2012-05-15 15:57:16

by Gustavo Padovan

Subject: [PATCH] Bluetooth: Fix wrong set of skb fragments

If alloc() fails we let the frags linked list with garbage value(the err
ptr value) in its last element.

Reported-by: Mat Martineau <[email protected]>
Signed-off-by: Gustavo Padovan <[email protected]>
---
net/bluetooth/l2cap_core.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 869beb3..8c8a803 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -1836,13 +1836,17 @@ static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan,
/* Continuation fragments (no L2CAP header) */
frag = &skb_shinfo(skb)->frag_list;
while (len) {
+ struct sk_buff *tmp;
+
count = min_t(unsigned int, conn->mtu, len);

- *frag = chan->ops->alloc_skb(chan, count,
+ tmp = chan->ops->alloc_skb(chan, count,
msg->msg_flags & MSG_DONTWAIT);
+ if (IS_ERR(tmp))
+ return PTR_ERR(tmp);
+
+ *frag = tmp;

- if (IS_ERR(*frag))
- return PTR_ERR(*frag);
if (memcpy_fromiovec(skb_put(*frag, count), msg->msg_iov, count))
return -EFAULT;

--
1.7.10.1

2012-05-15 16:09:43

by Mat Martineau

Subject: Re: [PATCH] Bluetooth: Fix wrong set of skb fragments

Gustavo -

On Tue, 15 May 2012, Gustavo Padovan wrote:

> If alloc() fails we let the frags linked list with garbage value(the err
> ptr value) in its last element.

Change "let" to "left", maybe? Also missing a space after the first
"value".

> Reported-by: Mat Martineau <[email protected]>
> Signed-off-by: Gustavo Padovan <[email protected]>
> ---
> net/bluetooth/l2cap_core.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index 869beb3..8c8a803 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -1836,13 +1836,17 @@ static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan,
> /* Continuation fragments (no L2CAP header) */
> frag = &skb_shinfo(skb)->frag_list;
> while (len) {
> + struct sk_buff *tmp;
> +
> count = min_t(unsigned int, conn->mtu, len);
>
> - *frag = chan->ops->alloc_skb(chan, count,
> + tmp = chan->ops->alloc_skb(chan, count,
> msg->msg_flags & MSG_DONTWAIT);

Fix up the alignment of the continuation line here.

> + if (IS_ERR(tmp))
> + return PTR_ERR(tmp);
> +
> + *frag = tmp;
>
> - if (IS_ERR(*frag))
> - return PTR_ERR(*frag);
> if (memcpy_fromiovec(skb_put(*frag, count), msg->msg_iov, count))
> return -EFAULT;
>
> --
> 1.7.10.1

Other than that, it looks good to me!

--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum