Commit graph

12 commits

Author SHA1 Message Date
Chengen Du
3c5432e67c net/sched: Fix UAF when resolving a clash
[ Upstream commit 26488172b0292bed837b95a006a3f3431d1898c3 ]

KASAN reports the following UAF:

 BUG: KASAN: slab-use-after-free in tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct]
 Read of size 1 at addr ffff888c07603600 by task handler130/6469

 Call Trace:
  <IRQ>
  dump_stack_lvl+0x48/0x70
  print_address_description.constprop.0+0x33/0x3d0
  print_report+0xc0/0x2b0
  kasan_report+0xd0/0x120
  __asan_load1+0x6c/0x80
  tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct]
  tcf_ct_act+0x886/0x1350 [act_ct]
  tcf_action_exec+0xf8/0x1f0
  fl_classify+0x355/0x360 [cls_flower]
  __tcf_classify+0x1fd/0x330
  tcf_classify+0x21c/0x3c0
  sch_handle_ingress.constprop.0+0x2c5/0x500
  __netif_receive_skb_core.constprop.0+0xb25/0x1510
  __netif_receive_skb_list_core+0x220/0x4c0
  netif_receive_skb_list_internal+0x446/0x620
  napi_complete_done+0x157/0x3d0
  gro_cell_poll+0xcf/0x100
  __napi_poll+0x65/0x310
  net_rx_action+0x30c/0x5c0
  __do_softirq+0x14f/0x491
  __irq_exit_rcu+0x82/0xc0
  irq_exit_rcu+0xe/0x20
  common_interrupt+0xa1/0xb0
  </IRQ>
  <TASK>
  asm_common_interrupt+0x27/0x40

 Allocated by task 6469:
  kasan_save_stack+0x38/0x70
  kasan_set_track+0x25/0x40
  kasan_save_alloc_info+0x1e/0x40
  __kasan_krealloc+0x133/0x190
  krealloc+0xaa/0x130
  nf_ct_ext_add+0xed/0x230 [nf_conntrack]
  tcf_ct_act+0x1095/0x1350 [act_ct]
  tcf_action_exec+0xf8/0x1f0
  fl_classify+0x355/0x360 [cls_flower]
  __tcf_classify+0x1fd/0x330
  tcf_classify+0x21c/0x3c0
  sch_handle_ingress.constprop.0+0x2c5/0x500
  __netif_receive_skb_core.constprop.0+0xb25/0x1510
  __netif_receive_skb_list_core+0x220/0x4c0
  netif_receive_skb_list_internal+0x446/0x620
  napi_complete_done+0x157/0x3d0
  gro_cell_poll+0xcf/0x100
  __napi_poll+0x65/0x310
  net_rx_action+0x30c/0x5c0
  __do_softirq+0x14f/0x491

 Freed by task 6469:
  kasan_save_stack+0x38/0x70
  kasan_set_track+0x25/0x40
  kasan_save_free_info+0x2b/0x60
  ____kasan_slab_free+0x180/0x1f0
  __kasan_slab_free+0x12/0x30
  slab_free_freelist_hook+0xd2/0x1a0
  __kmem_cache_free+0x1a2/0x2f0
  kfree+0x78/0x120
  nf_conntrack_free+0x74/0x130 [nf_conntrack]
  nf_ct_destroy+0xb2/0x140 [nf_conntrack]
  __nf_ct_resolve_clash+0x529/0x5d0 [nf_conntrack]
  nf_ct_resolve_clash+0xf6/0x490 [nf_conntrack]
  __nf_conntrack_confirm+0x2c6/0x770 [nf_conntrack]
  tcf_ct_act+0x12ad/0x1350 [act_ct]
  tcf_action_exec+0xf8/0x1f0
  fl_classify+0x355/0x360 [cls_flower]
  __tcf_classify+0x1fd/0x330
  tcf_classify+0x21c/0x3c0
  sch_handle_ingress.constprop.0+0x2c5/0x500
  __netif_receive_skb_core.constprop.0+0xb25/0x1510
  __netif_receive_skb_list_core+0x220/0x4c0
  netif_receive_skb_list_internal+0x446/0x620
  napi_complete_done+0x157/0x3d0
  gro_cell_poll+0xcf/0x100
  __napi_poll+0x65/0x310
  net_rx_action+0x30c/0x5c0
  __do_softirq+0x14f/0x491

The ct may be dropped if a clash has been resolved but is still passed to
the tcf_ct_flow_table_process_conn function for further usage. This issue
can be fixed by retrieving ct from skb again after confirming conntrack.

