linux-stable.git/net/sched, branch v6.8 Linux kernel stable tree net/sched: flower: Add lock protection when remove filter handle 2024-02-22T01:12:03+00:00 Jianbo Liu jianbol@nvidia.com 2024-02-20T08:59:28+00:00 1fde0ca3a0de7e9f917668941156959dd5e9108b As IDR can't protect itself from the concurrent modification, place idr_remove() under the protection of tp->lock. Fixes: 08a0063df3ae ("net/sched: flower: Move filter handle initialization earlier") Signed-off-by: Jianbo Liu <jianbol@nvidia.com> Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com> Reviewed-by: Gal Pressman <gal@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://lore.kernel.org/r/20240220085928.9161-1-jianbol@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
As IDR can't protect itself from the concurrent modification, place
idr_remove() under the protection of tp->lock.

Fixes: 08a0063df3ae ("net/sched: flower: Move filter handle initialization earlier")
Signed-off-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20240220085928.9161-1-jianbol@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/sched: act_mirred: don't override retval if we already lost the skb 2024-02-16T10:13:31+00:00 Jakub Kicinski kuba@kernel.org 2024-02-15T14:33:46+00:00 166c2c8a6a4dc2e4ceba9e10cfe81c3e469e3210 If we're redirecting the skb, and haven't called tcf_mirred_forward(), yet, we need to tell the core to drop the skb by setting the retcode to SHOT. If we have called tcf_mirred_forward(), however, the skb is out of our hands and returning SHOT will lead to UaF. Move the retval override to the error path which actually need it. Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com> Fixes: e5cf1baf92cb ("act_mirred: use TC_ACT_REINSERT when possible") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
If we're redirecting the skb, and haven't called tcf_mirred_forward(),
yet, we need to tell the core to drop the skb by setting the retcode
to SHOT. If we have called tcf_mirred_forward(), however, the skb
is out of our hands and returning SHOT will lead to UaF.

Move the retval override to the error path which actually need it.

Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Fixes: e5cf1baf92cb ("act_mirred: use TC_ACT_REINSERT when possible")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/sched: act_mirred: use the backlog for mirred ingress 2024-02-16T10:13:31+00:00 Jakub Kicinski kuba@kernel.org 2024-02-15T14:33:45+00:00 52f671db18823089a02f07efc04efdb2272ddc17 The test Davide added in commit ca22da2fbd69 ("act_mirred: use the backlog for nested calls to mirred ingress") hangs our testing VMs every 10 or so runs, with the familiar tcp_v4_rcv -> tcp_v4_rcv deadlock reported by lockdep. The problem as previously described by Davide (see Link) is that if we reverse flow of traffic with the redirect (egress -> ingress) we may reach the same socket which generated the packet. And we may still be holding its socket lock. The common solution to such deadlocks is to put the packet in the Rx backlog, rather than run the Rx path inline. Do that for all egress -> ingress reversals, not just once we started to nest mirred calls. In the past there was a concern that the backlog indirection will lead to loss of error reporting / less accurate stats. But the current workaround does not seem to address the issue. Fixes: 53592b364001 ("net/sched: act_mirred: Implement ingress actions") Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Suggested-by: Davide Caratti <dcaratti@redhat.com> Link: https://lore.kernel.org/netdev/33dc43f587ec1388ba456b4915c75f02a8aae226.1663945716.git.dcaratti@redhat.com/ Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The test Davide added in commit ca22da2fbd69 ("act_mirred: use the backlog
for nested calls to mirred ingress") hangs our testing VMs every 10 or so
runs, with the familiar tcp_v4_rcv -> tcp_v4_rcv deadlock reported by
lockdep.

The problem as previously described by Davide (see Link) is that
if we reverse flow of traffic with the redirect (egress -> ingress)
we may reach the same socket which generated the packet. And we may
still be holding its socket lock. The common solution to such deadlocks
is to put the packet in the Rx backlog, rather than run the Rx path
inline. Do that for all egress -> ingress reversals, not just once
we started to nest mirred calls.

In the past there was a concern that the backlog indirection will
lead to loss of error reporting / less accurate stats. But the current
workaround does not seem to address the issue.

