From 5aecaabb126fbed3ce66a8ee7b0ee125e7de6073 Mon Sep 17 00:00:00 2001 From: Xie Yongji Date: Tue, 18 Oct 2022 19:55:56 +0800 Subject: [PATCH] vringh: Fix loop descriptors check in the indirect cases stable inclusion from stable-v5.10.122 commit b6ea26873edbd9ca3c0c338c9de856de7f1fcede category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5W6OE Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b6ea26873edbd9ca3c0c338c9de856de7f1fcede -------------------------------- [ Upstream commit dbd29e0752286af74243cf891accf472b2f3edd8 ] We should use size of descriptor chain to test loop condition in the indirect case. And another statistical count is also introduced for indirect descriptors to avoid conflict with the statistical count of direct descriptors. Fixes: f87d0fbb5798 ("vringh: host-side implementation of virtio rings.") Signed-off-by: Xie Yongji Signed-off-by: Fam Zheng Message-Id: <20220505100910.137-1-xieyongji@bytedance.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: Sasha Levin Signed-off-by: Zheng Zengkai Reviewed-by: Wei Li --- drivers/vhost/vringh.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c index 0bd7e64331f0..5a0340c85dc6 100644 --- a/drivers/vhost/vringh.c +++ b/drivers/vhost/vringh.c @@ -274,7 +274,7 @@ __vringh_iov(struct vringh *vrh, u16 i, int (*copy)(const struct vringh *vrh, void *dst, const void *src, size_t len)) { - int err, count = 0, up_next, desc_max; + int err, count = 0, indirect_count = 0, up_next, desc_max; struct vring_desc desc, *descs; struct vringh_range range = { -1ULL, 0 }, slowrange; bool slow = false; @@ -331,7 +331,12 @@ __vringh_iov(struct vringh *vrh, u16 i, continue; } - if (count++ == vrh->vring.num) { + if (up_next == -1) + count++; + else + indirect_count++; + + if (count > vrh->vring.num || indirect_count > desc_max) { vringh_bad("Descriptor loop in %p", descs); err = -ELOOP; goto fail; @@ -393,6 +398,7 @@ __vringh_iov(struct vringh *vrh, u16 i, i = return_from_indirect(vrh, &up_next, &descs, &desc_max); slow = false; + indirect_count = 0; } else break; } -- GitLab