[DLM] fix send_args() lvb copying (da49f36f) · Commits · 戴 / test

The send_args() function is used to copy parameters into a message for a number different message types. Only some of those types are set up beforehand (in create_message) to include space for sending lvb data. send_args was wrongly copying the lvb for all message types as long as the lock had an lvb. This means that the lvb data was being written past the end of the message into unknown space. Signed-off-by:

David Teigland <teigland@redhat.com> Signed-off-by:

Steven Whitehouse <swhiteho@redhat.com>

fs/dlm/lock.c

+16 −4

Original line number	Diff line number	Diff line
		@@ -2144,12 +2144,24 @@ static void send_args(struct dlm_rsb r, struct dlm_lkb lkb,
		if (lkb->lkb_astaddr)
		ms->m_asts \|= AST_COMP;

		if (ms->m_type == DLM_MSG_REQUEST \|\| ms->m_type == DLM_MSG_LOOKUP)
		memcpy(ms->m_extra, r->res_name, r->res_length);
		/* compare with switch in create_message; send_remove() doesn't
		use send_args() */

		else if (lkb->lkb_lvbptr)
		switch (ms->m_type) {
		case DLM_MSG_REQUEST:
		case DLM_MSG_LOOKUP:
		memcpy(ms->m_extra, r->res_name, r->res_length);
		break;
		case DLM_MSG_CONVERT:
		case DLM_MSG_UNLOCK:
		case DLM_MSG_REQUEST_REPLY:
		case DLM_MSG_CONVERT_REPLY:
		case DLM_MSG_GRANT:
		if (!lkb->lkb_lvbptr)
		break;
		memcpy(ms->m_extra, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);

		break;
		}
		}

		static int send_common(struct dlm_rsb r, struct dlm_lkb lkb, int mstype)

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