diff options
| author | Xie Yongji <xieyongji@bytedance.com> | 2021-07-28 16:07:56 +0300 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2021-08-26 15:37:08 +0300 |
| commit | 152962a7dc236de90884e3e5950aae5dbada2a58 (patch) | |
| tree | ecbde7a15cd8990b4b42db9507820ae1694e928c /drivers/vhost | |
| parent | 91cc40b9f19e7af8daf0362810fedb45dae00268 (diff) | |
| download | linux-152962a7dc236de90884e3e5950aae5dbada2a58.tar.xz | |
vhost: Fix the calculation in vhost_overflow()
[ Upstream commit f7ad318ea0ad58ebe0e595e59aed270bb643b29b ]
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 <jasowang@redhat.com>
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210728130756.97-2-xieyongji@bytedance.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/vhost.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 4b5590f4e98b..93cdeb516594 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -685,10 +685,16 @@ static int 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. */ |