<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/sched, branch linux-6.5.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>net: sched: do not offload flows with a helper in act_ct</title>
<updated>2023-11-28T17:14:57+00:00</updated>
<author>
<name>Xin Long</name>
<email>lucien.xin@gmail.com</email>
</author>
<published>2023-11-13T17:53:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b4c2de028ea4d68614620fc312d73a80588e9fc1'/>
<id>b4c2de028ea4d68614620fc312d73a80588e9fc1</id>
<content type='text'>
[ Upstream commit 7cd5af0e937a197295f3aa3721031f0fbae49cff ]

There is no hardware supporting ct helper offload. However, prior to this
patch, a flower filter with a helper in the ct action can be successfully
set into the HW, for example (eth1 is a bnxt NIC):

  # tc qdisc add dev eth1 ingress_block 22 ingress
  # tc filter add block 22 proto ip flower skip_sw ip_proto tcp \
    dst_port 21 ct_state -trk action ct helper ipv4-tcp-ftp
  # tc filter show dev eth1 ingress

    filter block 22 protocol ip pref 49152 flower chain 0 handle 0x1
      eth_type ipv4
      ip_proto tcp
      dst_port 21
      ct_state -trk
      skip_sw
      in_hw in_hw_count 1   &lt;----
        action order 1: ct zone 0 helper ipv4-tcp-ftp pipe
         index 2 ref 1 bind 1
        used_hw_stats delayed

This might cause the flower filter not to work as expected in the HW.

This patch avoids this problem by simply returning -EOPNOTSUPP in
tcf_ct_offload_act_setup() to not allow to offload flows with a helper
in act_ct.

Fixes: a21b06e73191 ("net: sched: add helper support in act_ct")
Signed-off-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Reviewed-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Link: https://lore.kernel.org/r/f8685ec7702c4a448a1371a8b34b43217b583b9d.1699898008.git.lucien.xin@gmail.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 7cd5af0e937a197295f3aa3721031f0fbae49cff ]

There is no hardware supporting ct helper offload. However, prior to this
patch, a flower filter with a helper in the ct action can be successfully
set into the HW, for example (eth1 is a bnxt NIC):

  # tc qdisc add dev eth1 ingress_block 22 ingress
  # tc filter add block 22 proto ip flower skip_sw ip_proto tcp \
    dst_port 21 ct_state -trk action ct helper ipv4-tcp-ftp
  # tc filter show dev eth1 ingress

    filter block 22 protocol ip pref 49152 flower chain 0 handle 0x1
      eth_type ipv4
      ip_proto tcp
      dst_port 21
      ct_state -trk
      skip_sw
      in_hw in_hw_count 1   &lt;----
        action order 1: ct zone 0 helper ipv4-tcp-ftp pipe
         index 2 ref 1 bind 1
        used_hw_stats delayed

This might cause the flower filter not to work as expected in the HW.

This patch avoids this problem by simply returning -EOPNOTSUPP in
tcf_ct_offload_act_setup() to not allow to offload flows with a helper
in act_ct.

Fixes: a21b06e73191 ("net: sched: add helper support in act_ct")
Signed-off-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Reviewed-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Link: https://lore.kernel.org/r/f8685ec7702c4a448a1371a8b34b43217b583b9d.1699898008.git.lucien.xin@gmail.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net/sched: act_ct: Always fill offloading tuple iifidx</title>
<updated>2023-11-20T10:57:24+00:00</updated>
<author>
<name>Vlad Buslov</name>
<email>vladbu@nvidia.com</email>
</author>
<published>2023-11-03T15:14:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c59f928177192387a5e5586f022ffdad52fc802c'/>
<id>c59f928177192387a5e5586f022ffdad52fc802c</id>
<content type='text'>
[ Upstream commit 9bc64bd0cd765f696fcd40fc98909b1f7c73b2ba ]

Referenced commit doesn't always set iifidx when offloading the flow to
hardware. Fix the following cases:

- nf_conn_act_ct_ext_fill() is called before extension is created with
nf_conn_act_ct_ext_add() in tcf_ct_act(). This can cause rule offload with
unspecified iifidx when connection is offloaded after only single
original-direction packet has been processed by tc data path. Always fill
the new nf_conn_act_ct_ext instance after creating it in
nf_conn_act_ct_ext_add().

- Offloading of unidirectional UDP NEW connections is now supported, but ct
flow iifidx field is not updated when connection is promoted to
bidirectional which can result reply-direction iifidx to be zero when
refreshing the connection. Fill in the extension and update flow iifidx
before calling flow_offload_refresh().

Fixes: 9795ded7f924 ("net/sched: act_ct: Fill offloading tuple iifidx")
Reviewed-by: Paul Blakey &lt;paulb@nvidia.com&gt;
Signed-off-by: Vlad Buslov &lt;vladbu@nvidia.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.org&gt;
Fixes: 6a9bad0069cf ("net/sched: act_ct: offload UDP NEW connections")
Link: https://lore.kernel.org/r/20231103151410.764271-1-vladbu@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 9bc64bd0cd765f696fcd40fc98909b1f7c73b2ba ]

Referenced commit doesn't always set iifidx when offloading the flow to
hardware. Fix the following cases:

- nf_conn_act_ct_ext_fill() is called before extension is created with
nf_conn_act_ct_ext_add() in tcf_ct_act(). This can cause rule offload with
unspecified iifidx when connection is offloaded after only single
original-direction packet has been processed by tc data path. Always fill
the new nf_conn_act_ct_ext instance after creating it in
nf_conn_act_ct_ext_add().

