From dfaa2abea1108c49862725af956033478f06d478 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Amos Kong Date: Mon, 8 Dec 2014 14:48:35 -0600 Subject: [CHANGE 09/12] migration: fix parameter validation on ram load (CVE-2014-7840) To: rhvirt-patches@redhat.com, jen@redhat.com RH-Author: Amos Kong Message-id: <1418050115-24916-1-git-send-email-akong@redhat.com> Patchwork-id: 62761 O-Subject: [RHEV-7.1 qemu-kvm-rhev PATCH] migration: fix parameter validation on ram load (CVE-2014-7840) Bugzilla: 1163079 RH-Acked-by: Juan Quintela RH-Acked-by: Dr. David Alan Gilbert (git) RH-Acked-by: Michael S. Tsirkin From: Michael S. Tsirkin During migration, the values read from migration stream during ram load are not validated. Especially offset in host_from_stream_offset() and also the length of the writes in the callers of said function. To fix this, we need to make sure that the [offset, offset + length] range fits into one of the allocated memory regions. Validating addr < len should be sufficient since data seems to always be managed in TARGET_PAGE_SIZE chunks. Fixes: CVE-2014-7840 Note: follow-up patches add extra checks on each block->host access. Signed-off-by: Michael S. Tsirkin Reviewed-by: Paolo Bonzini Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Amit Shah (cherry picked from commit 0be839a2701369f669532ea5884c15bead1c6e08) Signed-off-by: Amos Kong Signed-off-by: Jeff E. Nelson --- arch_init.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch_init.c b/arch_init.c index b8427bc..ef246be 100644 --- a/arch_init.c +++ b/arch_init.c @@ -1013,7 +1013,7 @@ static inline void *host_from_stream_offset(QEMUFile *f, uint8_t len; if (flags & RAM_SAVE_FLAG_CONTINUE) { - if (!block) { + if (!block || block->length <= offset) { error_report("Ack, bad migration stream!"); return NULL; } @@ -1026,8 +1026,9 @@ static inline void *host_from_stream_offset(QEMUFile *f, id[len] = 0; QTAILQ_FOREACH(block, &ram_list.blocks, next) { - if (!strncmp(id, block->idstr, sizeof(id))) + if (!strncmp(id, block->idstr, sizeof(id)) && block->length > offset) { return memory_region_get_ram_ptr(block->mr) + offset; + } } error_report("Can't find block %s!", id); -- 2.1.0