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  1. 08 2月, 2023 1 次提交
  3. 13 12月, 2022 1 次提交
  5. 14 6月, 2022 1 次提交
    • J
      skbuff: fix coalescing for page_pool fragment recycling · 3a44f609
      由 Jean-Philippe Brucker 提交于 
      mainline inclusion
from mainline-v5.18-rc2
commit 1effe8ca
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I56XHY
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1effe8ca4e34

----------------------------------------------------------------------

Fix a use-after-free when using page_pool with page fragments. We
encountered this problem during normal RX in the hns3 driver:

(1) Initially we have three descriptors in the RX queue. The first one
    allocates PAGE1 through page_pool, and the other two allocate one
    half of PAGE2 each. Page references look like this:

                RX_BD1 _______ PAGE1
                RX_BD2 _______ PAGE2
                RX_BD3 _________/

(2) Handle RX on the first descriptor. Allocate SKB1, eventually added
    to the receive queue by tcp_queue_rcv().

(3) Handle RX on the second descriptor. Allocate SKB2 and pass it to
    netif_receive_skb():

    netif_receive_skb(SKB2)
      ip_rcv(SKB2)
        SKB3 = skb_clone(SKB2)

    SKB2 and SKB3 share a reference to PAGE2 through
    skb_shinfo()->dataref. The other ref to PAGE2 is still held by
    RX_BD3:

                      SKB2 ---+- PAGE2
                      SKB3 __/   /
                RX_BD3 _________/

 (3b) Now while handling TCP, coalesce SKB3 with SKB1:

      tcp_v4_rcv(SKB3)
        tcp_try_coalesce(to=SKB1, from=SKB3)    // succeeds
        kfree_skb_partial(SKB3)
          skb_release_data(SKB3)                // drops one dataref

                      SKB1 _____ PAGE1
                           \____
                      SKB2 _____ PAGE2
                                 /
                RX_BD3 _________/

    In skb_try_coalesce(), __skb_frag_ref() takes a page reference to
    PAGE2, where it should instead have increased the page_pool frag
    reference, pp_frag_count. Without coalescing, when releasing both
    SKB2 and SKB3, a single reference to PAGE2 would be dropped. Now
    when releasing SKB1 and SKB2, two references to PAGE2 will be
    dropped, resulting in underflow.

 (3c) Drop SKB2:

      af_packet_rcv(SKB2)
        consume_skb(SKB2)
          skb_release_data(SKB2)                // drops second dataref
            page_pool_return_skb_page(PAGE2)    // drops one pp_frag_count

                      SKB1 _____ PAGE1
                           \____
                                 PAGE2
                                 /
                RX_BD3 _________/

(4) Userspace calls recvmsg()
    Copies SKB1 and releases it. Since SKB3 was coalesced with SKB1, we
    release the SKB3 page as well:

    tcp_eat_recv_skb(SKB1)
      skb_release_data(SKB1)
        page_pool_return_skb_page(PAGE1)
        page_pool_return_skb_page(PAGE2)        // drops second pp_frag_count

(5) PAGE2 is freed, but the third RX descriptor was still using it!
    In our case this causes IOMMU faults, but it would silently corrupt
    memory if the IOMMU was disabled.

Change the logic that checks whether pp_recycle SKBs can be coalesced.
We still reject differing pp_recycle between 'from' and 'to' SKBs, but
in order to avoid the situation described above, we also reject
coalescing when both 'from' and 'to' are pp_recycled and 'from' is
cloned.

The new logic allows coalescing a cloned pp_recycle SKB into a page
refcounted one, because in this case the release (4) will drop the right
reference, the one taken by skb_try_coalesce().

