aoe: print warning regarding a common reason for dropped transmits

DISCUSSION Dan Carpenter 2 participants 4 messages Oct 23, 2012 – Oct 24, 2012 Kernel janitors

Share & tools

Dan Carpenter

author

2012-10-23 17:28 UTC #0 lore raw

Hello Ed L. Cashin,

The patch 6fde53abc51d: "aoe: print warning regarding a common reason for dropped transmits" from Oct 23, 2012, leads to the following warning:
drivers/block/aoe/aoenet.c:62 tx()
error: 'skb' was already used up by dev_queue_xmit()

61) if (dev_queue_xmit(skb) = NET_XMIT_DROP && net_ratelimit())
62) pr_warn("aoe: packet could not be sent on %s. %s\n",
63) skb->dev ? skb->dev->name : "netif",
64) "consider increasing tx_queue_len");

It's a use after free bug.

regards,
dan carpenter

Ed Cashin

2012-10-23 18:51 UTC #1 lore raw

Quoted 8 lines · Dan Carpenter

Hello Ed L. Cashin,
The patch 6fde53abc51d: "aoe: print warning regarding a common reason for dropped transmits" from Oct 23, 2012, leads to the following warning:
drivers/block/aoe/aoenet.c:62 tx()
error: 'skb' was already used up by dev_queue_xmit()

Quoted 6 lines

61) if (dev_queue_xmit(skb) = NET_XMIT_DROP && net_ratelimit())
62) pr_warn("aoe: packet could not be sent on %s. %s\n",
63) skb->dev ? skb->dev->name : "netif",
64) "consider increasing tx_queue_len");
It's a use after free bug.

Thanks for the report. The Documentation/SubmittingPatches says,

Please note that this tag should not be added without the reporter's permission, especially if the problem was not reported in a public forum.

Which surprisingly means that I should ask you for permission before mentioning you in a "Reported-by:" tag, even though you reported it in a public forum. So is it OK?

Signature · 2 lines

  Ed Cashin
  [email protected]

Dan Carpenter

author

2012-10-24 06:26 UTC #2 lore raw

In reply to Dan Carpenter

Quoted 19 lines · Ed Cashin

Quoted 8 lines · Dan Carpenter
Hello Ed L. Cashin,
The patch 6fde53abc51d: "aoe: print warning regarding a common reason for dropped transmits" from Oct 23, 2012, leads to the following warning:
drivers/block/aoe/aoenet.c:62 tx()
error: 'skb' was already used up by dev_queue_xmit()
Quoted 6 lines
61) if (dev_queue_xmit(skb) = NET_XMIT_DROP && net_ratelimit())
62) pr_warn("aoe: packet could not be sent on %s. %s\n",
63) skb->dev ? skb->dev->name : "netif",
64) "consider increasing tx_queue_len");
It's a use after free bug.
Thanks for the report. The Documentation/SubmittingPatches says,

Quoted 7 lines

Please note that this tag should not be added without the reporter's permission, especially if the problem was not reported in a public forum.
Which surprisingly means that I should ask you for permission before mentioning you in a "Reported-by:" tag, even though you reported it in a public forum. So is it OK?

Yes. Reported-by credits are always welcome.

I think that documentation is wrong. If the email was reported to a mailing list or bugzilla then we normally add a reported-by by default.

regards,
dan carpenter

Ed Cashin

2012-10-24 18:22 UTC #3 lore raw

In reply to Dan Carpenter

Quoted 11 lines · Dan Carpenter

Quoted 10 lines · Ed Cashin
Quoted 8 lines · Dan Carpenter
Hello Ed L. Cashin,
The patch 6fde53abc51d: "aoe: print warning regarding a common reason for dropped transmits" from Oct 23, 2012, leads to the following warning:
drivers/block/aoe/aoenet.c:62 tx()
error: 'skb' was already used up by dev_queue_xmit()

Quoted 6 lines

Quoted 6 lines
Quoted 6 lines
61) if (dev_queue_xmit(skb) = NET_XMIT_DROP && net_ratelimit())
62) pr_warn("aoe: packet could not be sent on %s. %s\n",
63) skb->dev ? skb->dev->name : "netif",
64) "consider increasing tx_queue_len");
It's a use after free bug.

By the way, what tool is generating that warning?

Thanks.

Signature · 2 lines

  Ed Cashin
  [email protected]