- Offloading of unidirectional UDP NEW connections is now supported, but ct
flow iifidx field is not updated when connection is promoted to
bidirectional which can result reply-direction iifidx to be zero when
refreshing the connection. Fill in the extension and update flow iifidx
before calling flow_offload_refresh().

Fixes: 9795ded7f924 ("net/sched: act_ct: Fill offloading tuple iifidx")
Reviewed-by: Paul Blakey &lt;paulb@nvidia.com&gt;
Signed-off-by: Vlad Buslov &lt;vladbu@nvidia.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.org&gt;
Fixes: 6a9bad0069cf ("net/sched: act_ct: offload UDP NEW connections")
Link: https://lore.kernel.org/r/20231103151410.764271-1-vladbu@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: sched: cls_u32: Fix allocation size in u32_init()</title>
<updated>2023-11-08T13:08:56+00:00</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavoars@kernel.org</email>
</author>
<published>2023-10-04T13:19:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=92705546718b56a33b89664be7c2fd9683439225'/>
<id>92705546718b56a33b89664be7c2fd9683439225</id>
<content type='text'>
[ 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-&gt;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-&gt;ht, 1)` translates to:

sizeof(*tp_c) + sizeof(tp_c-&gt;hlist-&gt;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-&gt;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 &lt;u32_init+0xfc&gt;
|                        2cf8: R_X86_64_PC32     kmalloc_caches+0xc
|-    2cfc:      mov    $0x98,%edx
|+    2cfc:      mov    $0x90,%edx

Reported-by: Alejandro Colomar &lt;alx@kernel.org&gt;
Closes: https://lore.kernel.org/lkml/09b4a2ce-da74-3a19-6961-67883f634d98@kernel.org/
Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Acked-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ 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-&gt;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-&gt;ht, 1)` translates to:

sizeof(*tp_c) + sizeof(tp_c-&gt;hlist-&gt;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-&gt;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 &lt;u32_init+0xfc&gt;
|                        2cf8: R_X86_64_PC32     kmalloc_caches+0xc
|-    2cfc:      mov    $0x98,%edx
|+    2cfc:      mov    $0x90,%edx

Reported-by: Alejandro Colomar &lt;alx@kernel.org&gt;
Closes: https://lore.kernel.org/lkml/09b4a2ce-da74-3a19-6961-67883f634d98@kernel.org/
Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
Acked-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net/sched: act_ct: additional checks for outdated flows</title>
<updated>2023-11-02T08:36:55+00:00</updated>
<author>
<name>Vlad Buslov</name>
<email>vladbu@nvidia.com</email>
</author>
<published>2023-10-24T19:58:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=180069f6b8e83421fc5604e05273b95067aee344'/>
<id>180069f6b8e83421fc5604e05273b95067aee344</id>
<content type='text'>
[ Upstream commit a63b6622120cd03a304796dbccb80655b3a21798 ]

Current nf_flow_is_outdated() implementation considers any flow table flow
which state diverged from its underlying CT connection status for teardown
which can be problematic in the following cases:

- Flow has never been offloaded to hardware in the first place either
because flow table has hardware offload disabled (flag
NF_FLOWTABLE_HW_OFFLOAD is not set) or because it is still pending on 'add'
workqueue to be offloaded for the first time. The former is incorrect, the
later generates excessive deletions and additions of flows.

- Flow is already pending to be updated on the workqueue. Tearing down such
flows will also generate excessive removals from the flow table, especially
on highly loaded system where the latency to re-offload a flow via 'add'
workqueue can be quite high.

When considering a flow for teardown as outdated verify that it is both
offloaded to hardware and doesn't have any pending updates.

Fixes: 41f2c7c342d3 ("net/sched: act_ct: Fix promotion of offloaded unreplied tuple")
Reviewed-by: Paul Blakey &lt;paulb@nvidia.com&gt;
Signed-off-by: Vlad Buslov &lt;vladbu@nvidia.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit a63b6622120cd03a304796dbccb80655b3a21798 ]

Current nf_flow_is_outdated() implementation considers any flow table flow
which state diverged from its underlying CT connection status for teardown
which can be problematic in the following cases:

- Flow has never been offloaded to hardware in the first place either
because flow table has hardware offload disabled (flag
NF_FLOWTABLE_HW_OFFLOAD is not set) or because it is still pending on 'add'
workqueue to be offloaded for the first time. The former is incorrect, the
later generates excessive deletions and additions of flows.

- Flow is already pending to be updated on the workqueue. Tearing down such
flows will also generate excessive removals from the flow table, especially
on highly loaded system where the latency to re-offload a flow via 'add'
workqueue can be quite high.

When considering a flow for teardown as outdated verify that it is both
offloaded to hardware and doesn't have any pending updates.

