linux-stable.git/include/net, branch v6.18.4 Linux kernel stable tree net: dsa: properly keep track of conduit reference 2026-01-08T09:16:45+00:00 Vladimir Oltean vladimir.oltean@nxp.com 2025-12-15T15:02:35+00:00 0e766b77ba5093583dfe609fae0aa1545c46dbbd [ Upstream commit 06e219f6a706c367c93051f408ac61417643d2f9 ] Problem description ------------------- DSA has a mumbo-jumbo of reference handling of the conduit net device and its kobject which, sadly, is just wrong and doesn't make sense. There are two distinct problems. 1. The OF path, which uses of_find_net_device_by_node(), never releases the elevated refcount on the conduit's kobject. Nominally, the OF and non-OF paths should result in objects having identical reference counts taken, and it is already suspicious that dsa_dev_to_net_device() has a put_device() call which is missing in dsa_port_parse_of(), but we can actually even verify that an issue exists. With CONFIG_DEBUG_KOBJECT_RELEASE=y, if we run this command "before" and "after" applying this patch: (unbind the conduit driver for net device eno2) echo 0000:00:00.2 > /sys/bus/pci/drivers/fsl_enetc/unbind we see these lines in the output diff which appear only with the patch applied: kobject: 'eno2' (ffff002009a3a6b8): kobject_release, parent 0000000000000000 (delayed 1000) kobject: '109' (ffff0020099d59a0): kobject_release, parent 0000000000000000 (delayed 1000) 2. After we find the conduit interface one way (OF) or another (non-OF), it can get unregistered at any time, and DSA remains with a long-lived, but in this case stale, cpu_dp->conduit pointer. Holding the net device's underlying kobject isn't actually of much help, it just prevents it from being freed (but we never need that kobject directly). What helps us to prevent the net device from being unregistered is the parallel netdev reference mechanism (dev_hold() and dev_put()). Actually we actually use that netdev tracker mechanism implicitly on user ports since commit 2f1e8ea726e9 ("net: dsa: link interfaces with the DSA master to get rid of lockdep warnings"), via netdev_upper_dev_link(). But time still passes at DSA switch probe time between the initial of_find_net_device_by_node() code and the user port creation time, time during which the conduit could unregister itself and DSA wouldn't know about it. So we have to run of_find_net_device_by_node() under rtnl_lock() to prevent that from happening, and release the lock only with the netdev tracker having acquired the reference. Do we need to keep the reference until dsa_unregister_switch() / dsa_switch_shutdown()? 1: Maybe yes. A switch device will still be registered even if all user ports failed to probe, see commit 86f8b1c01a0a ("net: dsa: Do not make user port errors fatal"), and the cpu_dp->conduit pointers remain valid. I haven't audited all call paths to see whether they will actually use the conduit in lack of any user port, but if they do, it seems safer to not rely on user ports for that reference. 2. Definitely yes. We support changing the conduit which a user port is associated to, and we can get into a situation where we've moved all user ports away from a conduit, thus no longer hold any reference to it via the net device tracker. But we shouldn't let it go nonetheless - see the next change in relation to dsa_tree_find_first_conduit() and LAG conduits which disappear. We have to be prepared to return to the physical conduit, so the CPU port must explicitly keep another reference to it. This is also to say: the user ports and their CPU ports may not always keep a reference to the same conduit net device, and both are needed. As for the conduit's kobject for the /sys/class/net/ entry, we don't care about it, we can release it as soon as we hold the net device object itself. History and blame attribution ----------------------------- The code has been refactored so many times, it is very difficult to follow and properly attribute a blame, but I'll try to make a short history which I hope to be correct. We have two distinct probing paths: - one for OF, introduced in 2016 in commit 83c0afaec7b7 ("net: dsa: Add new binding implementation") - one for non-OF, introduced in 2017 in commit 71e0bbde0d88 ("net: dsa: Add support for platform data") These are both complete rewrites of the original probing paths (which used struct dsa_switch_driver and other weird stuff, instead of regular devices on their respective buses for register access, like MDIO, SPI, I2C etc): - one for OF, introduced in 2013 in commit 5e95329b701c ("dsa: add device tree bindings to register DSA switches") - one for non-OF, introduced in 2008 in commit 91da11f870f0 ("net: Distributed Switch Architecture protocol support") except for tiny bits and pieces like dsa_dev_to_net_device() which were seemingly carried over since the original commit, and used to this day. The point is that the original probing paths received a fix in 2015 in the form of commit 679fb46c5785 ("net: dsa: Add missing master netdev dev_put() calls"), but the fix never made it into the "new" (dsa2) probing paths that can still be traced to today, and the fixed probing path was later deleted in 2019 in commit 93e86b3bc842 ("net: dsa: Remove legacy probing support"). That is to say, the new probing paths were never quite correct in this area. The existence of the legacy probing support which was deleted in 2019 explains why dsa_dev_to_net_device() returns a conduit with elevated refcount (because it was supposed to be released during dsa_remove_dst()). After the removal of the legacy code, the only user of dsa_dev_to_net_device() calls dev_put(conduit) immediately after this function returns. This pattern makes no sense today, and can only be interpreted historically to understand why dev_hold() was there in the first place. Change details -------------- Today we have a better netdev tracking infrastructure which we should use. Logically netdev_hold() belongs in common code (dsa_port_parse_cpu(), where dp->conduit is assigned), but there is a tradeoff to be made with the rtnl_lock() section which would become a bit too long if we did that - dsa_port_parse_cpu() also calls request_module(). So we duplicate a bit of logic in order for the callers of dsa_port_parse_cpu() to be the ones responsible of holding the conduit reference and releasing it on error. This shortens the rtnl_lock() section significantly. In the dsa_switch_probe() error path, dsa_switch_release_ports() will be called in a number of situations, one being where dsa_port_parse_cpu() maybe didn't get the chance to run at all (a different port failed earlier, etc). So we have to test for the conduit being NULL prior to calling netdev_put(). There have still been so many transformations to the code since the blamed commits (rename master -> conduit, commit 0650bf52b31f ("net: dsa: be compatible with masters which unregister on shutdown")), that it only makes sense to fix the code using the best methods available today and see how it can be backported to stable later. I suspect the fix cannot even be backported to kernels which lack dsa_switch_shutdown(), and I suspect this is also maybe why the long-lived conduit reference didn't make it into the new DSA probing paths at the time (problems during shutdown). Because dsa_dev_to_net_device() has a single call site and has to be changed anyway, the logic was just absorbed into the non-OF dsa_port_parse(). Tested on the ocelot/felix switch and on dsa_loop, both on the NXP LS1028A with CONFIG_DEBUG_KOBJECT_RELEASE=y. Reported-by: Ma Ke <make24@iscas.ac.cn> Closes: https://lore.kernel.org/netdev/20251214131204.4684-1-make24@iscas.ac.cn/ Fixes: 83c0afaec7b7 ("net: dsa: Add new binding implementation") Fixes: 71e0bbde0d88 ("net: dsa: Add support for platform data") Reviewed-by: Jonas Gorski <jonas.gorski@gmail.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://patch.msgid.link/20251215150236.3931670-1-vladimir.oltean@nxp.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 06e219f6a706c367c93051f408ac61417643d2f9 ]

