On Fri, Aug 02, 2013 at 09:18:06AM +0200, Antonio Quartulli wrote:
On Fri, Aug 02, 2013 at 12:05:28PM +0800, Marek Lindner wrote:
On Monday, July 29, 2013 04:17:57 Antonio Quartulli wrote:
Il 27.07.2013 03:24 Linus Lüssing ha scritto:
batadv_send_skb_prepare_unicast(_4addr) might reallocate the skb's data. If it does then our ethhdr pointer is not valid anymore in batadv_send_skb_unicast(), resulting in a kernel paging error.
This patch fixes this issue by storing the few bytes we are interested in on the stack before modifying the skb.
Good fix! thanks!
However, I think it would be nice to send another patch aiming master which could polish this situation a bit better: e.g. by calling skb_reset_mac_header() in the batadv_send_skb_prepare_unicast_* functions and then get the Ethernet header with eth_hdr() right after having changed the skb.
I like that approach because it seems cleaner that way. Is there a reason not do it right away ?
I thought the second approach would consist in a bigger patch and so I preferred to send this to net and the bigger patch to net-next later.
But you may be right. The change I suggested is not really big. Linus, would you like to provide "the next" patch so that we can clearly understand if it is worth sending to net or not?
Sure! I think it could actually be a lot easier than I thought (if I didn't misread or miss something in the skb code).
Cheers,
-- Antonio Quartulli
..each of us alone is worth nothing.. Ernesto "Che" Guevara