Fixes: 53592b364001 ("net/sched: act_mirred: Implement ingress actions")
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Suggested-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/netdev/33dc43f587ec1388ba456b4915c75f02a8aae226.1663945716.git.dcaratti@redhat.com/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fill in MODULE_DESCRIPTION()s for net/sched 2024-02-09T22:12:02+00:00 Breno Leitao leitao@debian.org 2024-02-08T16:42:42+00:00 a46c31bf2744b9807ba5e3ac8fdae2368d8bb3fa W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Add descriptions to the network schedulers. Suggested-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://lore.kernel.org/r/20240208164244.3818498-8-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the network schedulers.

Suggested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20240208164244.3818498-8-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/sched: act_mirred: Don't zero blockid when net device is being deleted 2024-02-09T20:57:25+00:00 Victor Nogueira victor@mojatatu.com 2024-02-07T22:29:02+00:00 aae09a6c7783e28d1bcafee85e172fe411923b22 While testing tdc with parallel tests for mirred to block we caught an intermittent bug. The blockid was being zeroed out when a net device was deleted and, thus, giving us an incorrect blockid value whenever we tried to dump the mirred action. Since we don't increment the block refcount in the control path (and only use the ID), we don't need to zero the blockid field whenever a net device is going down. Fixes: 42f39036cda8 ("net/sched: act_mirred: Allow mirred to block") Signed-off-by: Victor Nogueira <victor@mojatatu.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://lore.kernel.org/r/20240207222902.1469398-1-victor@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
While testing tdc with parallel tests for mirred to block we caught an
intermittent bug. The blockid was being zeroed out when a net device
was deleted and, thus, giving us an incorrect blockid value whenever
we tried to dump the mirred action. Since we don't increment the block
refcount in the control path (and only use the ID), we don't need to
zero the blockid field whenever a net device is going down.