Fixes: 41f2c7c342d3 ("net/sched: act_ct: Fix promotion of offloaded unreplied tuple")
Reviewed-by: Paul Blakey &lt;paulb@nvidia.com&gt;
Signed-off-by: Vlad Buslov &lt;vladbu@nvidia.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: flowtable: GC pushes back packets to classic path</title>
<updated>2023-11-02T08:36:55+00:00</updated>
<author>
<name>Pablo Neira Ayuso</name>
<email>pablo@netfilter.org</email>
</author>
<published>2023-10-24T19:09:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=533c24b368d7c97c31175eb0191f05d148685e5f'/>
<id>533c24b368d7c97c31175eb0191f05d148685e5f</id>
<content type='text'>
[ Upstream commit 735795f68b37e9bb49f642407a0d49b1631ea1c7 ]

Since 41f2c7c342d3 ("net/sched: act_ct: Fix promotion of offloaded
unreplied tuple"), flowtable GC pushes back flows with IPS_SEEN_REPLY
back to classic path in every run, ie. every second. This is because of
a new check for NF_FLOW_HW_ESTABLISHED which is specific of sched/act_ct.

In Netfilter's flowtable case, NF_FLOW_HW_ESTABLISHED never gets set on
and IPS_SEEN_REPLY is unreliable since users decide when to offload the
flow before, such bit might be set on at a later stage.

Fix it by adding a custom .gc handler that sched/act_ct can use to
deal with its NF_FLOW_HW_ESTABLISHED bit.

Fixes: 41f2c7c342d3 ("net/sched: act_ct: Fix promotion of offloaded unreplied tuple")
Reported-by: Vladimir Smelhaus &lt;vl.sm@email.cz&gt;
Reviewed-by: Paul Blakey &lt;paulb@nvidia.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 735795f68b37e9bb49f642407a0d49b1631ea1c7 ]

Since 41f2c7c342d3 ("net/sched: act_ct: Fix promotion of offloaded
unreplied tuple"), flowtable GC pushes back flows with IPS_SEEN_REPLY
back to classic path in every run, ie. every second. This is because of
a new check for NF_FLOW_HW_ESTABLISHED which is specific of sched/act_ct.

In Netfilter's flowtable case, NF_FLOW_HW_ESTABLISHED never gets set on
and IPS_SEEN_REPLY is unreliable since users decide when to offload the
flow before, such bit might be set on at a later stage.

Fix it by adding a custom .gc handler that sched/act_ct can use to
deal with its NF_FLOW_HW_ESTABLISHED bit.

Fixes: 41f2c7c342d3 ("net/sched: act_ct: Fix promotion of offloaded unreplied tuple")
Reported-by: Vladimir Smelhaus &lt;vl.sm@email.cz&gt;
Reviewed-by: Paul Blakey &lt;paulb@nvidia.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net/sched: sch_hfsc: upgrade 'rt' to 'sc' when it becomes a inner curve</title>
<updated>2023-10-25T10:16:15+00:00</updated>
<author>
<name>Pedro Tammela</name>
<email>pctammela@mojatatu.com</email>
</author>
<published>2023-10-17T14:36:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a851f8c9353329122031d93351c32150acf046ca'/>
<id>a851f8c9353329122031d93351c32150acf046ca</id>
<content type='text'>
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-&gt;v2: https://lore.kernel.org/all/20231013151057.2611860-1-pctammela@mojatatu.com/
- Correct 'Fixes' tag and merge with revert (Jakub)

Cc: Christian Theune &lt;ct@flyingcircus.io&gt;
Cc: Budimir Markovic &lt;markovicbudimir@gmail.com&gt;
Fixes: b3d26c5702c7 ("net/sched: sch_hfsc: Ensure inner classes have fsc curve")
Signed-off-by: Pedro Tammela &lt;pctammela@mojatatu.com&gt;
Acked-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Link: https://lore.kernel.org/r/20231017143602.3191556-1-pctammela@mojatatu.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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-&gt;v2: https://lore.kernel.org/all/20231013151057.2611860-1-pctammela@mojatatu.com/
- Correct 'Fixes' tag and merge with revert (Jakub)

Cc: Christian Theune &lt;ct@flyingcircus.io&gt;
Cc: Budimir Markovic &lt;markovicbudimir@gmail.com&gt;
Fixes: b3d26c5702c7 ("net/sched: sch_hfsc: Ensure inner classes have fsc curve")
Signed-off-by: Pedro Tammela &lt;pctammela@mojatatu.com&gt;
Acked-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Link: https://lore.kernel.org/r/20231017143602.3191556-1-pctammela@mojatatu.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: sched: sch_qfq: Fix UAF in qfq_dequeue()</title>
<updated>2023-09-19T10:30:18+00:00</updated>
<author>
<name>valis</name>
<email>sec@valis.email</email>
</author>
<published>2023-09-01T16:22:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e5471b82c36396e809817cb988dfc4bce0a688cb'/>
<id>e5471b82c36396e809817cb988dfc4bce0a688cb</id>
<content type='text'>
[ Upstream commit 8fc134fee27f2263988ae38920bc03da416b03d8 ]

When the plug qdisc is used as a class of the qfq qdisc it could trigger a
UAF. This issue can be reproduced with following commands:

  tc qdisc add dev lo root handle 1: qfq
  tc class add dev lo parent 1: classid 1:1 qfq weight 1 maxpkt 512
  tc qdisc add dev lo parent 1:1 handle 2: plug
  tc filter add dev lo parent 1: basic classid 1:1
  ping -c1 127.0.0.1

and boom:

[  285.353793] BUG: KASAN: slab-use-after-free in qfq_dequeue+0xa7/0x7f0
[  285.354910] Read of size 4 at addr ffff8880bad312a8 by task ping/144
[  285.355903]
[  285.356165] CPU: 1 PID: 144 Comm: ping Not tainted 6.5.0-rc3+ #4
[  285.357112] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
[  285.358376] Call Trace:
[  285.358773]  &lt;IRQ&gt;
[  285.359109]  dump_stack_lvl+0x44/0x60
[  285.359708]  print_address_description.constprop.0+0x2c/0x3c0
[  285.360611]  kasan_report+0x10c/0x120
[  285.361195]  ? qfq_dequeue+0xa7/0x7f0
[  285.361780]  qfq_dequeue+0xa7/0x7f0
[  285.362342]  __qdisc_run+0xf1/0x970
[  285.362903]  net_tx_action+0x28e/0x460
[  285.363502]  __do_softirq+0x11b/0x3de
[  285.364097]  do_softirq.part.0+0x72/0x90
[  285.364721]  &lt;/IRQ&gt;
[  285.365072]  &lt;TASK&gt;
[  285.365422]  __local_bh_enable_ip+0x77/0x90
[  285.366079]  __dev_queue_xmit+0x95f/0x1550
[  285.366732]  ? __pfx_csum_and_copy_from_iter+0x10/0x10
[  285.367526]  ? __pfx___dev_queue_xmit+0x10/0x10
[  285.368259]  ? __build_skb_around+0x129/0x190
[  285.368960]  ? ip_generic_getfrag+0x12c/0x170
[  285.369653]  ? __pfx_ip_generic_getfrag+0x10/0x10
[  285.370390]  ? csum_partial+0x8/0x20
[  285.370961]  ? raw_getfrag+0xe5/0x140
[  285.371559]  ip_finish_output2+0x539/0xa40
[  285.372222]  ? __pfx_ip_finish_output2+0x10/0x10
[  285.372954]  ip_output+0x113/0x1e0
[  285.373512]  ? __pfx_ip_output+0x10/0x10
[  285.374130]  ? icmp_out_count+0x49/0x60
[  285.374739]  ? __pfx_ip_finish_output+0x10/0x10
[  285.375457]  ip_push_pending_frames+0xf3/0x100
[  285.376173]  raw_sendmsg+0xef5/0x12d0
[  285.376760]  ? do_syscall_64+0x40/0x90
[  285.377359]  ? __static_call_text_end+0x136578/0x136578
[  285.378173]  ? do_syscall_64+0x40/0x90
[  285.378772]  ? kasan_enable_current+0x11/0x20
[  285.379469]  ? __pfx_raw_sendmsg+0x10/0x10
[  285.380137]  ? __sock_create+0x13e/0x270
[  285.380673]  ? __sys_socket+0xf3/0x180
[  285.381174]  ? __x64_sys_socket+0x3d/0x50
[  285.381725]  ? entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.382425]  ? __rcu_read_unlock+0x48/0x70
[  285.382975]  ? ip4_datagram_release_cb+0xd8/0x380
[  285.383608]  ? __pfx_ip4_datagram_release_cb+0x10/0x10
[  285.384295]  ? preempt_count_sub+0x14/0xc0
[  285.384844]  ? __list_del_entry_valid+0x76/0x140
[  285.385467]  ? _raw_spin_lock_bh+0x87/0xe0
[  285.386014]  ? __pfx__raw_spin_lock_bh+0x10/0x10
[  285.386645]  ? release_sock+0xa0/0xd0
[  285.387148]  ? preempt_count_sub+0x14/0xc0
[  285.387712]  ? freeze_secondary_cpus+0x348/0x3c0
[  285.388341]  ? aa_sk_perm+0x177/0x390
[  285.388856]  ? __pfx_aa_sk_perm+0x10/0x10
[  285.389441]  ? check_stack_object+0x22/0x70
[  285.390032]  ? inet_send_prepare+0x2f/0x120
[  285.390603]  ? __pfx_inet_sendmsg+0x10/0x10
[  285.391172]  sock_sendmsg+0xcc/0xe0
[  285.391667]  __sys_sendto+0x190/0x230
[  285.392168]  ? __pfx___sys_sendto+0x10/0x10
[  285.392727]  ? kvm_clock_get_cycles+0x14/0x30
[  285.393328]  ? set_normalized_timespec64+0x57/0x70
[  285.393980]  ? _raw_spin_unlock_irq+0x1b/0x40
[  285.394578]  ? __x64_sys_clock_gettime+0x11c/0x160
[  285.395225]  ? __pfx___x64_sys_clock_gettime+0x10/0x10
[  285.395908]  ? _copy_to_user+0x3e/0x60
[  285.396432]  ? exit_to_user_mode_prepare+0x1a/0x120
[  285.397086]  ? syscall_exit_to_user_mode+0x22/0x50
[  285.397734]  ? do_syscall_64+0x71/0x90
[  285.398258]  __x64_sys_sendto+0x74/0x90
[  285.398786]  do_syscall_64+0x64/0x90
[  285.399273]  ? exit_to_user_mode_prepare+0x1a/0x120
[  285.399949]  ? syscall_exit_to_user_mode+0x22/0x50
[  285.400605]  ? do_syscall_64+0x71/0x90
[  285.401124]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.401807] RIP: 0033:0x495726
[  285.402233] Code: ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 11 b8 2c 00 00 00 0f 09
[  285.404683] RSP: 002b:00007ffcc25fb618 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[  285.405677] RAX: ffffffffffffffda RBX: 0000000000000040 RCX: 0000000000495726
[  285.406628] RDX: 0000000000000040 RSI: 0000000002518750 RDI: 0000000000000000
[  285.407565] RBP: 00000000005205ef R08: 00000000005f8838 R09: 000000000000001c
[  285.408523] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000002517634
[  285.409460] R13: 00007ffcc25fb6f0 R14: 0000000000000003 R15: 0000000000000000
[  285.410403]  &lt;/TASK&gt;
[  285.410704]
[  285.410929] Allocated by task 144:
[  285.411402]  kasan_save_stack+0x1e/0x40
[  285.411926]  kasan_set_track+0x21/0x30
[  285.412442]  __kasan_slab_alloc+0x55/0x70
[  285.412973]  kmem_cache_alloc_node+0x187/0x3d0
[  285.413567]  __alloc_skb+0x1b4/0x230
[  285.414060]  __ip_append_data+0x17f7/0x1b60
[  285.414633]  ip_append_data+0x97/0xf0
[  285.415144]  raw_sendmsg+0x5a8/0x12d0
[  285.415640]  sock_sendmsg+0xcc/0xe0
[  285.416117]  __sys_sendto+0x190/0x230
[  285.416626]  __x64_sys_sendto+0x74/0x90
[  285.417145]  do_syscall_64+0x64/0x90
[  285.417624]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.418306]
[  285.418531] Freed by task 144:
[  285.418960]  kasan_save_stack+0x1e/0x40
[  285.419469]  kasan_set_track+0x21/0x30
[  285.419988]  kasan_save_free_info+0x27/0x40
[  285.420556]  ____kasan_slab_free+0x109/0x1a0
[  285.421146]  kmem_cache_free+0x1c2/0x450
[  285.421680]  __netif_receive_skb_core+0x2ce/0x1870
[  285.422333]  __netif_receive_skb_one_core+0x97/0x140
[  285.423003]  process_backlog+0x100/0x2f0
[  285.423537]  __napi_poll+0x5c/0x2d0
[  285.424023]  net_rx_action+0x2be/0x560
[  285.424510]  __do_softirq+0x11b/0x3de
[  285.425034]
[  285.425254] The buggy address belongs to the object at ffff8880bad31280
[  285.425254]  which belongs to the cache skbuff_head_cache of size 224
[  285.426993] The buggy address is located 40 bytes inside of
[  285.426993]  freed 224-byte region [ffff8880bad31280, ffff8880bad31360)
[  285.428572]
[  285.428798] The buggy address belongs to the physical page:
[  285.429540] page:00000000f4b77674 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xbad31
[  285.430758] flags: 0x100000000000200(slab|node=0|zone=1)
[  285.431447] page_type: 0xffffffff()
[  285.431934] raw: 0100000000000200 ffff88810094a8c0 dead000000000122 0000000000000000
[  285.432757] raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
[  285.433562] page dumped because: kasan: bad access detected
[  285.434144]
[  285.434320] Memory state around the buggy address:
[  285.434828]  ffff8880bad31180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.435580]  ffff8880bad31200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.436264] &gt;ffff8880bad31280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  285.436777]                                   ^
[  285.437106]  ffff8880bad31300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
[  285.437616]  ffff8880bad31380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.438126] ==================================================================
[  285.438662] Disabling lock debugging due to kernel taint

