On Fri, 2014-04-25 at 17:02 +0200, Svenning Sørensen wrote: > This patch adds a guard against coalescing packets received by buggy network > drivers that don't initialize skb->tail properly. > > Coalescing such packets will corrupt data in a way that makes it hard to > track down the real cause of the problem. Observed symptoms are a flood of > WARNs by tcp_recvmsg at random times, leaving no clear indication as to why > the packet buffers were corrupted. See for example this thread: > https://groups.google.com/forum/#!topic/linux.kernel/A8ZI9aXooSU > > Obviously the correct thing to do is fixing the drivers in question (eg. by > using skb_put() instead of just setting skb->len) - this patch will > hopefully > help to track them down with less effort than I had to put into it :) > > NB: in my case it was an out-of-tree Bluegiga WiFi driver; a quick look > indicates > that there are in-tree drivers (for hardware that I don't own) with the > same bug. > > > Signed-off-by: Svenning Soerensen <[email protected]>
If you want a debugging patch, this should happen way before TCP stack or even IP stack. Say you want to use this buggy driver on a router, this code path will never bit hit. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