Problem description
-------------------

DSA has a mumbo-jumbo of reference handling of the conduit net device
and its kobject which, sadly, is just wrong and doesn't make sense.

There are two distinct problems.

1. The OF path, which uses of_find_net_device_by_node(), never releases
   the elevated refcount on the conduit's kobject. Nominally, the OF and
   non-OF paths should result in objects having identical reference
   counts taken, and it is already suspicious that
   dsa_dev_to_net_device() has a put_device() call which is missing in
   dsa_port_parse_of(), but we can actually even verify that an issue
   exists. With CONFIG_DEBUG_KOBJECT_RELEASE=y, if we run this command
   "before" and "after" applying this patch:

(unbind the conduit driver for net device eno2)
echo 0000:00:00.2 > /sys/bus/pci/drivers/fsl_enetc/unbind

we see these lines in the output diff which appear only with the patch
applied:

kobject: 'eno2' (ffff002009a3a6b8): kobject_release, parent 0000000000000000 (delayed 1000)
kobject: '109' (ffff0020099d59a0): kobject_release, parent 0000000000000000 (delayed 1000)

2. After we find the conduit interface one way (OF) or another (non-OF),
   it can get unregistered at any time, and DSA remains with a long-lived,
   but in this case stale, cpu_dp->conduit pointer. Holding the net
   device's underlying kobject isn't actually of much help, it just
   prevents it from being freed (but we never need that kobject
   directly). What helps us to prevent the net device from being
   unregistered is the parallel netdev reference mechanism (dev_hold()
   and dev_put()).

