From 0e398290cff997610b66e73573faaee70c9a700e Mon Sep 17 00:00:00 2001 From: Xie Yongji Date: Wed, 28 Jul 2021 21:07:55 +0800 Subject: vhost-vdpa: Fix integer overflow in vhost_vdpa_process_iotlb_update() The "msg->iova + msg->size" addition can have an integer overflow if the iotlb message is from a malicious user space application. So let's fix it. Fixes: 1b48dc03e575 ("vhost: vdpa: report iova range") Reported-by: Dan Carpenter Signed-off-by: Xie Yongji Acked-by: Jason Wang Link: https://lore.kernel.org/r/20210728130756.97-1-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin --- drivers/vhost/vdpa.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/vhost') diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 210ab35a7ebf..9479f7f79217 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -614,7 +614,8 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v, long pinned; int ret = 0; - if (msg->iova < v->range.first || + if (msg->iova < v->range.first || !msg->size || + msg->iova > U64_MAX - msg->size + 1 || msg->iova + msg->size - 1 > v->range.last) return -EINVAL; -- cgit v1.2.3 From f7ad318ea0ad58ebe0e595e59aed270bb643b29b Mon Sep 17 00:00:00 2001 From: Xie Yongji Date: Wed, 28 Jul 2021 21:07:56 +0800 Subject: vhost: Fix the calculation in vhost_overflow() This fixes the incorrect calculation for integer overflow when the last address of iova range is 0xffffffff. Fixes: ec33d031a14b ("vhost: detect 32 bit integer wrap around") Reported-by: Jason Wang Signed-off-by: Xie Yongji Acked-by: Jason Wang Link: https://lore.kernel.org/r/20210728130756.97-2-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin --- drivers/vhost/vhost.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'drivers/vhost') diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index b9e853e6094d..59edb5a1ffe2 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -735,10 +735,16 @@ static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz) (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); } +/* Make sure 64 bit math will not overflow. */ static bool vhost_overflow(u64 uaddr, u64 size) { - /* Make sure 64 bit math will not overflow. */ - return uaddr > ULONG_MAX || size > ULONG_MAX || uaddr > ULONG_MAX - size; + if (uaddr > ULONG_MAX || size > ULONG_MAX) + return true; + + if (!size) + return false; + + return uaddr > ULONG_MAX - size + 1; } /* Caller should have vq mutex and device mutex. */ -- cgit v1.2.3 From e74cfa91f42c50f7f649b0eca46aa049754ccdbd Mon Sep 17 00:00:00 2001 From: Neeraj Upadhyay Date: Fri, 25 Jun 2021 08:55:02 +0530 Subject: vringh: Use wiov->used to check for read/write desc order As __vringh_iov() traverses a descriptor chain, it populates each descriptor entry into either read or write vring iov and increments that iov's ->used member. So, as we iterate over a descriptor chain, at any point, (riov/wriov)->used value gives the number of descriptor enteries available, which are to be read or written by the device. As all read iovs must precede the write iovs, wiov->used should be zero when we are traversing a read descriptor. Current code checks for wiov->i, to figure out whether any previous entry in the current descriptor chain was a write descriptor. However, iov->i is only incremented, when these vring iovs are consumed, at a later point, and remain 0 in __vringh_iov(). So, correct the check for read and write descriptor order, to use wiov->used. Acked-by: Jason Wang Reviewed-by: Stefano Garzarella Signed-off-by: Neeraj Upadhyay Link: https://lore.kernel.org/r/1624591502-4827-1-git-send-email-neeraju@codeaurora.org Signed-off-by: Michael S. Tsirkin --- drivers/vhost/vringh.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/vhost') diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c index 4af8fa259d65..14e2043d7685 100644 --- a/drivers/vhost/vringh.c +++ b/drivers/vhost/vringh.c @@ -359,7 +359,7 @@ __vringh_iov(struct vringh *vrh, u16 i, iov = wiov; else { iov = riov; - if (unlikely(wiov && wiov->i)) { + if (unlikely(wiov && wiov->used)) { vringh_bad("Readable desc %p after writable", &descs[i]); err = -EINVAL; -- cgit v1.2.3