From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Subject: [PATCH] xen: arm: do not BUG on guest paddrs which are very high Date: Thu, 5 Dec 2013 12:53:28 +0000 Message-ID: <1386248008-10820-1-git-send-email-ian.campbell@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: julien.grall@linaro.org, tim@xen.org, Ian Campbell , stefano.stabellini@eu.citrix.com List-Id: xen-devel@lists.xenproject.org The BUG_ON in p2m_map_first was over aggressive since the paddr_t can have come from the guest, via add_to_physmap. Instead return failure to the caller. Also the check was simultaneously too lose. The valid offsets are 0..P2M_FIRST_ENTRIES-1 inclusive. Signed-off-by: Ian Campbell --- xen/arch/arm/p2m.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c index 1d5c841..cd134d4 100644 --- a/xen/arch/arm/p2m.c +++ b/xen/arch/arm/p2m.c @@ -58,7 +58,8 @@ static lpae_t *p2m_map_first(struct p2m_domain *p2m, paddr_t addr) { struct page_info *page; - BUG_ON(first_linear_offset(addr) > P2M_FIRST_ENTRIES); + if ( first_linear_offset(addr) >= P2M_FIRST_ENTRIES ) + return NULL; page = p2m->first_level + p2m_first_level_index(addr); @@ -80,6 +81,8 @@ paddr_t p2m_lookup(struct domain *d, paddr_t paddr) spin_lock(&p2m->lock); first = p2m_map_first(p2m, paddr); + if ( !first ) + goto done; pte = first[first_table_offset(paddr)]; if ( !pte.p2m.valid || !pte.p2m.table ) @@ -181,6 +184,11 @@ static int create_p2m_entries(struct domain *d, { if ( first ) unmap_domain_page(first); first = p2m_map_first(p2m, addr); + if ( !first ) + { + rc = -EINVAL; + goto out; + } cur_first_page = p2m_first_level_index(addr); } -- 1.7.10.4