Fixes: 42f39036cda8 ("net/sched: act_mirred: Allow mirred to block")
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20240207222902.1469398-1-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/sched: flower: Fix chain template offload 2024-01-24T01:33:59+00:00 Ido Schimmel idosch@nvidia.com 2024-01-22T13:28:43+00:00 32f2a0afa95fae0d1ceec2ff06e0e816939964b8 When a qdisc is deleted from a net device the stack instructs the underlying driver to remove its flow offload callback from the associated filter block using the 'FLOW_BLOCK_UNBIND' command. The stack then continues to replay the removal of the filters in the block for this driver by iterating over the chains in the block and invoking the 'reoffload' operation of the classifier being used. In turn, the classifier in its 'reoffload' operation prepares and emits a 'FLOW_CLS_DESTROY' command for each filter. However, the stack does not do the same for chain templates and the underlying driver never receives a 'FLOW_CLS_TMPLT_DESTROY' command when a qdisc is deleted. This results in a memory leak [1] which can be reproduced using [2]. Fix by introducing a 'tmplt_reoffload' operation and have the stack invoke it with the appropriate arguments as part of the replay. Implement the operation in the sole classifier that supports chain templates (flower) by emitting the 'FLOW_CLS_TMPLT_{CREATE,DESTROY}' command based on whether a flow offload callback is being bound to a filter block or being unbound from one. As far as I can tell, the issue happens since cited commit which reordered tcf_block_offload_unbind() before tcf_block_flush_all_chains() in __tcf_block_put(). The order cannot be reversed as the filter block is expected to be freed after flushing all the chains. [1] unreferenced object 0xffff888107e28800 (size 2048): comm "tc", pid 1079, jiffies 4294958525 (age 3074.287s) hex dump (first 32 bytes): b1 a6 7c 11 81 88 ff ff e0 5b b3 10 81 88 ff ff ..|......[...... 01 00 00 00 00 00 00 00 e0 aa b0 84 ff ff ff ff ................ backtrace: [<ffffffff81c06a68>] __kmem_cache_alloc_node+0x1e8/0x320 [<ffffffff81ab374e>] __kmalloc+0x4e/0x90 [<ffffffff832aec6d>] mlxsw_sp_acl_ruleset_get+0x34d/0x7a0 [<ffffffff832bc195>] mlxsw_sp_flower_tmplt_create+0x145/0x180 [<ffffffff832b2e1a>] mlxsw_sp_flow_block_cb+0x1ea/0x280 [<ffffffff83a10613>] tc_setup_cb_call+0x183/0x340 [<ffffffff83a9f85a>] fl_tmplt_create+0x3da/0x4c0 [<ffffffff83a22435>] tc_ctl_chain+0xa15/0x1170 [<ffffffff838a863c>] rtnetlink_rcv_msg+0x3cc/0xed0 [<ffffffff83ac87f0>] netlink_rcv_skb+0x170/0x440 [<ffffffff83ac6270>] netlink_unicast+0x540/0x820 [<ffffffff83ac6e28>] netlink_sendmsg+0x8d8/0xda0 [<ffffffff83793def>] ____sys_sendmsg+0x30f/0xa80 [<ffffffff8379d29a>] ___sys_sendmsg+0x13a/0x1e0 [<ffffffff8379d50c>] __sys_sendmsg+0x11c/0x1f0 [<ffffffff843b9ce0>] do_syscall_64+0x40/0xe0 unreferenced object 0xffff88816d2c0400 (size 1024): comm "tc", pid 1079, jiffies 4294958525 (age 3074.287s) hex dump (first 32 bytes): 40 00 00 00 00 00 00 00 57 f6 38 be 00 00 00 00 @.......W.8..... 10 04 2c 6d 81 88 ff ff 10 04 2c 6d 81 88 ff ff ..,m......,m.... backtrace: [<ffffffff81c06a68>] __kmem_cache_alloc_node+0x1e8/0x320 [<ffffffff81ab36c1>] __kmalloc_node+0x51/0x90 [<ffffffff81a8ed96>] kvmalloc_node+0xa6/0x1f0 [<ffffffff82827d03>] bucket_table_alloc.isra.0+0x83/0x460 [<ffffffff82828d2b>] rhashtable_init+0x43b/0x7c0 [<ffffffff832aed48>] mlxsw_sp_acl_ruleset_get+0x428/0x7a0 [<ffffffff832bc195>] mlxsw_sp_flower_tmplt_create+0x145/0x180 [<ffffffff832b2e1a>] mlxsw_sp_flow_block_cb+0x1ea/0x280 [<ffffffff83a10613>] tc_setup_cb_call+0x183/0x340 [<ffffffff83a9f85a>] fl_tmplt_create+0x3da/0x4c0 [<ffffffff83a22435>] tc_ctl_chain+0xa15/0x1170 [<ffffffff838a863c>] rtnetlink_rcv_msg+0x3cc/0xed0 [<ffffffff83ac87f0>] netlink_rcv_skb+0x170/0x440 [<ffffffff83ac6270>] netlink_unicast+0x540/0x820 [<ffffffff83ac6e28>] netlink_sendmsg+0x8d8/0xda0 [<ffffffff83793def>] ____sys_sendmsg+0x30f/0xa80 [2] # tc qdisc add dev swp1 clsact # tc chain add dev swp1 ingress proto ip chain 1 flower dst_ip 0.0.0.0/32 # tc qdisc del dev swp1 clsact # devlink dev reload pci/0000:06:00.0 Fixes: bbf73830cd48 ("net: sched: traverse chains in block with tcf_get_next_chain()") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
When a qdisc is deleted from a net device the stack instructs the
underlying driver to remove its flow offload callback from the
associated filter block using the 'FLOW_BLOCK_UNBIND' command. The stack
then continues to replay the removal of the filters in the block for
this driver by iterating over the chains in the block and invoking the
'reoffload' operation of the classifier being used. In turn, the
classifier in its 'reoffload' operation prepares and emits a
'FLOW_CLS_DESTROY' command for each filter.

However, the stack does not do the same for chain templates and the
underlying driver never receives a 'FLOW_CLS_TMPLT_DESTROY' command when
a qdisc is deleted. This results in a memory leak [1] which can be
reproduced using [2].

Fix by introducing a 'tmplt_reoffload' operation and have the stack
invoke it with the appropriate arguments as part of the replay.
Implement the operation in the sole classifier that supports chain
templates (flower) by emitting the 'FLOW_CLS_TMPLT_{CREATE,DESTROY}'
command based on whether a flow offload callback is being bound to a
filter block or being unbound from one.