Fixes: 0cc254e5aa37 ("net/sched: act_ct: Offload connections with commit action")
Co-developed-by: Gerald Yang <gerald.yang@canonical.com>
Signed-off-by: Gerald Yang <gerald.yang@canonical.com>
Signed-off-by: Chengen Du <chengen.du@canonical.com>
Link: https://patch.msgid.link/20240710053747.13223-1-chengen.du@canonical.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 14:19:44 +01:00
Xin Long
c68d475c9b sched: act_ct: add netns into the key of tcf_ct_flow_table
[ Upstream commit 88c67aeb14070bab61d3dd8be96c8b42ebcaf53a ]

zones_ht is a global hashtable for flow_table with zone as key. However,
it does not consider netns when getting a flow_table from zones_ht in
tcf_ct_init(), and it means an act_ct action in netns A may get a
flow_table that belongs to netns B if it has the same zone value.

In Shuang's test with the TOPO:

  tcf2_c <---> tcf2_sw1 <---> tcf2_sw2 <---> tcf2_s

tcf2_sw1 and tcf2_sw2 saw the same flow and used the same flow table,
which caused their ct entries entering unexpected states and the
TCP connection not able to end normally.

This patch fixes the issue simply by adding netns into the key of
tcf_ct_flow_table so that an act_ct action gets a flow_table that
belongs to its own netns in tcf_ct_init().

Note that for easy coding we don't use tcf_ct_flow_table.nf_ft.net,
as the ct_ft is initialized after inserting it to the hashtable in
tcf_ct_flow_table_get() and also it requires to implement several
functions in rhashtable_params including hashfn, obj_hashfn and
obj_cmpfn.

Fixes: 64ff70b80fd4 ("net/sched: act_ct: Offload established connections to flow table")
Reported-by: Shuang Li <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/1db5b6cc6902c5fc6f8c6cbd85494a2008087be5.1718488050.git.lucien.xin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 14:19:08 +01:00
Vlad Buslov
fd1fe3a940 net/sched: act_ct: set 'net' pointer when creating new nf_flow_table
[ Upstream commit fc54d9065f90dd25063883f404e6ff9a76913e73 ]

Following patches in series use the pointer to access flow table offload
debug variables.

Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Oz Shlomo <ozsh@nvidia.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stable-dep-of: 88c67aeb1407 ("sched: act_ct: add netns into the key of tcf_ct_flow_table")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 14:19:08 +01:00
David Ruth
ccad0626e3 net/sched: act_api: fix possible infinite loop in tcf_idr_check_alloc()
[ Upstream commit d864319871b05fadd153e0aede4811ca7008f5d6 ]

syzbot found hanging tasks waiting on rtnl_lock [1]

A reproducer is available in the syzbot bug.

When a request to add multiple actions with the same index is sent, the
second request will block forever on the first request. This holds
rtnl_lock, and causes tasks to hang.

Return -EAGAIN to prevent infinite looping, while keeping documented
behavior.

