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author | Seth Forshee <seth.forshee@canonical.com> | 2014-11-25 20:28:24 -0600 |
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committer | David S. Miller <davem@davemloft.net> | 2014-12-02 19:24:13 -0800 |
commit | 8d609725d4357f499e2103e46011308b32f53513 (patch) | |
tree | f7a4035a4042165fb0fd9ced5d86ab9e350e6560 /drivers/net/xen-netfront.c | |
parent | 7fa2955ff70ce4532f144d26b8a087095f9c9ffc (diff) | |
download | linux-stable-8d609725d4357f499e2103e46011308b32f53513.tar.gz linux-stable-8d609725d4357f499e2103e46011308b32f53513.tar.bz2 linux-stable-8d609725d4357f499e2103e46011308b32f53513.zip |
xen-netfront: Remove BUGs on paged skb data which crosses a page boundary
These BUGs can be erroneously triggered by frags which refer to
tail pages within a compound page. The data in these pages may
overrun the hardware page while still being contained within the
compound page, but since compound_order() evaluates to 0 for tail
pages the assertion fails. The code already iterates through
subsequent pages correctly in this scenario, so the BUGs are
unnecessary and can be removed.
Fixes: f36c374782e4 ("xen/netfront: handle compound page fragments on transmit")
Cc: <stable@vger.kernel.org> # 3.7+
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/xen-netfront.c')
-rw-r--r-- | drivers/net/xen-netfront.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index cca871346a0f..ece8d1804d13 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -496,9 +496,6 @@ static void xennet_make_frags(struct sk_buff *skb, struct netfront_queue *queue, len = skb_frag_size(frag); offset = frag->page_offset; - /* Data must not cross a page boundary. */ - BUG_ON(len + offset > PAGE_SIZE<<compound_order(page)); - /* Skip unused frames from start of page */ page += offset >> PAGE_SHIFT; offset &= ~PAGE_MASK; @@ -506,8 +503,6 @@ static void xennet_make_frags(struct sk_buff *skb, struct netfront_queue *queue, while (len > 0) { unsigned long bytes; - BUG_ON(offset >= PAGE_SIZE); - bytes = PAGE_SIZE - offset; if (bytes > len) bytes = len; |