As far as I can tell, the issue happens since cited commit which
reordered tcf_block_offload_unbind() before tcf_block_flush_all_chains()
in __tcf_block_put(). The order cannot be reversed as the filter block
is expected to be freed after flushing all the chains.

[1]
unreferenced object 0xffff888107e28800 (size 2048):
  comm "tc", pid 1079, jiffies 4294958525 (age 3074.287s)
  hex dump (first 32 bytes):
    b1 a6 7c 11 81 88 ff ff e0 5b b3 10 81 88 ff ff  ..|......[......
    01 00 00 00 00 00 00 00 e0 aa b0 84 ff ff ff ff  ................
  backtrace:
    [<ffffffff81c06a68>] __kmem_cache_alloc_node+0x1e8/0x320
    [<ffffffff81ab374e>] __kmalloc+0x4e/0x90
    [<ffffffff832aec6d>] mlxsw_sp_acl_ruleset_get+0x34d/0x7a0
    [<ffffffff832bc195>] mlxsw_sp_flower_tmplt_create+0x145/0x180
    [<ffffffff832b2e1a>] mlxsw_sp_flow_block_cb+0x1ea/0x280
    [<ffffffff83a10613>] tc_setup_cb_call+0x183/0x340
    [<ffffffff83a9f85a>] fl_tmplt_create+0x3da/0x4c0
    [<ffffffff83a22435>] tc_ctl_chain+0xa15/0x1170
    [<ffffffff838a863c>] rtnetlink_rcv_msg+0x3cc/0xed0
    [<ffffffff83ac87f0>] netlink_rcv_skb+0x170/0x440
    [<ffffffff83ac6270>] netlink_unicast+0x540/0x820
    [<ffffffff83ac6e28>] netlink_sendmsg+0x8d8/0xda0
    [<ffffffff83793def>] ____sys_sendmsg+0x30f/0xa80
    [<ffffffff8379d29a>] ___sys_sendmsg+0x13a/0x1e0
    [<ffffffff8379d50c>] __sys_sendmsg+0x11c/0x1f0
    [<ffffffff843b9ce0>] do_syscall_64+0x40/0xe0
unreferenced object 0xffff88816d2c0400 (size 1024):
  comm "tc", pid 1079, jiffies 4294958525 (age 3074.287s)
  hex dump (first 32 bytes):
    40 00 00 00 00 00 00 00 57 f6 38 be 00 00 00 00  @.......W.8.....
    10 04 2c 6d 81 88 ff ff 10 04 2c 6d 81 88 ff ff  ..,m......,m....
  backtrace:
    [<ffffffff81c06a68>] __kmem_cache_alloc_node+0x1e8/0x320
    [<ffffffff81ab36c1>] __kmalloc_node+0x51/0x90
    [<ffffffff81a8ed96>] kvmalloc_node+0xa6/0x1f0
    [<ffffffff82827d03>] bucket_table_alloc.isra.0+0x83/0x460
    [<ffffffff82828d2b>] rhashtable_init+0x43b/0x7c0
    [<ffffffff832aed48>] mlxsw_sp_acl_ruleset_get+0x428/0x7a0
    [<ffffffff832bc195>] mlxsw_sp_flower_tmplt_create+0x145/0x180
    [<ffffffff832b2e1a>] mlxsw_sp_flow_block_cb+0x1ea/0x280
    [<ffffffff83a10613>] tc_setup_cb_call+0x183/0x340
    [<ffffffff83a9f85a>] fl_tmplt_create+0x3da/0x4c0
    [<ffffffff83a22435>] tc_ctl_chain+0xa15/0x1170
    [<ffffffff838a863c>] rtnetlink_rcv_msg+0x3cc/0xed0
    [<ffffffff83ac87f0>] netlink_rcv_skb+0x170/0x440
    [<ffffffff83ac6270>] netlink_unicast+0x540/0x820
    [<ffffffff83ac6e28>] netlink_sendmsg+0x8d8/0xda0
    [<ffffffff83793def>] ____sys_sendmsg+0x30f/0xa80

