Re: [PATCH net v5 0/8] xsk: fix bugs around xsk skb allocation

Jason Xing
2026-05-05T19:09:54Z

On Tue, May 5, 2026 at 6:45 PM Alexander Lobakin
<aleksander.lobakin@intel.com> wrote:
>
> From: Jason Xing <kerneljasonxing@gmail.com>
> Date: Sat, 2 May 2026 23:07:14 +0300
>
> > From: Jason Xing <kernelxing@tencent.com>
> >
> > There are rare issues around xsk_build_skb(). Some of them
> > were founded by Sashiko[1][2].
>
> For the series:
>
> Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
>
> Just don't forget to look at Sashiko's replies, I haven't looked deep
> into them, so can't say whether anything there makes sense.

Thanks for the review. I'm currently away from the keyboard because of
the long vacation. Now I'll handle them one by one in the following
two days. Hopefully, I can manage it today :P

Thanks,
Jason

>
> >
> > [1]: https://lore.kernel.org/all/20260415082654.21026-1-kerneljasonxing@gmail.com/
> > [2]: https://lore.kernel.org/all/20260418045644.28612-1-kerneljasonxing@gmail.com/
> >
> > ---
> > v5
> > Link: https://lore.kernel.org/all/20260424053816.27965-1-kerneljasonxing@gmail.com/
> > 1. reword patch 3
> > 2. adjust the order of patch 6 that is now moved up to be patch 2)
> > 3. use helper in patch (Stan)
> >
> > v4
> > Link: https://lore.kernel.org/all/20260422033650.68457-1-kerneljasonxing@gmail.com/
> > 1. fix 32-bit arch issue in patch 8 (Alexander && Maciej)
> > 2. add acked-by tags (Stan)
> >
> > v3
> > Link: https://lore.kernel.org/all/20260420082805.14844-1-kerneljasonxing@gmail.com/
> > 1. use !xs->skb as the indicator of first frag in patch 3 (Stan)
> > 2. move init skb after it's allocated successfully, so patch 4,5,6 have
> > been adjusted accordingly (Stan)
> > 3. do not support 32-bit arch (Stan)
> > 4. add acked-by tags (Stan)
> >
> > v2
> > Link: https://lore.kernel.org/all/20260418045644.28612-1-kerneljasonxing@gmail.com/#t
> > 1. add four patches spotted by sashiko to fix buggy pre-existing
> > behavior
> > 2. adjust the order of 8 patches.
> >
> >
> >
> > Jason Xing (8):
> > xsk: reject sw-csum UMEM binding to IFF_TX_SKB_NO_LINEAR devices
> > xsk: free the skb when hitting the upper bound MAX_SKB_FRAGS
> > xsk: handle NULL dereference of the skb without frags issue
> > xsk: fix use-after-free of xs->skb in xsk_build_skb() free_err path
> > xsk: prevent CQ desync when freeing half-built skbs in xsk_build_skb()
> > xsk: avoid skb leak in XDP_TX_METADATA case
> > xsk: fix xsk_addrs slab leak on multi-buffer error path
> > xsk: fix u64 descriptor address truncation on 32-bit architectures
> >
> > net/xdp/xsk.c | 115 ++++++++++++++++++++++++++--------------
> > net/xdp/xsk_buff_pool.c | 3 ++
> > 2 files changed, 77 insertions(+), 41 deletions(-)
>
> Thanks,
> Olek