 7bc3e91e7860..fa5b7cd36aea 100644 --- a/drivers/staging/lustre/lnet/lnet/lib-move.c +++ b/drivers/staging/lustre/lnet/lnet/lib-move.c @@ -1466,6 +1466,7 @@ lnet_parse_put(lnet_ni_t *ni, lnet_msg_t *msg) { lnet_hdr_t *hdr = &msg->msg_hdr; struct lnet_match_info info; + bool ready_delay; int rc; /* Convert put fields to host byte order */ @@ -1482,6 +1483,7 @@ lnet_parse_put(lnet_ni_t *ni, lnet_msg_t *msg) info.mi_mbits = hdr->msg.put.match_bits; msg->msg_rx_ready_delay = !ni->ni_lnd->lnd_eager_recv; + ready_delay = msg->msg_rx_ready_delay; again: rc = lnet_ptl_match_md(&info, msg); @@ -1494,12 +1496,18 @@ lnet_parse_put(lnet_ni_t *ni, lnet_msg_t *msg) return 0; case LNET_MATCHMD_NONE: - if (msg->msg_rx_delayed) /* attached on delayed list */ + /** + * no eager_recv or has already called it, should + * have been attached on delayed list + */ + if (ready_delay) return 0; rc = lnet_ni_eager_recv(ni, msg); - if (!rc) + if (!rc) { + ready_delay = true; goto again; + } /* fall through */ case LNET_MATCHMD_DROP: -- 2.20.1