[2]
 # tc qdisc add dev swp1 clsact
 # tc chain add dev swp1 ingress proto ip chain 1 flower dst_ip 0.0.0.0/32
 # tc qdisc del dev swp1 clsact
 # devlink dev reload pci/0000:06:00.0

Fixes: bbf73830cd48 ("net: sched: traverse chains in block with tcf_get_next_chain()")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: sched: track device in tcf_block_get/put_ext() only for clsact binder types 2024-01-13T15:49:15+00:00 Jiri Pirko jiri@nvidia.com 2024-01-12T11:39:30+00:00 e18405d0be8001fa4c5f9e61471f6ffd59c7a1b3 Clsact/ingress qdisc is not the only one using shared block, red is also using it. The device tracking was originally introduced by commit 913b47d3424e ("net/sched: Introduce tc block netdev tracking infra") for clsact/ingress only. Commit 94e2557d086a ("net: sched: move block device tracking into tcf_block_get/put_ext()") mistakenly enabled that for red as well. Fix that by adding a check for the binder type being clsact when adding device to the block->ports xarray. Reported-by: Ido Schimmel <idosch@idosch.org> Closes: https://lore.kernel.org/all/ZZ6JE0odnu1lLPtu@shredder/ Fixes: 94e2557d086a ("net: sched: move block device tracking into tcf_block_get/put_ext()") Signed-off-by: Jiri Pirko <jiri@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Tested-by: Victor Nogueira <victor@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Clsact/ingress qdisc is not the only one using shared block,
red is also using it. The device tracking was originally introduced
by commit 913b47d3424e ("net/sched: Introduce tc block netdev
tracking infra") for clsact/ingress only. Commit 94e2557d086a ("net:
sched: move block device tracking into tcf_block_get/put_ext()")
mistakenly enabled that for red as well.

Fix that by adding a check for the binder type being clsact when adding
device to the block->ports xarray.

Reported-by: Ido Schimmel <idosch@idosch.org>
Closes: https://lore.kernel.org/all/ZZ6JE0odnu1lLPtu@shredder/
Fixes: 94e2557d086a ("net: sched: move block device tracking into tcf_block_get/put_ext()")
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Tested-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-01-09T15:23:26+00:00 Paolo Abeni pabeni@redhat.com 2024-01-09T11:42:00+00:00 a7fe0881d9b78d402bbd9067dd4503a57c57a1d9 Merge in late fixes to prepare for the 6.8 net-next PR No conflicts. Signed-off-by: Paolo Abeni <pabeni@redhat.com> 
Merge in late fixes to prepare for the 6.8 net-next PR

No conflicts.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
net/sched: simplify tc_action_load_ops parameters 2024-01-07T14:58:26+00:00 Pedro Tammela pctammela@mojatatu.com 2024-01-05T00:38:10+00:00 405cd9fc6f44f7a54505019bea60de83f1c58365 Instead of using two bools derived from a flags passed as arguments to the parent function of tc_action_load_ops, just pass the flags itself to tc_action_load_ops to simplify its parameters. Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Instead of using two bools derived from a flags passed as arguments to
the parent function of tc_action_load_ops, just pass the flags itself
to tc_action_load_ops to simplify its parameters.

Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/sched: act_ct: fix skb leak and crash on ooo frags 2024-01-05T16:08:24+00:00 Tao Liu taoliu828@163.com 2023-12-28T08:14:57+00:00 3f14b377d01d8357eba032b4cabc8c1149b458b6 act_ct adds skb->users before defragmentation. If frags arrive in order, the last frag's reference is reset in: inet_frag_reasm_prepare skb_morph which is not straightforward. However when frags arrive out of order, nobody unref the last frag, and all frags are leaked. The situation is even worse, as initiating packet capture can lead to a crash[0] when skb has been cloned and shared at the same time. Fix the issue by removing skb_get() before defragmentation. act_ct returns TC_ACT_CONSUMED when defrag failed or in progress. [0]: [ 843.804823] ------------[ cut here ]------------ [ 843.809659] kernel BUG at net/core/skbuff.c:2091! [ 843.814516] invalid opcode: 0000 [#1] PREEMPT SMP [ 843.819296] CPU: 7 PID: 0 Comm: swapper/7 Kdump: loaded Tainted: G S 6.7.0-rc3 #2 [ 843.824107] Hardware name: XFUSION 1288H V6/BC13MBSBD, BIOS 1.29 11/25/2022 [ 843.828953] RIP: 0010:pskb_expand_head+0x2ac/0x300 [ 843.833805] Code: 8b 70 28 48 85 f6 74 82 48 83 c6 08 bf 01 00 00 00 e8 38 bd ff ff 8b 83 c0 00 00 00 48 03 83 c8 00 00 00 e9 62 ff ff ff 0f 0b <0f> 0b e8 8d d0 ff ff e9 b3 fd ff ff 81 7c 24 14 40 01 00 00 4c 89 [ 843.843698] RSP: 0018:ffffc9000cce07c0 EFLAGS: 00010202 [ 843.848524] RAX: 0000000000000002 RBX: ffff88811a211d00 RCX: 0000000000000820 [ 843.853299] RDX: 0000000000000640 RSI: 0000000000000000 RDI: ffff88811a211d00 [ 843.857974] RBP: ffff888127d39518 R08: 00000000bee97314 R09: 0000000000000000 [ 843.862584] R10: 0000000000000000 R11: ffff8881109f0000 R12: 0000000000000880 [ 843.867147] R13: ffff888127d39580 R14: 0000000000000640 R15: ffff888170f7b900 [ 843.871680] FS: 0000000000000000(0000) GS:ffff889ffffc0000(0000) knlGS:0000000000000000 [ 843.876242] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 843.880778] CR2: 00007fa42affcfb8 CR3: 000000011433a002 CR4: 0000000000770ef0 [ 843.885336] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 843.889809] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 843.894229] PKRU: 55555554 [ 843.898539] Call Trace: [ 843.902772] <IRQ> [ 843.906922] ? __die_body+0x1e/0x60 [ 843.911032] ? die+0x3c/0x60 [ 843.915037] ? do_trap+0xe2/0x110 [ 843.918911] ? pskb_expand_head+0x2ac/0x300 [ 843.922687] ? do_error_trap+0x65/0x80 [ 843.926342] ? pskb_expand_head+0x2ac/0x300 [ 843.929905] ? exc_invalid_op+0x50/0x60 [ 843.933398] ? pskb_expand_head+0x2ac/0x300 [ 