From 7a40f1f18a88c6d43c8725d7f45146480a79fde1 Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Fri, 21 Apr 2023 11:55:52 -0400 Subject: fs: dlm: stop unnecessarily filling zero ms_extra bytes Commit 7175e131ebba ("fs: dlm: fix invalid derefence of sb_lvbptr") fixes an issue when the lkb->lkb_lvbptr set to an dangled pointer and an followed memcpy() would fail. It was fixed by an additional check of DLM_LKF_VALBLK flag. The mentioned commit forgot to add an additional check if DLM_LKF_VALBLK is set for the additional amount of LVB data allocated in a dlm message. This patch is changing the message allocation to check additionally if DLM_LKF_VALBLK is set otherwise a dangled lkb->lkb_lvbptr pointer would allocated zero LVB message data which not gets filled with actual data. This patch is however only a cleanup to reduce the amount of zero bytes transmitted over network as receive_lvb() will only evaluates message LVB data if DLM_LKF_VALBLK is set. Signed-off-by: Alexander Aring Signed-off-by: David Teigland --- fs/dlm/lock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/dlm') diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index 1582c8b1404c..debf8a55ad7d 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -3381,7 +3381,7 @@ static int create_message(struct dlm_rsb *r, struct dlm_lkb *lkb, case DLM_MSG_REQUEST_REPLY: case DLM_MSG_CONVERT_REPLY: case DLM_MSG_GRANT: - if (lkb && lkb->lkb_lvbptr) + if (lkb && lkb->lkb_lvbptr && (lkb->lkb_exflags & DLM_LKF_VALBLK)) mb_len += r->res_ls->ls_lvblen; break; } -- cgit