[1]

INFO: task kworker/1:0:5088 blocked for more than 143 seconds.
Not tainted 6.9.0-rc4-syzkaller-00173-g3cdb45594619 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0 state:D stack:23744 pid:5088 tgid:5088 ppid:2 flags:0x00004000
Workqueue: events_power_efficient reg_check_chans_work
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5409 [inline]
__schedule+0xf15/0x5d00 kernel/sched/core.c:6746
__schedule_loop kernel/sched/core.c:6823 [inline]
schedule+0xe7/0x350 kernel/sched/core.c:6838
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895
__mutex_lock_common kernel/locking/mutex.c:684 [inline]
__mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752
wiphy_lock include/net/cfg80211.h:5953 [inline]
reg_leave_invalid_chans net/wireless/reg.c:2466 [inline]
reg_check_chans_work+0x10a/0x10e0 net/wireless/reg.c:2481

Fixes: 0190c1d452a9 ("net: sched: atomically check-allocate action")
Reported-by: syzbot+b87c222546179f4513a7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=b87c222546179f4513a7
Signed-off-by: David Ruth <druth@chromium.org>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20240614190326.1349786-1-druth@chromium.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 14:19:08 +01:00
Pedro Tammela
435b497428 net/sched: act_api: rely on rcu in tcf_idr_check_alloc
[ Upstream commit 4b55e86736d5b492cf689125da2600f59c7d2c39 ]

Instead of relying only on the idrinfo->lock mutex for
bind/alloc logic, rely on a combination of rcu + mutex + atomics
to better scale the case where multiple rtnl-less filters are
binding to the same action object.

Action binding happens when an action index is specified explicitly and
an action exists which such index exists. Example:
  tc actions add action drop index 1
  tc filter add ... matchall action drop index 1
  tc filter add ... matchall action drop index 1
  tc filter add ... matchall action drop index 1
  tc filter ls ...
     filter protocol all pref 49150 matchall chain 0 filter protocol all pref 49150 matchall chain 0 handle 0x1
     not_in_hw
           action order 1: gact action drop
            random type none pass val 0
            index 1 ref 4 bind 3

   filter protocol all pref 49151 matchall chain 0 filter protocol all pref 49151 matchall chain 0 handle 0x1
     not_in_hw
           action order 1: gact action drop
            random type none pass val 0
            index 1 ref 4 bind 3

   filter protocol all pref 49152 matchall chain 0 filter protocol all pref 49152 matchall chain 0 handle 0x1
     not_in_hw
           action order 1: gact action drop
            random type none pass val 0
            index 1 ref 4 bind 3

When no index is specified, as before, grab the mutex and allocate
in the idr the next available id. In this version, as opposed to before,
it's simplified to store the -EBUSY pointer instead of the previous
alloc + replace combination.

When an index is specified, rely on rcu to find if there's an object in
such index. If there's none, fallback to the above, serializing on the
mutex and reserving the specified id. If there's one, it can be an -EBUSY
pointer, in which case we just try again until it's an action, or an action.
Given the rcu guarantees, the action found could be dead and therefore
we need to bump the refcount if it's not 0, handling the case it's
in fact 0.

As bind and the action refcount are already atomics, these increments can
happen without the mutex protection while many tcf_idr_check_alloc race
to bind to the same action instance.

In case binding encounters a parallel delete or add, it will return
-EAGAIN in order to try again. Both filter and action apis already
have the retry machinery in-place. In case it's an unlocked filter it
retries under the rtnl lock.

Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Link: https://lore.kernel.org/r/20231211181807.96028-2-pctammela@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: d864319871b0 ("net/sched: act_api: fix possible infinite loop in tcf_idr_check_alloc()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 14:19:08 +01:00
Eric Dumazet
3cba57a6fb net/sched: taprio: always validate TCA_TAPRIO_ATTR_PRIOMAP
[ Upstream commit f921a58ae20852d188f70842431ce6519c4fdc36 ]

If one TCA_TAPRIO_ATTR_PRIOMAP attribute has been provided,
taprio_parse_mqprio_opt() must validate it, or userspace
can inject arbitrary data to the kernel, the second time
taprio_change() is called.

First call (with valid attributes) sets dev->num_tc
to a non zero value.

Second call (with arbitrary mqprio attributes)
returns early from taprio_parse_mqprio_opt()
and bad things can happen.