Actually we actually use that netdev tracker mechanism implicitly on
user ports since commit 2f1e8ea726e9 ("net: dsa: link interfaces with
the DSA master to get rid of lockdep warnings"), via netdev_upper_dev_link().
But time still passes at DSA switch probe time between the initial
of_find_net_device_by_node() code and the user port creation time, time
during which the conduit could unregister itself and DSA wouldn't know
about it.

So we have to run of_find_net_device_by_node() under rtnl_lock() to
prevent that from happening, and release the lock only with the netdev
tracker having acquired the reference.

Do we need to keep the reference until dsa_unregister_switch() /
dsa_switch_shutdown()?
1: Maybe yes. A switch device will still be registered even if all user
   ports failed to probe, see commit 86f8b1c01a0a ("net: dsa: Do not
   make user port errors fatal"), and the cpu_dp->conduit pointers
   remain valid.  I haven't audited all call paths to see whether they
   will actually use the conduit in lack of any user port, but if they
   do, it seems safer to not rely on user ports for that reference.
2. Definitely yes. We support changing the conduit which a user port is
   associated to, and we can get into a situation where we've moved all
   user ports away from a conduit, thus no longer hold any reference to
   it via the net device tracker. But we shouldn't let it go nonetheless
   - see the next change in relation to dsa_tree_find_first_conduit()
   and LAG conduits which disappear.
   We have to be prepared to return to the physical conduit, so the CPU
   port must explicitly keep another reference to it. This is also to
   say: the user ports and their CPU ports may not always keep a
   reference to the same conduit net device, and both are needed.

As for the conduit's kobject for the /sys/class/net/ entry, we don't
care about it, we can release it as soon as we hold the net device
object itself.

History and blame attribution
-----------------------------

The code has been refactored so many times, it is very difficult to
follow and properly attribute a blame, but I'll try to make a short
history which I hope to be correct.

We have two distinct probing paths:
- one for OF, introduced in 2016 in commit 83c0afaec7b7 ("net: dsa: Add
  new binding implementation")
- one for non-OF, introduced in 2017 in commit 71e0bbde0d88 ("net: dsa:
  Add support for platform data")

These are both complete rewrites of the original probing paths (which
used struct dsa_switch_driver and other weird stuff, instead of regular
devices on their respective buses for register access, like MDIO, SPI,
I2C etc):
- one for OF, introduced in 2013 in commit 5e95329b701c ("dsa: add
  device tree bindings to register DSA switches")
- one for non-OF, introduced in 2008 in commit 91da11f870f0 ("net:
  Distributed Switch Architecture protocol support")

except for tiny bits and pieces like dsa_dev_to_net_device() which were
seemingly carried over since the original commit, and used to this day.

The point is that the original probing paths received a fix in 2015 in
the form of commit 679fb46c5785 ("net: dsa: Add missing master netdev
dev_put() calls"), but the fix never made it into the "new" (dsa2)
probing paths that can still be traced to today, and the fixed probing
path was later deleted in 2019 in commit 93e86b3bc842 ("net: dsa: Remove
legacy probing support").

That is to say, the new probing paths were never quite correct in this
area.

The existence of the legacy probing support which was deleted in 2019
explains why dsa_dev_to_net_device() returns a conduit with elevated
refcount (because it was supposed to be released during
dsa_remove_dst()). After the removal of the legacy code, the only user
of dsa_dev_to_net_device() calls dev_put(conduit) immediately after this
function returns. This pattern makes no sense today, and can only be
interpreted historically to understand why dev_hold() was there in the
first place.

Change details
--------------

Today we have a better netdev tracking infrastructure which we should
use. Logically netdev_hold() belongs in common code
(dsa_port_parse_cpu(), where dp->conduit is assigned), but there is a
tradeoff to be made with the rtnl_lock() section which would become a
bit too long if we did that - dsa_port_parse_cpu() also calls
request_module(). So we duplicate a bit of logic in order for the
callers of dsa_port_parse_cpu() to be the ones responsible of holding
the conduit reference and releasing it on error. This shortens the
rtnl_lock() section significantly.