Fix this by:
1. Changing sch_plug's .peek handler to qdisc_peek_dequeued(), a
function compatible with non-work-conserving qdiscs
2. Checking the return value of qdisc_dequeue_peeked() in sch_qfq.

Fixes: 462dbc9101ac ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
Reported-by: valis &lt;sec@valis.email&gt;
Signed-off-by: valis &lt;sec@valis.email&gt;
Signed-off-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Link: https://lore.kernel.org/r/20230901162237.11525-1-jhs@mojatatu.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 8fc134fee27f2263988ae38920bc03da416b03d8 ]

When the plug qdisc is used as a class of the qfq qdisc it could trigger a
UAF. This issue can be reproduced with following commands:

  tc qdisc add dev lo root handle 1: qfq
  tc class add dev lo parent 1: classid 1:1 qfq weight 1 maxpkt 512
  tc qdisc add dev lo parent 1:1 handle 2: plug
  tc filter add dev lo parent 1: basic classid 1:1
  ping -c1 127.0.0.1

and boom:

[  285.353793] BUG: KASAN: slab-use-after-free in qfq_dequeue+0xa7/0x7f0
[  285.354910] Read of size 4 at addr ffff8880bad312a8 by task ping/144
[  285.355903]
[  285.356165] CPU: 1 PID: 144 Comm: ping Not tainted 6.5.0-rc3+ #4
[  285.357112] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
[  285.358376] Call Trace:
[  285.358773]  &lt;IRQ&gt;
[  285.359109]  dump_stack_lvl+0x44/0x60
[  285.359708]  print_address_description.constprop.0+0x2c/0x3c0
[  285.360611]  kasan_report+0x10c/0x120
[  285.361195]  ? qfq_dequeue+0xa7/0x7f0
[  285.361780]  qfq_dequeue+0xa7/0x7f0
[  285.362342]  __qdisc_run+0xf1/0x970
[  285.362903]  net_tx_action+0x28e/0x460
[  285.363502]  __do_softirq+0x11b/0x3de
[  285.364097]  do_softirq.part.0+0x72/0x90
[  285.364721]  &lt;/IRQ&gt;
[  285.365072]  &lt;TASK&gt;
[  285.365422]  __local_bh_enable_ip+0x77/0x90
[  285.366079]  __dev_queue_xmit+0x95f/0x1550
[  285.366732]  ? __pfx_csum_and_copy_from_iter+0x10/0x10
[  285.367526]  ? __pfx___dev_queue_xmit+0x10/0x10
[  285.368259]  ? __build_skb_around+0x129/0x190
[  285.368960]  ? ip_generic_getfrag+0x12c/0x170
[  285.369653]  ? __pfx_ip_generic_getfrag+0x10/0x10
[  285.370390]  ? csum_partial+0x8/0x20
[  285.370961]  ? raw_getfrag+0xe5/0x140
[  285.371559]  ip_finish_output2+0x539/0xa40
[  285.372222]  ? __pfx_ip_finish_output2+0x10/0x10
[  285.372954]  ip_output+0x113/0x1e0
[  285.373512]  ? __pfx_ip_output+0x10/0x10
[  285.374130]  ? icmp_out_count+0x49/0x60
[  285.374739]  ? __pfx_ip_finish_output+0x10/0x10
[  285.375457]  ip_push_pending_frames+0xf3/0x100
[  285.376173]  raw_sendmsg+0xef5/0x12d0
[  285.376760]  ? do_syscall_64+0x40/0x90
[  285.377359]  ? __static_call_text_end+0x136578/0x136578
[  285.378173]  ? do_syscall_64+0x40/0x90
[  285.378772]  ? kasan_enable_current+0x11/0x20
[  285.379469]  ? __pfx_raw_sendmsg+0x10/0x10
[  285.380137]  ? __sock_create+0x13e/0x270
[  285.380673]  ? __sys_socket+0xf3/0x180
[  285.381174]  ? __x64_sys_socket+0x3d/0x50
[  285.381725]  ? entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.382425]  ? __rcu_read_unlock+0x48/0x70
[  285.382975]  ? ip4_datagram_release_cb+0xd8/0x380
[  285.383608]  ? __pfx_ip4_datagram_release_cb+0x10/0x10
[  285.384295]  ? preempt_count_sub+0x14/0xc0
[  285.384844]  ? __list_del_entry_valid+0x76/0x140
[  285.385467]  ? _raw_spin_lock_bh+0x87/0xe0
[  285.386014]  ? __pfx__raw_spin_lock_bh+0x10/0x10
[  285.386645]  ? release_sock+0xa0/0xd0
[  285.387148]  ? preempt_count_sub+0x14/0xc0
[  285.387712]  ? freeze_secondary_cpus+0x348/0x3c0
[  285.388341]  ? aa_sk_perm+0x177/0x390
[  285.388856]  ? __pfx_aa_sk_perm+0x10/0x10
[  285.389441]  ? check_stack_object+0x22/0x70
[  285.390032]  ? inet_send_prepare+0x2f/0x120
[  285.390603]  ? __pfx_inet_sendmsg+0x10/0x10
[  285.391172]  sock_sendmsg+0xcc/0xe0
[  285.391667]  __sys_sendto+0x190/0x230
[  285.392168]  ? __pfx___sys_sendto+0x10/0x10
[  285.392727]  ? kvm_clock_get_cycles+0x14/0x30
[  285.393328]  ? set_normalized_timespec64+0x57/0x70