Fixes: 53e0961d ("page_pool: add frag page recycling support in page pool")
Suggested-by: NAlexander Duyck <alexanderduyck@fb.com>
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: NYunsheng Lin <linyunsheng@huawei.com>
Reviewed-by: NAlexander Duyck <alexanderduyck@fb.com>
Acked-by: NIlias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJiantao Xiao <xiaojiantao1@h-partners.com>
Reviewed-by: NJian Shen <shenjian15@huawei.com>
Reviewed-by: NYue Haibing <yuehaibing@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
      3a44f609
  7. 28 5月, 2022 2 次提交
  9. 27 1月, 2022 1 次提交
  11. 14 1月, 2022 1 次提交
  13. 11 11月, 2021 4 次提交
  15. 15 10月, 2021 3 次提交
  17. 09 4月, 2021 1 次提交
  19. 08 2月, 2021 1 次提交
  21. 29 1月, 2021 2 次提交
    • E
      net: avoid 32 x truesize under-estimation for tiny skbs · 2eaab298
      由 Eric Dumazet 提交于 
      stable inclusion
from stable-5.10.10
commit 024158d3b5715e830bf4b51c4452132937c8f1e8
bugzilla: 47610

--------------------------------

[ Upstream commit 3226b158 ]

Both virtio net and napi_get_frags() allocate skbs
with a very small skb->head

While using page fragments instead of a kmalloc backed skb->head might give
a small performance improvement in some cases, there is a huge risk of
under estimating memory usage.

For both GOOD_COPY_LEN and GRO_MAX_HEAD, we can fit at least 32 allocations
per page (order-3 page in x86), or even 64 on PowerPC

We have been tracking OOM issues on GKE hosts hitting tcp_mem limits
but consuming far more memory for TCP buffers than instructed in tcp_mem[2]

Even if we force napi_alloc_skb() to only use order-0 pages, the issue
would still be there on arches with PAGE_SIZE >= 32768

This patch makes sure that small skb head are kmalloc backed, so that
other objects in the slab page can be reused instead of being held as long
as skbs are sitting in socket queues.

Note that we might in the future use the sk_buff napi cache,
instead of going through a more expensive __alloc_skb()

Another idea would be to use separate page sizes depending
on the allocated length (to never have more than 4 frags per page)

I would like to thank Greg Thelen for his precious help on this matter,
analysing crash dumps is always a time consuming task.

Fixes: fd11a83d ("net: Pull out core bits of __netdev_alloc_skb and add __napi_alloc_skb")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Reviewed-by: NAlexander Duyck <alexanderduyck@fb.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20210113161819.1155526-1-eric.dumazet@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
      2eaab298
    • D
      net: fix use-after-free when UDP GRO with shared fraglist · da767576
      由 Dongseok Yi 提交于 
      stable inclusion
from stable-5.10.10
commit 24cd3317418955fd9489e4e7e9c2b643691b270b
bugzilla: 47610

--------------------------------

[ Upstream commit 53475c5d ]

skbs in fraglist could be shared by a BPF filter loaded at TC. If TC
writes, it will call skb_ensure_writable -> pskb_expand_head to create
a private linear section for the head_skb. And then call
skb_clone_fraglist -> skb_get on each skb in the fraglist.

skb_segment_list overwrites part of the skb linear section of each
fragment itself. Even after skb_clone, the frag_skbs share their
linear section with their clone in PF_PACKET.

Both sk_receive_queue of PF_PACKET and PF_INET (or PF_INET6) can have
a link for the same frag_skbs chain. If a new skb (not frags) is
queued to one of the sk_receive_queue, multiple ptypes can see and
release this. It causes use-after-free.

[ 4443.426215] ------------[ cut here ]------------
[ 4443.426222] refcount_t: underflow; use-after-free.
[ 4443.426291] WARNING: CPU: 7 PID: 28161 at lib/refcount.c:190
refcount_dec_and_test_checked+0xa4/0xc8
[ 4443.426726] pstate: 60400005 (nZCv daif +PAN -UAO)
[ 4443.426732] pc : refcount_dec_and_test_checked+0xa4/0xc8
[ 4443.426737] lr : refcount_dec_and_test_checked+0xa0/0xc8
[ 4443.426808] Call trace:
[ 4443.426813]  refcount_dec_and_test_checked+0xa4/0xc8
[ 4443.426823]  skb_release_data+0x144/0x264
[ 4443.426828]  kfree_skb+0x58/0xc4
[ 4443.426832]  skb_queue_purge+0x64/0x9c
[ 4443.426844]  packet_set_ring+0x5f0/0x820
[ 4443.426849]  packet_setsockopt+0x5a4/0xcd0
[ 4443.426853]  __sys_setsockopt+0x188/0x278
[ 4443.426858]  __arm64_sys_setsockopt+0x28/0x38
[ 4443.426869]  el0_svc_common+0xf0/0x1d0
[ 4443.426873]  el0_svc_handler+0x74/0x98
[ 4443.426880]  el0_svc+0x8/0xc