In the dsa_switch_probe() error path, dsa_switch_release_ports() will be
called in a number of situations, one being where dsa_port_parse_cpu()
maybe didn't get the chance to run at all (a different port failed
earlier, etc). So we have to test for the conduit being NULL prior to
calling netdev_put().

There have still been so many transformations to the code since the
blamed commits (rename master -> conduit, commit 0650bf52b31f ("net:
dsa: be compatible with masters which unregister on shutdown")), that it
only makes sense to fix the code using the best methods available today
and see how it can be backported to stable later. I suspect the fix
cannot even be backported to kernels which lack dsa_switch_shutdown(),
and I suspect this is also maybe why the long-lived conduit reference
didn't make it into the new DSA probing paths at the time (problems
during shutdown).

Because dsa_dev_to_net_device() has a single call site and has to be
changed anyway, the logic was just absorbed into the non-OF
dsa_port_parse().

Tested on the ocelot/felix switch and on dsa_loop, both on the NXP
LS1028A with CONFIG_DEBUG_KOBJECT_RELEASE=y.

Reported-by: Ma Ke <make24@iscas.ac.cn>
Closes: https://lore.kernel.org/netdev/20251214131204.4684-1-make24@iscas.ac.cn/
Fixes: 83c0afaec7b7 ("net: dsa: Add new binding implementation")
Fixes: 71e0bbde0d88 ("net: dsa: Add support for platform data")
Reviewed-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20251215150236.3931670-1-vladimir.oltean@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
inet: frags: flush pending skbs in fqdir_pre_exit() 2026-01-02T11:56:46+00:00 Jakub Kicinski kuba@kernel.org 2025-12-07T01:09:41+00:00 c70df25214ac9b32b53e18e6ae3b8f073ffa6903 [ Upstream commit 006a5035b495dec008805df249f92c22c89c3d2e ] We have been seeing occasional deadlocks on pernet_ops_rwsem since September in NIPA. The stuck task was usually modprobe (often loading a driver like ipvlan), trying to take the lock as a Writer. lockdep does not track readers for rwsems so the read wasn't obvious from the reports. On closer inspection the Reader holding the lock was conntrack looping forever in nf_conntrack_cleanup_net_list(). Based on past experience with occasional NIPA crashes I looked thru the tests which run before the crash and noticed that the crash follows ip_defrag.sh. An immediate red flag. Scouring thru (de)fragmentation queues reveals skbs sitting around, holding conntrack references. The problem is that since conntrack depends on nf_defrag_ipv6, nf_defrag_ipv6 will load first. Since nf_defrag_ipv6 loads first its netns exit hooks run _after_ conntrack's netns exit hook. Flush all fragment queue SKBs during fqdir_pre_exit() to release conntrack references before conntrack cleanup runs. Also flush the queues in timer expiry handlers when they discover fqdir->dead is set, in case packet sneaks in while we're running the pre_exit flush. The commit under Fixes is not exactly the culprit, but I think previously the timer firing would eventually unblock the spinning conntrack. Fixes: d5dd88794a13 ("inet: fix various use-after-free in defrags units") Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251207010942.1672972-4-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 006a5035b495dec008805df249f92c22c89c3d2e ]

We have been seeing occasional deadlocks on pernet_ops_rwsem since
September in NIPA. The stuck task was usually modprobe (often loading
a driver like ipvlan), trying to take the lock as a Writer.
lockdep does not track readers for rwsems so the read wasn't obvious
from the reports.

On closer inspection the Reader holding the lock was conntrack looping
forever in nf_conntrack_cleanup_net_list(). Based on past experience
with occasional NIPA crashes I looked thru the tests which run before
the crash and noticed that the crash follows ip_defrag.sh. An immediate
red flag. Scouring thru (de)fragmentation queues reveals skbs sitting
around, holding conntrack references.

The problem is that since conntrack depends on nf_defrag_ipv6,
nf_defrag_ipv6 will load first. Since nf_defrag_ipv6 loads first its
netns exit hooks run _after_ conntrack's netns exit hook.