843.936835] ? asm_exc_invalid_op+0x1a/0x20 [ 843.940226] ? pskb_expand_head+0x2ac/0x300 [ 843.943580] inet_frag_reasm_prepare+0xd1/0x240 [ 843.946904] ip_defrag+0x5d4/0x870 [ 843.950132] nf_ct_handle_fragments+0xec/0x130 [nf_conntrack] [ 843.953334] tcf_ct_act+0x252/0xd90 [act_ct] [ 843.956473] ? tcf_mirred_act+0x516/0x5a0 [act_mirred] [ 843.959657] tcf_action_exec+0xa1/0x160 [ 843.962823] fl_classify+0x1db/0x1f0 [cls_flower] [ 843.966010] ? skb_clone+0x53/0xc0 [ 843.969173] tcf_classify+0x24d/0x420 [ 843.972333] tc_run+0x8f/0xf0 [ 843.975465] __netif_receive_skb_core+0x67a/0x1080 [ 843.978634] ? dev_gro_receive+0x249/0x730 [ 843.981759] __netif_receive_skb_list_core+0x12d/0x260 [ 843.984869] netif_receive_skb_list_internal+0x1cb/0x2f0 [ 843.987957] ? mlx5e_handle_rx_cqe_mpwrq_rep+0xfa/0x1a0 [mlx5_core] [ 843.991170] napi_complete_done+0x72/0x1a0 [ 843.994305] mlx5e_napi_poll+0x28c/0x6d0 [mlx5_core] [ 843.997501] __napi_poll+0x25/0x1b0 [ 844.000627] net_rx_action+0x256/0x330 [ 844.003705] __do_softirq+0xb3/0x29b [ 844.006718] irq_exit_rcu+0x9e/0xc0 [ 844.009672] common_interrupt+0x86/0xa0 [ 844.012537] </IRQ> [ 844.015285] <TASK> [ 844.017937] asm_common_interrupt+0x26/0x40 [ 844.020591] RIP: 0010:acpi_safe_halt+0x1b/0x20 [ 844.023247] Code: ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 65 48 8b 04 25 00 18 03 00 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 81 d0 44 00 fb f4 <fa> c3 0f 1f 00 89 fa ec 48 8b 05 ee 88 ed 00 a9 00 00 00 80 75 11 [ 844.028900] RSP: 0018:ffffc90000533e70 EFLAGS: 00000246 [ 844.031725] RAX: 0000000000004000 RBX: 0000000000000001 RCX: 0000000000000000 [ 844.034553] RDX: ffff889ffffc0000 RSI: ffffffff828b7f20 RDI: ffff88a090f45c64 [ 844.037368] RBP: ffff88a0901a2800 R08: ffff88a090f45c00 R09: 00000000000317c0 [ 844.040155] R10: 00ec812281150475 R11: ffff889fffff0e04 R12: ffffffff828b7fa0 [ 844.042962] R13: ffffffff828b7f20 R14: 0000000000000001 R15: 0000000000000000 [ 844.045819] acpi_idle_enter+0x7b/0xc0 [ 844.048621] cpuidle_enter_state+0x7f/0x430 [ 844.051451] cpuidle_enter+0x2d/0x40 [ 844.054279] do_idle+0x1d4/0x240 [ 844.057096] cpu_startup_entry+0x2a/0x30 [ 844.059934] start_secondary+0x104/0x130 [ 844.062787] secondary_startup_64_no_verify+0x16b/0x16b [ 844.065674] </TASK> Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct") Signed-off-by: Tao Liu <taoliu828@163.com> Link: https://lore.kernel.org/r/20231228081457.936732-1-taoliu828@163.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
act_ct adds skb->users before defragmentation. If frags arrive in order,
the last frag's reference is reset in:

  inet_frag_reasm_prepare
    skb_morph

which is not straightforward.

However when frags arrive out of order, nobody unref the last frag, and
all frags are leaked. The situation is even worse, as initiating packet
capture can lead to a crash[0] when skb has been cloned and shared at the
same time.

Fix the issue by removing skb_get() before defragmentation. act_ct
returns TC_ACT_CONSUMED when defrag failed or in progress.

[0]:
[  843.804823] ------------[ cut here ]------------
[  843.809659] kernel BUG at net/core/skbuff.c:2091!
[  843.814516] invalid opcode: 0000 [#1] PREEMPT SMP
[  843.819296] CPU: 7 PID: 0 Comm: swapper/7 Kdump: loaded Tainted: G S 6.7.0-rc3 #2
[  843.824107] Hardware name: XFUSION 1288H V6/BC13MBSBD, BIOS 1.29 11/25/2022
[  843.828953] RIP: 0010:pskb_expand_head+0x2ac/0x300
[  843.833805] Code: 8b 70 28 48 85 f6 74 82 48 83 c6 08 bf 01 00 00 00 e8 38 bd ff ff 8b 83 c0 00 00 00 48 03 83 c8 00 00 00 e9 62 ff ff ff 0f 0b <0f> 0b e8 8d d0 ff ff e9 b3 fd ff ff 81 7c 24 14 40 01 00 00 4c 89
[  843.843698] RSP: 0018:ffffc9000cce07c0 EFLAGS: 00010202
[  843.848524] RAX: 0000000000000002 RBX: ffff88811a211d00 RCX: 0000000000000820
[  843.853299] RDX: 0000000000000640 RSI: 0000000000000000 RDI: ffff88811a211d00
[  843.857974] RBP: ffff888127d39518 R08: 00000000bee97314 R09: 0000000000000000
[  843.862584] R10: 0000000000000000 R11: ffff8881109f0000 R12: 0000000000000880
[  843.867147] R13: ffff888127d39580 R14: 0000000000000640 R15: ffff888170f7b900
[  843.871680] FS:  0000000000000000(0000) GS:ffff889ffffc0000(0000) knlGS:0000000000000000
[  843.876242] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  843.880778] CR2: 00007fa42affcfb8 CR3: 000000011433a002 CR4: 0000000000770ef0
[  843.885336] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  843.889809] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  843.894229] PKRU: 55555554
[  843.898539] Call Trace:
[  843.902772]  <IRQ>
[  843.906922]  ? __die_body+0x1e/0x60
[  843.911032]  ? die+0x3c/0x60
[  843.915037]  ? do_trap+0xe2/0x110
[  843.918911]  ? pskb_expand_head+0x2ac/0x300
[  843.922687]  ? do_error_trap+0x65/0x80
[  843.926342]  ? pskb_expand_head+0x2ac/0x300
[  843.929905]  ? exc_invalid_op+0x50/0x60
[  843.933398]  ? pskb_expand_head+0x2ac/0x300
[  843.936835]  ? asm_exc_invalid_op+0x1a/0x20
[  843.940226]  ? pskb_expand_head+0x2ac/0x300
[  843.943580]  inet_frag_reasm_prepare+0xd1/0x240
[  843.946904]  ip_defrag+0x5d4/0x870
[  843.950132]  nf_ct_handle_fragments+0xec/0x130 [nf_conntrack]
[  843.953334]  tcf_ct_act+0x252/0xd90 [act_ct]
[  843.956473]  ? tcf_mirred_act+0x516/0x5a0 [act_mirred]
[  843.959657]  tcf_action_exec+0xa1/0x160
[  843.962823]  fl_classify+0x1db/0x1f0 [cls_flower]
[  843.966010]  ? skb_clone+0x53/0xc0
[  843.969173]  tcf_classify+0x24d/0x420
[  843.972333]  tc_run+0x8f/0xf0
[  843.975465]  __netif_receive_skb_core+0x67a/0x1080
[  843.978634]  ? dev_gro_receive+0x249/0x730
[  843.981759]  __netif_receive_skb_list_core+0x12d/0x260
[  843.984869]  netif_receive_skb_list_internal+0x1cb/0x2f0
[  843.987957]  ? mlx5e_handle_rx_cqe_mpwrq_rep+0xfa/0x1a0 [mlx5_core]
[  843.991170]  napi_complete_done+0x72/0x1a0
[  843.994305]  mlx5e_napi_poll+0x28c/0x6d0 [mlx5_core]
[  843.997501]  __napi_poll+0x25/0x1b0
[  844.000627]  net_rx_action+0x256/0x330
[  844.003705]  __do_softirq+0xb3/0x29b
[  844.006718]  irq_exit_rcu+0x9e/0xc0
[  844.009672]  common_interrupt+0x86/0xa0
[  844.012537]  </IRQ>
[  844.015285]  <TASK>
[  844.017937]  asm_common_interrupt+0x26/0x40
[  844.020591] RIP: 0010:acpi_safe_halt+0x1b/0x20
[  844.023247] Code: ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 65 48 8b 04 25 00 18 03 00 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 81 d0 44 00 fb f4 <fa> c3 0f 1f 00 89 fa ec 48 8b 05 ee 88 ed 00 a9 00 00 00 80 75 11
[  844.028900] RSP: 0018:ffffc90000533e70 EFLAGS: 00000246
[  844.031725] RAX: 0000000000004000 RBX: 0000000000000001 RCX: 0000000000000000
[  844.034553] RDX: ffff889ffffc0000 RSI: ffffffff828b7f20 RDI: ffff88a090f45c64
[  844.037368] RBP: ffff88a0901a2800 R08: ffff88a090f45c00 R09: 00000000000317c0
[  844.040155] R10: 00ec812281150475 R11: ffff889fffff0e04 R12: ffffffff828b7fa0
[  844.042962] R13: ffffffff828b7f20 R14: 0000000000000001 R15: 0000000000000000
[  844.045819]  acpi_idle_enter+0x7b/0xc0
[  844.048621]  cpuidle_enter_state+0x7f/0x430
[  844.051451]  cpuidle_enter+0x2d/0x40
[  844.054279]  do_idle+0x1d4/0x240
[  844.057096]  cpu_startup_entry+0x2a/0x30
[  844.059934]  start_secondary+0x104/0x130
[  844.062787]  secondary_startup_64_no_verify+0x16b/0x16b
[  844.065674]  </TASK>

Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")
Signed-off-by: Tao Liu <taoliu828@163.com>
Link: https://lore.kernel.org/r/20231228081457.936732-1-taoliu828@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>