Fixes: a3d43c0d56f1 ("taprio: Add support adding an admin schedule")
Reported-by: Noam Rathaus <noamr@ssd-disclosure.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20240604181511.769870-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 14:19:01 +01:00
Hangyu Hua
cfe0c7acc2 net: sched: sch_multiq: fix possible OOB write in multiq_tune()
[ Upstream commit affc18fdc694190ca7575b9a86632a73b9fe043d ]

q->bands will be assigned to qopt->bands to execute subsequent code logic
after kmalloc. So the old q->bands should not be used in kmalloc.
Otherwise, an out-of-bounds write will occur.

Fixes: c2999f7fb05b ("net: sched: multiq: don't call qdisc_put() while holding tree lock")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Acked-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 14:19:00 +01:00
Eric Dumazet
66946c581b net/sched: act_skbmod: prevent kernel-infoleak
commit d313eb8b77557a6d5855f42d2234bd592c7b50dd upstream.

syzbot found that tcf_skbmod_dump() was copying four bytes
from kernel stack to user space [1].

The issue here is that 'struct tc_skbmod' has a four bytes hole.

We need to clear the structure before filling fields.

[1]
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
 BUG: KMSAN: kernel-infoleak in copy_to_user_iter lib/iov_iter.c:24 [inline]
 BUG: KMSAN: kernel-infoleak in iterate_ubuf include/linux/iov_iter.h:29 [inline]
 BUG: KMSAN: kernel-infoleak in iterate_and_advance2 include/linux/iov_iter.h:245 [inline]
 BUG: KMSAN: kernel-infoleak in iterate_and_advance include/linux/iov_iter.h:271 [inline]
 BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x366/0x2520 lib/iov_iter.c:185
  instrument_copy_to_user include/linux/instrumented.h:114 [inline]
  copy_to_user_iter lib/iov_iter.c:24 [inline]
  iterate_ubuf include/linux/iov_iter.h:29 [inline]
  iterate_and_advance2 include/linux/iov_iter.h:245 [inline]
  iterate_and_advance include/linux/iov_iter.h:271 [inline]
  _copy_to_iter+0x366/0x2520 lib/iov_iter.c:185
  copy_to_iter include/linux/uio.h:196 [inline]
  simple_copy_to_iter net/core/datagram.c:532 [inline]
  __skb_datagram_iter+0x185/0x1000 net/core/datagram.c:420
  skb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:546
  skb_copy_datagram_msg include/linux/skbuff.h:4050 [inline]
  netlink_recvmsg+0x432/0x1610 net/netlink/af_netlink.c:1962
  sock_recvmsg_nosec net/socket.c:1046 [inline]
  sock_recvmsg+0x2c4/0x340 net/socket.c:1068
  __sys_recvfrom+0x35a/0x5f0 net/socket.c:2242
  __do_sys_recvfrom net/socket.c:2260 [inline]
  __se_sys_recvfrom net/socket.c:2256 [inline]
  __x64_sys_recvfrom+0x126/0x1d0 net/socket.c:2256
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Uninit was stored to memory at:
  pskb_expand_head+0x30f/0x19d0 net/core/skbuff.c:2253
  netlink_trim+0x2c2/0x330 net/netlink/af_netlink.c:1317
  netlink_unicast+0x9f/0x1260 net/netlink/af_netlink.c:1351
  nlmsg_unicast include/net/netlink.h:1144 [inline]
  nlmsg_notify+0x21d/0x2f0 net/netlink/af_netlink.c:2610
  rtnetlink_send+0x73/0x90 net/core/rtnetlink.c:741
  rtnetlink_maybe_send include/linux/rtnetlink.h:17 [inline]
  tcf_add_notify net/sched/act_api.c:2048 [inline]
  tcf_action_add net/sched/act_api.c:2071 [inline]
  tc_ctl_action+0x146e/0x19d0 net/sched/act_api.c:2119
  rtnetlink_rcv_msg+0x1737/0x1900 net/core/rtnetlink.c:6595
  netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2559
  rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6613
  netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
  netlink_unicast+0xf4c/0x1260 net/netlink/af_netlink.c:1361
  netlink_sendmsg+0x10df/0x11f0 net/netlink/af_netlink.c:1905
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x30f/0x380 net/socket.c:745
  ____sys_sendmsg+0x877/0xb60 net/socket.c:2584
  ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638
  __sys_sendmsg net/socket.c:2667 [inline]
  __do_sys_sendmsg net/socket.c:2676 [inline]
  __se_sys_sendmsg net/socket.c:2674 [inline]
  __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2674
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Uninit was stored to memory at:
  __nla_put lib/nlattr.c:1041 [inline]
  nla_put+0x1c6/0x230 lib/nlattr.c:1099
  tcf_skbmod_dump+0x23f/0xc20 net/sched/act_skbmod.c:256
  tcf_action_dump_old net/sched/act_api.c:1191 [inline]
  tcf_action_dump_1+0x85e/0x970 net/sched/act_api.c:1227
  tcf_action_dump+0x1fd/0x460 net/sched/act_api.c:1251
  tca_get_fill+0x519/0x7a0 net/sched/act_api.c:1628
  tcf_add_notify_msg net/sched/act_api.c:2023 [inline]
  tcf_add_notify net/sched/act_api.c:2042 [inline]
  tcf_action_add net/sched/act_api.c:2071 [inline]
  tc_ctl_action+0x1365/0x19d0 net/sched/act_api.c:2119
  rtnetlink_rcv_msg+0x1737/0x1900 net/core/rtnetlink.c:6595
  netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2559
  rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6613
  netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
  netlink_unicast+0xf4c/0x1260 net/netlink/af_netlink.c:1361
  netlink_sendmsg+0x10df/0x11f0 net/netlink/af_netlink.c:1905
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x30f/0x380 net/socket.c:745
  ____sys_sendmsg+0x877/0xb60 net/socket.c:2584
  ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638
  __sys_sendmsg net/socket.c:2667 [inline]
  __do_sys_sendmsg net/socket.c:2676 [inline]
  __se_sys_sendmsg net/socket.c:2674 [inline]
  __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2674
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Local variable opt created at:
  tcf_skbmod_dump+0x9d/0xc20 net/sched/act_skbmod.c:244
  tcf_action_dump_old net/sched/act_api.c:1191 [inline]
  tcf_action_dump_1+0x85e/0x970 net/sched/act_api.c:1227