Flush all fragment queue SKBs during fqdir_pre_exit() to release
conntrack references before conntrack cleanup runs. Also flush
the queues in timer expiry handlers when they discover fqdir->dead
is set, in case packet sneaks in while we're running the pre_exit
flush.

The commit under Fixes is not exactly the culprit, but I think
previously the timer firing would eventually unblock the spinning
conntrack.

Fixes: d5dd88794a13 ("inet: fix various use-after-free in defrags units")
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251207010942.1672972-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
inet: frags: add inet_frag_queue_flush() 2026-01-02T11:56:46+00:00 Jakub Kicinski kuba@kernel.org 2025-12-07T01:09:40+00:00 58e7108971fa61f280590903223a2ced65a1e942 [ Upstream commit 1231eec6994be29d6bb5c303dfa54731ed9fc0e6 ] Instead of exporting inet_frag_rbtree_purge() which requires that caller takes care of memory accounting, add a new helper. We will need to call it from a few places in the next patch. Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251207010942.1672972-3-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 006a5035b495 ("inet: frags: flush pending skbs in fqdir_pre_exit()") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1231eec6994be29d6bb5c303dfa54731ed9fc0e6 ]

Instead of exporting inet_frag_rbtree_purge() which requires that
caller takes care of memory accounting, add a new helper. We will
need to call it from a few places in the next patch.

Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251207010942.1672972-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 006a5035b495 ("inet: frags: flush pending skbs in fqdir_pre_exit()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
netfilter: nf_conncount: rework API to use sk_buff directly 2025-12-18T13:03:26+00:00 Fernando Fernandez Mancera fmancera@suse.de 2025-11-21T00:14:30+00:00 f6904ed15ed1a188543057e3cb0d02daa80edfc9 [ Upstream commit be102eb6a0e7c03db00e50540622f4e43b2d2844 ] When using nf_conncount infrastructure for non-confirmed connections a duplicated track is possible due to an optimization introduced since commit d265929930e2 ("netfilter: nf_conncount: reduce unnecessary GC"). In order to fix this introduce a new conncount API that receives directly an sk_buff struct. It fetches the tuple and zone and the corresponding ct from it. It comes with both existing conncount variants nf_conncount_count_skb() and nf_conncount_add_skb(). In addition remove the old API and adjust all the users to use the new one. This way, for each sk_buff struct it is possible to check if there is a ct present and already confirmed. If so, skip the add operation. Fixes: d265929930e2 ("netfilter: nf_conncount: reduce unnecessary GC") Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit be102eb6a0e7c03db00e50540622f4e43b2d2844 ]

When using nf_conncount infrastructure for non-confirmed connections a
duplicated track is possible due to an optimization introduced since
commit d265929930e2 ("netfilter: nf_conncount: reduce unnecessary GC").

In order to fix this introduce a new conncount API that receives
directly an sk_buff struct.  It fetches the tuple and zone and the
corresponding ct from it. It comes with both existing conncount variants
nf_conncount_count_skb() and nf_conncount_add_skb(). In addition remove
the old API and adjust all the users to use the new one.

This way, for each sk_buff struct it is possible to check if there is a
ct present and already confirmed. If so, skip the add operation.