[  285.393980]  ? _raw_spin_unlock_irq+0x1b/0x40
[  285.394578]  ? __x64_sys_clock_gettime+0x11c/0x160
[  285.395225]  ? __pfx___x64_sys_clock_gettime+0x10/0x10
[  285.395908]  ? _copy_to_user+0x3e/0x60
[  285.396432]  ? exit_to_user_mode_prepare+0x1a/0x120
[  285.397086]  ? syscall_exit_to_user_mode+0x22/0x50
[  285.397734]  ? do_syscall_64+0x71/0x90
[  285.398258]  __x64_sys_sendto+0x74/0x90
[  285.398786]  do_syscall_64+0x64/0x90
[  285.399273]  ? exit_to_user_mode_prepare+0x1a/0x120
[  285.399949]  ? syscall_exit_to_user_mode+0x22/0x50
[  285.400605]  ? do_syscall_64+0x71/0x90
[  285.401124]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.401807] RIP: 0033:0x495726
[  285.402233] Code: ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 11 b8 2c 00 00 00 0f 09
[  285.404683] RSP: 002b:00007ffcc25fb618 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[  285.405677] RAX: ffffffffffffffda RBX: 0000000000000040 RCX: 0000000000495726
[  285.406628] RDX: 0000000000000040 RSI: 0000000002518750 RDI: 0000000000000000
[  285.407565] RBP: 00000000005205ef R08: 00000000005f8838 R09: 000000000000001c
[  285.408523] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000002517634
[  285.409460] R13: 00007ffcc25fb6f0 R14: 0000000000000003 R15: 0000000000000000
[  285.410403]  &lt;/TASK&gt;
[  285.410704]
[  285.410929] Allocated by task 144:
[  285.411402]  kasan_save_stack+0x1e/0x40
[  285.411926]  kasan_set_track+0x21/0x30
[  285.412442]  __kasan_slab_alloc+0x55/0x70
[  285.412973]  kmem_cache_alloc_node+0x187/0x3d0
[  285.413567]  __alloc_skb+0x1b4/0x230
[  285.414060]  __ip_append_data+0x17f7/0x1b60
[  285.414633]  ip_append_data+0x97/0xf0
[  285.415144]  raw_sendmsg+0x5a8/0x12d0
[  285.415640]  sock_sendmsg+0xcc/0xe0
[  285.416117]  __sys_sendto+0x190/0x230
[  285.416626]  __x64_sys_sendto+0x74/0x90
[  285.417145]  do_syscall_64+0x64/0x90
[  285.417624]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[  285.418306]
[  285.418531] Freed by task 144:
[  285.418960]  kasan_save_stack+0x1e/0x40
[  285.419469]  kasan_set_track+0x21/0x30
[  285.419988]  kasan_save_free_info+0x27/0x40
[  285.420556]  ____kasan_slab_free+0x109/0x1a0
[  285.421146]  kmem_cache_free+0x1c2/0x450
[  285.421680]  __netif_receive_skb_core+0x2ce/0x1870
[  285.422333]  __netif_receive_skb_one_core+0x97/0x140
[  285.423003]  process_backlog+0x100/0x2f0
[  285.423537]  __napi_poll+0x5c/0x2d0
[  285.424023]  net_rx_action+0x2be/0x560
[  285.424510]  __do_softirq+0x11b/0x3de
[  285.425034]
[  285.425254] The buggy address belongs to the object at ffff8880bad31280
[  285.425254]  which belongs to the cache skbuff_head_cache of size 224
[  285.426993] The buggy address is located 40 bytes inside of
[  285.426993]  freed 224-byte region [ffff8880bad31280, ffff8880bad31360)
[  285.428572]
[  285.428798] The buggy address belongs to the physical page:
[  285.429540] page:00000000f4b77674 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xbad31
[  285.430758] flags: 0x100000000000200(slab|node=0|zone=1)
[  285.431447] page_type: 0xffffffff()
[  285.431934] raw: 0100000000000200 ffff88810094a8c0 dead000000000122 0000000000000000
[  285.432757] raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
[  285.433562] page dumped because: kasan: bad access detected
[  285.434144]
[  285.434320] Memory state around the buggy address:
[  285.434828]  ffff8880bad31180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.435580]  ffff8880bad31200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.436264] &gt;ffff8880bad31280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  285.436777]                                   ^
[  285.437106]  ffff8880bad31300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
[  285.437616]  ffff8880bad31380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  285.438126] ==================================================================
[  285.438662] Disabling lock debugging due to kernel taint

