From bb7a35f241e787b737c680f1e2b97a019cebfa63 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 13 Sep 2019 12:46:59 +0100 Subject: [PATCH] 4.19-stable patches added patches: vhost-block-speculation-of-translated-descriptors.patch vhost-make-sure-log_num-in_num.patch --- queue-4.19/series | 2 + ...peculation-of-translated-descriptors.patch | 46 ++++++++++++++++ .../vhost-make-sure-log_num-in_num.patch | 54 +++++++++++++++++++ 3 files changed, 102 insertions(+) create mode 100644 queue-4.19/vhost-block-speculation-of-translated-descriptors.patch create mode 100644 queue-4.19/vhost-make-sure-log_num-in_num.patch diff --git a/queue-4.19/series b/queue-4.19/series index e1541381ff4..85c8af2a357 100644 --- a/queue-4.19/series +++ b/queue-4.19/series @@ -186,3 +186,5 @@ ext4-unsigned-int-compared-against-zero.patch pci-reset-both-nvidia-gpu-and-hda-in-thinkpad-p50-wo.patch powerpc-tm-remove-msr_tm_active.patch powerpc-tm-fix-restoring-fp-vmx-facility-incorrectly.patch +vhost-block-speculation-of-translated-descriptors.patch +vhost-make-sure-log_num-in_num.patch diff --git a/queue-4.19/vhost-block-speculation-of-translated-descriptors.patch b/queue-4.19/vhost-block-speculation-of-translated-descriptors.patch new file mode 100644 index 00000000000..0984a7e71ed --- /dev/null +++ b/queue-4.19/vhost-block-speculation-of-translated-descriptors.patch @@ -0,0 +1,46 @@ +From a89db445fbd7f1f8457b03759aa7343fa530ef6b Mon Sep 17 00:00:00 2001 +From: "Michael S. Tsirkin" +Date: Sun, 8 Sep 2019 07:04:08 -0400 +Subject: vhost: block speculation of translated descriptors + +From: Michael S. Tsirkin + +commit a89db445fbd7f1f8457b03759aa7343fa530ef6b upstream. + +iovec addresses coming from vhost are assumed to be +pre-validated, but in fact can be speculated to a value +out of range. + +Userspace address are later validated with array_index_nospec so we can +be sure kernel info does not leak through these addresses, but vhost +must also not leak userspace info outside the allowed memory table to +guests. + +Following the defence in depth principle, make sure +the address is not validated out of node range. + +Signed-off-by: Michael S. Tsirkin +Cc: stable@vger.kernel.org +Acked-by: Jason Wang +Tested-by: Jason Wang +Signed-off-by: Greg Kroah-Hartman + +--- + drivers/vhost/vhost.c | 6 ++++-- + 1 file changed, 4 insertions(+), 2 deletions(-) + +--- a/drivers/vhost/vhost.c ++++ b/drivers/vhost/vhost.c +@@ -1966,8 +1966,10 @@ static int translate_desc(struct vhost_v + _iov = iov + ret; + size = node->size - addr + node->start; + _iov->iov_len = min((u64)len - s, size); +- _iov->iov_base = (void __user *)(unsigned long) +- (node->userspace_addr + addr - node->start); ++ _iov->iov_base = (void __user *) ++ ((unsigned long)node->userspace_addr + ++ array_index_nospec((unsigned long)(addr - node->start), ++ node->size)); + s += size; + addr += size; + ++ret; diff --git a/queue-4.19/vhost-make-sure-log_num-in_num.patch b/queue-4.19/vhost-make-sure-log_num-in_num.patch new file mode 100644 index 00000000000..2a5a6284125 --- /dev/null +++ b/queue-4.19/vhost-make-sure-log_num-in_num.patch @@ -0,0 +1,54 @@ +From 060423bfdee3f8bc6e2c1bac97de24d5415e2bc4 Mon Sep 17 00:00:00 2001 +From: yongduan +Date: Wed, 11 Sep 2019 17:44:24 +0800 +Subject: vhost: make sure log_num < in_num + +From: yongduan + +commit 060423bfdee3f8bc6e2c1bac97de24d5415e2bc4 upstream. + +The code assumes log_num < in_num everywhere, and that is true as long as +in_num is incremented by descriptor iov count, and log_num by 1. However +this breaks if there's a zero sized descriptor. + +As a result, if a malicious guest creates a vring desc with desc.len = 0, +it may cause the host kernel to crash by overflowing the log array. This +bug can be triggered during the VM migration. + +There's no need to log when desc.len = 0, so just don't increment log_num +in this case. + +Fixes: 3a4d5c94e959 ("vhost_net: a kernel-level virtio server") +Cc: stable@vger.kernel.org +Reviewed-by: Lidong Chen +Signed-off-by: ruippan +Signed-off-by: yongduan +Acked-by: Michael S. Tsirkin +Reviewed-by: Tyler Hicks +Signed-off-by: Michael S. Tsirkin +Signed-off-by: Greg Kroah-Hartman + +--- + drivers/vhost/vhost.c | 4 ++-- + 1 file changed, 2 insertions(+), 2 deletions(-) + +--- a/drivers/vhost/vhost.c ++++ b/drivers/vhost/vhost.c +@@ -2075,7 +2075,7 @@ static int get_indirect(struct vhost_vir + /* If this is an input descriptor, increment that count. */ + if (access == VHOST_ACCESS_WO) { + *in_num += ret; +- if (unlikely(log)) { ++ if (unlikely(log && ret)) { + log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); + log[*log_num].len = vhost32_to_cpu(vq, desc.len); + ++*log_num; +@@ -2218,7 +2218,7 @@ int vhost_get_vq_desc(struct vhost_virtq + /* If this is an input descriptor, + * increment that count. */ + *in_num += ret; +- if (unlikely(log)) { ++ if (unlikely(log && ret)) { + log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); + log[*log_num].len = vhost32_to_cpu(vq, desc.len); + ++*log_num; -- 2.47.3