Fixes: 3a1296a3 (net: Support GRO/GSO fraglist chaining.)
Signed-off-by: NDongseok Yi <dseok.yi@samsung.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/1610072918-174177-1-git-send-email-dseok.yi@samsung.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
      da767576
  23. 27 1月, 2021 1 次提交
  25. 04 12月, 2020 1 次提交
  27. 28 11月, 2020 1 次提交
  29. 06 10月, 2020 1 次提交
  31. 05 10月, 2020 1 次提交
  33. 04 10月, 2020 1 次提交
    • G
      net/sched: act_vlan: Add {POP,PUSH}_ETH actions · 19fbcb36
      由 Guillaume Nault 提交于 
      Implement TCA_VLAN_ACT_POP_ETH and TCA_VLAN_ACT_PUSH_ETH, to
respectively pop and push a base Ethernet header at the beginning of a
frame.

POP_ETH is just a matter of pulling ETH_HLEN bytes. VLAN tags, if any,
must be stripped before calling POP_ETH.

PUSH_ETH is restricted to skbs with no mac_header, and only the MAC
addresses can be configured. The Ethertype is automatically set from
skb->protocol. These restrictions ensure that all skb's fields remain
consistent, so that this action can't confuse other part of the
networking stack (like GSO).

Since openvswitch already had these actions, consolidate the code in
skbuff.c (like for vlan and mpls push/pop).
Signed-off-by: NGuillaume Nault <gnault@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      19fbcb36
  35. 21 9月, 2020 1 次提交
  37. 25 8月, 2020 1 次提交
  39. 21 8月, 2020 2 次提交
  41. 19 8月, 2020 2 次提交
  43. 17 8月, 2020 1 次提交
  45. 09 8月, 2020 1 次提交
  47. 04 8月, 2020 2 次提交
  49. 01 8月, 2020 1 次提交
  51. 20 5月, 2020 1 次提交
  53. 18 5月, 2020 1 次提交
  55. 02 5月, 2020 1 次提交
  57. 31 3月, 2020 1 次提交
  59. 24 3月, 2020 1 次提交
    • Y
      net: Make skb_segment not to compute checksum if network controller supports checksumming · 1454c9fa
      由 Yadu Kishore 提交于 
      Problem:
TCP checksum in the output path is not being offloaded during GSO
in the following case:
The network driver does not support scatter-gather but supports
checksum offload with NETIF_F_HW_CSUM.

Cause:
skb_segment calls skb_copy_and_csum_bits if the network driver
does not announce NETIF_F_SG. It does not check if the driver
supports NETIF_F_HW_CSUM.
So for devices which might want to offload checksum but do not support SG
there is currently no way to do so if GSO is enabled.

Solution:
In skb_segment check if the network controller does checksum and if so
call skb_copy_bits instead of skb_copy_and_csum_bits.

Testing:
Without the patch, ran iperf TCP traffic with NETIF_F_HW_CSUM enabled
in the network driver. Observed the TCP checksum offload is not happening
since the skbs received by the driver in the output path have
skb->ip_summed set to CHECKSUM_NONE.

With the patch ran iperf TCP traffic and observed that TCP checksum
is being offloaded with skb->ip_summed set to CHECKSUM_PARTIAL.
Also tested with the patch by disabling NETIF_F_HW_CSUM in the driver
to cover the newly introduced if-else code path in skb_segment.

Link: https://lore.kernel.org/netdev/CA+FuTSeYGYr3Umij+Mezk9CUcaxYwqEe5sPSuXF8jPE2yMFJAw@mail.gmail.comSigned-off-by: NYadu Kishore <kyk.segfault@gmail.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1454c9fa