Fix this by:
1. Changing sch_plug's .peek handler to qdisc_peek_dequeued(), a
function compatible with non-work-conserving qdiscs
2. Checking the return value of qdisc_dequeue_peeked() in sch_qfq.

Fixes: 462dbc9101ac ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
Reported-by: valis &lt;sec@valis.email&gt;
Signed-off-by: valis &lt;sec@valis.email&gt;
Signed-off-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Link: https://lore.kernel.org/r/20230901162237.11525-1-jhs@mojatatu.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net/sched: fq_pie: avoid stalls in fq_pie_timer()</title>
<updated>2023-09-19T10:30:16+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2023-08-29T12:35:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e093000e7d13569c9cb07d7500acd5142c3c43cb'/>
<id>e093000e7d13569c9cb07d7500acd5142c3c43cb</id>
<content type='text'>
[ Upstream commit 8c21ab1bae945686c602c5bfa4e3f3352c2452c5 ]

When setting a high number of flows (limit being 65536),
fq_pie_timer() is currently using too much time as syzbot reported.

Add logic to yield the cpu every 2048 flows (less than 150 usec
on debug kernels).
It should also help by not blocking qdisc fast paths for too long.
Worst case (65536 flows) would need 31 jiffies for a complete scan.

Relevant extract from syzbot report:

rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2663 jiffies s: 873 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5177 Comm: syz-executor273 Not tainted 6.5.0-syzkaller-00453-g727dbda16b83 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:write_comp_data+0x21/0x90 kernel/kcov.c:236
Code: 2e 0f 1f 84 00 00 00 00 00 65 8b 05 01 b2 7d 7e 49 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 80 b9 03 00 &lt;a9&gt; 00 01 ff 00 74 0e 85 f6 74 59 8b 82 04 16 00 00 85 c0 74 4f 8b
RSP: 0018:ffffc90000007bb8 EFLAGS: 00000206
RAX: 0000000000000101 RBX: ffffc9000dc0d140 RCX: ffffffff885893b0
RDX: ffff88807c075940 RSI: 0000000000000100 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc9000dc0d178
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000555555d54380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6b442f6130 CR3: 000000006fe1c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 &lt;NMI&gt;
 &lt;/NMI&gt;
 &lt;IRQ&gt;
 pie_calculate_probability+0x480/0x850 net/sched/sch_pie.c:415
 fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387
 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700

Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler")
Link: https://lore.kernel.org/lkml/00000000000017ad3f06040bf394@google.com/
Reported-by: syzbot+e46fbd5289363464bc13@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Michal Kubiak &lt;michal.kubiak@intel.com&gt;
Reviewed-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Link: https://lore.kernel.org/r/20230829123541.3745013-1-edumazet@google.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 8c21ab1bae945686c602c5bfa4e3f3352c2452c5 ]

When setting a high number of flows (limit being 65536),
fq_pie_timer() is currently using too much time as syzbot reported.

Add logic to yield the cpu every 2048 flows (less than 150 usec
on debug kernels).
It should also help by not blocking qdisc fast paths for too long.
Worst case (65536 flows) would need 31 jiffies for a complete scan.

Relevant extract from syzbot report:

rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2663 jiffies s: 873 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5177 Comm: syz-executor273 Not tainted 6.5.0-syzkaller-00453-g727dbda16b83 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:write_comp_data+0x21/0x90 kernel/kcov.c:236
Code: 2e 0f 1f 84 00 00 00 00 00 65 8b 05 01 b2 7d 7e 49 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 80 b9 03 00 &lt;a9&gt; 00 01 ff 00 74 0e 85 f6 74 59 8b 82 04 16 00 00 85 c0 74 4f 8b
RSP: 0018:ffffc90000007bb8 EFLAGS: 00000206
RAX: 0000000000000101 RBX: ffffc9000dc0d140 RCX: ffffffff885893b0
RDX: ffff88807c075940 RSI: 0000000000000100 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc9000dc0d178
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000555555d54380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6b442f6130 CR3: 000000006fe1c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 &lt;NMI&gt;
 &lt;/NMI&gt;
 &lt;IRQ&gt;
 pie_calculate_probability+0x480/0x850 net/sched/sch_pie.c:415
 fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387
 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700

Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler")
Link: https://lore.kernel.org/lkml/00000000000017ad3f06040bf394@google.com/
Reported-by: syzbot+e46fbd5289363464bc13@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Michal Kubiak &lt;michal.kubiak@intel.com&gt;
Reviewed-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Link: https://lore.kernel.org/r/20230829123541.3745013-1-edumazet@google.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net/sched: sch_hfsc: Ensure inner classes have fsc curve</title>
<updated>2023-09-13T07:53:11+00:00</updated>
<author>
<name>Budimir Markovic</name>
<email>markovicbudimir@gmail.com</email>
</author>
<published>2023-08-24T08:49:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=eb07894c51c7d6bb8d00948a3e6e7b52c791e93e'/>
<id>eb07894c51c7d6bb8d00948a3e6e7b52c791e93e</id>
<content type='text'>
[ Upstream commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f ]

HFSC assumes that inner classes have an fsc curve, but it is currently
possible for classes without an fsc curve to become parents. This leads
to bugs including a use-after-free.

Don't allow non-root classes without HFSC_FSC to become parents.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Budimir Markovic &lt;markovicbudimir@gmail.com&gt;
Signed-off-by: Budimir Markovic &lt;markovicbudimir@gmail.com&gt;
Acked-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Link: https://lore.kernel.org/r/20230824084905.422-1-markovicbudimir@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f ]

HFSC assumes that inner classes have an fsc curve, but it is currently
possible for classes without an fsc curve to become parents. This leads
to bugs including a use-after-free.

Don't allow non-root classes without HFSC_FSC to become parents.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Budimir Markovic &lt;markovicbudimir@gmail.com&gt;
Signed-off-by: Budimir Markovic &lt;markovicbudimir@gmail.com&gt;
Acked-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Link: https://lore.kernel.org/r/20230824084905.422-1-markovicbudimir@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: annotate data-races around sk-&gt;sk_lingertime</title>
<updated>2023-09-13T07:53:08+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2023-08-19T04:06:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=73ccc8473082a54826c9fd5262d7b98cd4cb360c'/>
<id>73ccc8473082a54826c9fd5262d7b98cd4cb360c</id>
<content type='text'>
[ Upstream commit bc1fb82ae11753c5dec53c667a055dc37796dbd2 ]

sk_getsockopt() runs locklessly. This means sk-&gt;sk_lingertime
can be read while other threads are changing its value.

Other reads also happen without socket lock being held,
and must be annotated.

Remove preprocessor logic using BITS_PER_LONG, compilers
are smart enough to figure this by themselves.

v2: fixed a clang W=1 (-Wtautological-constant-out-of-range-compare) warning
    (Jakub)

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit bc1fb82ae11753c5dec53c667a055dc37796dbd2 ]

sk_getsockopt() runs locklessly. This means sk-&gt;sk_lingertime
can be read while other threads are changing its value.

Other reads also happen without socket lock being held,
and must be annotated.

Remove preprocessor logic using BITS_PER_LONG, compilers
are smart enough to figure this by themselves.

v2: fixed a clang W=1 (-Wtautological-constant-out-of-range-compare) warning
    (Jakub)

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