Bytes 188-191 of 248 are uninitialized
Memory access of size 248 starts at ffff888117697680
Data copied to user address 00007ffe56d855f0

Fixes: 86da71b57383 ("net_sched: Introduce skbmod action")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20240403130908.93421-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-19 09:22:46 +01:00
Hangyu Hua
b973fdb591 net: sched: em_text: fix possible memory leak in em_text_destroy()
[ Upstream commit 8fcb0382af6f1ef50936f1be05b8149eb2f88496 ]

m->data needs to be freed when em_text_destroy is called.

Fixes: d675c989ed2d ("[PKT_SCHED]: Packet classification based on textsearch (ematch)")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 12:12:06 +01:00
Gustavo A. R. Silva
7c305720ca net: sched: cls_u32: Fix allocation size in u32_init()
[ Upstream commit c4d49196ceec80e30e8d981410d73331b49b7850 ]

commit d61491a51f7e ("net/sched: cls_u32: Replace one-element array
with flexible-array member") incorrecly replaced an instance of
`sizeof(*tp_c)` with `struct_size(tp_c, hlist->ht, 1)`. This results
in a an over-allocation of 8 bytes.

This change is wrong because `hlist` in `struct tc_u_common` is a
pointer:

net/sched/cls_u32.c:
struct tc_u_common {
        struct tc_u_hnode __rcu *hlist;
        void                    *ptr;
        int                     refcnt;
        struct idr              handle_idr;
        struct hlist_node       hnode;
        long                    knodes;
};

So, the use of `struct_size()` makes no sense: we don't need to allocate
any extra space for a flexible-array member. `sizeof(*tp_c)` is just fine.

So, `struct_size(tp_c, hlist->ht, 1)` translates to:

sizeof(*tp_c) + sizeof(tp_c->hlist->ht) ==
sizeof(struct tc_u_common) + sizeof(struct tc_u_knode *) ==
						144 + 8  == 0x98 (byes)
						     ^^^
						      |
						unnecessary extra
						allocation size

$ pahole -C tc_u_common net/sched/cls_u32.o
struct tc_u_common {
	struct tc_u_hnode *        hlist;                /*     0     8 */
	void *                     ptr;                  /*     8     8 */
	int                        refcnt;               /*    16     4 */

	/* XXX 4 bytes hole, try to pack */

	struct idr                 handle_idr;           /*    24    96 */
	/* --- cacheline 1 boundary (64 bytes) was 56 bytes ago --- */
	struct hlist_node          hnode;                /*   120    16 */
	/* --- cacheline 2 boundary (128 bytes) was 8 bytes ago --- */
	long int                   knodes;               /*   136     8 */

	/* size: 144, cachelines: 3, members: 6 */
	/* sum members: 140, holes: 1, sum holes: 4 */
	/* last cacheline: 16 bytes */
};

And with `sizeof(*tp_c)`, we have:

	sizeof(*tp_c) == sizeof(struct tc_u_common) == 144 == 0x90 (bytes)

which is the correct and original allocation size.

Fix this issue by replacing `struct_size(tp_c, hlist->ht, 1)` with
`sizeof(*tp_c)`, and avoid allocating 8 too many bytes.

The following difference in binary output is expected and reflects the
desired change:

| net/sched/cls_u32.o
| @@ -6148,7 +6148,7 @@
| include/linux/slab.h:599
|     2cf5:      mov    0x0(%rip),%rdi        # 2cfc <u32_init+0xfc>
|                        2cf8: R_X86_64_PC32     kmalloc_caches+0xc
|-    2cfc:      mov    $0x98,%edx
|+    2cfc:      mov    $0x90,%edx

Reported-by: Alejandro Colomar <alx@kernel.org>
Closes: https://lore.kernel.org/lkml/09b4a2ce-da74-3a19-6961-67883f634d98@kernel.org/
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 10:58:46 +01:00
Pedro Tammela
9880dd211f net/sched: sch_hfsc: upgrade 'rt' to 'sc' when it becomes a inner curve
commit a13b67c9a015c4e21601ef9aa4ec9c5d972df1b4 upstream.

Christian Theune says:
   I upgraded from 6.1.38 to 6.1.55 this morning and it broke my traffic shaping script,
   leaving me with a non-functional uplink on a remote router.

A 'rt' curve cannot be used as a inner curve (parent class), but we were
allowing such configurations since the qdisc was introduced. Such
configurations would trigger a UAF as Budimir explains:
   The parent will have vttree_insert() called on it in init_vf(),
   but will not have vttree_remove() called on it in update_vf()
   because it does not have the HFSC_FSC flag set.

The qdisc always assumes that inner classes have the HFSC_FSC flag set.
This is by design as it doesn't make sense 'qdisc wise' for an 'rt'
curve to be an inner curve.

Budimir's original patch disallows users to add classes with a 'rt'
parent, but this is too strict as it breaks users that have been using
'rt' as a inner class. Another approach, taken by this patch, is to
upgrade the inner 'rt' into a 'sc', warning the user in the process.
It avoids the UAF reported by Budimir while also being more permissive
to bad scripts/users/code using 'rt' as a inner class.

Users checking the `tc class ls [...]` or `tc class get [...]` dumps would
observe the curve change and are potentially breaking with this change.

v1->v2: https://lore.kernel.org/all/20231013151057.2611860-1-pctammela@mojatatu.com/
- Correct 'Fixes' tag and merge with revert (Jakub)

Cc: Christian Theune <ct@flyingcircus.io>
Cc: Budimir Markovic <markovicbudimir@gmail.com>
Fixes: b3d26c5702c7 ("net/sched: sch_hfsc: Ensure inner classes have fsc curve")
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20231017143602.3191556-1-pctammela@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-08 11:26:11 +01:00
Gabriel2392
7ed7ee9edf Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00