Fixes: d265929930e2 ("netfilter: nf_conncount: reduce unnecessary GC")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: sched: fix TCF_LAYER_TRANSPORT handling in tcf_get_base_ptr() 2025-11-25T02:53:14+00:00 Eric Dumazet edumazet@google.com 2025-11-21T15:41:00+00:00 4fe5a00ec70717a7f1002d8913ec6143582b3c8e syzbot reported that tcf_get_base_ptr() can be called while transport header is not set [1]. Instead of returning a dangling pointer, return NULL. Fix tcf_get_base_ptr() callers to handle this NULL value. [1] WARNING: CPU: 1 PID: 6019 at ./include/linux/skbuff.h:3071 skb_transport_header include/linux/skbuff.h:3071 [inline] WARNING: CPU: 1 PID: 6019 at ./include/linux/skbuff.h:3071 tcf_get_base_ptr include/net/pkt_cls.h:539 [inline] WARNING: CPU: 1 PID: 6019 at ./include/linux/skbuff.h:3071 em_nbyte_match+0x2d8/0x3f0 net/sched/em_nbyte.c:43 Modules linked in: CPU: 1 UID: 0 PID: 6019 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Call Trace: <TASK> tcf_em_match net/sched/ematch.c:494 [inline] __tcf_em_tree_match+0x1ac/0x770 net/sched/ematch.c:520 tcf_em_tree_match include/net/pkt_cls.h:512 [inline] basic_classify+0x115/0x2d0 net/sched/cls_basic.c:50 tc_classify include/net/tc_wrapper.h:197 [inline] __tcf_classify net/sched/cls_api.c:1764 [inline] tcf_classify+0x4cf/0x1140 net/sched/cls_api.c:1860 multiq_classify net/sched/sch_multiq.c:39 [inline] multiq_enqueue+0xfd/0x4c0 net/sched/sch_multiq.c:66 dev_qdisc_enqueue+0x4e/0x260 net/core/dev.c:4118 __dev_xmit_skb net/core/dev.c:4214 [inline] __dev_queue_xmit+0xe83/0x3b50 net/core/dev.c:4729 packet_snd net/packet/af_packet.c:3076 [inline] packet_sendmsg+0x3e33/0x5080 net/packet/af_packet.c:3108 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x830 net/socket.c:2630 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+f3a497f02c389d86ef16@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6920855a.a70a0220.2ea503.0058.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://patch.msgid.link/20251121154100.1616228-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
syzbot reported that tcf_get_base_ptr() can be called while transport
header is not set [1].

Instead of returning a dangling pointer, return NULL.

Fix tcf_get_base_ptr() callers to handle this NULL value.

[1]
 WARNING: CPU: 1 PID: 6019 at ./include/linux/skbuff.h:3071 skb_transport_header include/linux/skbuff.h:3071 [inline]
 WARNING: CPU: 1 PID: 6019 at ./include/linux/skbuff.h:3071 tcf_get_base_ptr include/net/pkt_cls.h:539 [inline]
 WARNING: CPU: 1 PID: 6019 at ./include/linux/skbuff.h:3071 em_nbyte_match+0x2d8/0x3f0 net/sched/em_nbyte.c:43
Modules linked in:
CPU: 1 UID: 0 PID: 6019 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Call Trace:
 <TASK>
  tcf_em_match net/sched/ematch.c:494 [inline]
  __tcf_em_tree_match+0x1ac/0x770 net/sched/ematch.c:520
  tcf_em_tree_match include/net/pkt_cls.h:512 [inline]
  basic_classify+0x115/0x2d0 net/sched/cls_basic.c:50
  tc_classify include/net/tc_wrapper.h:197 [inline]
  __tcf_classify net/sched/cls_api.c:1764 [inline]
  tcf_classify+0x4cf/0x1140 net/sched/cls_api.c:1860
  multiq_classify net/sched/sch_multiq.c:39 [inline]
  multiq_enqueue+0xfd/0x4c0 net/sched/sch_multiq.c:66
  dev_qdisc_enqueue+0x4e/0x260 net/core/dev.c:4118
  __dev_xmit_skb net/core/dev.c:4214 [inline]
  __dev_queue_xmit+0xe83/0x3b50 net/core/dev.c:4729
  packet_snd net/packet/af_packet.c:3076 [inline]
  packet_sendmsg+0x3e33/0x5080 net/packet/af_packet.c:3108
  sock_sendmsg_nosec net/socket.c:727 [inline]
  __sock_sendmsg+0x21c/0x270 net/socket.c:742
  ____sys_sendmsg+0x505/0x830 net/socket.c:2630

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+f3a497f02c389d86ef16@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6920855a.a70a0220.2ea503.0058.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20251121154100.1616228-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Bluetooth: hci_core: lookup hci_conn on RX path on protocol side 2025-11-20T22:01:09+00:00 Pauli Virtanen pav@iki.fi 2025-11-15T16:43:55+00:00 79a2d4678ba90bdba577dc3af88cc900d6dcd5ee The hdev lock/lookup/unlock/use pattern in the packet RX path doesn't ensure hci_conn* is not concurrently modified/deleted. This locking appears to be leftover from before conn_hash started using RCU commit bf4c63252490b ("Bluetooth: convert conn hash to RCU") and not clear if it had purpose since then. Currently, there are code paths that delete hci_conn* from elsewhere than the ordered hdev->workqueue where the RX work runs in. E.g. commit 5af1f84ed13a ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync") introduced some of these, and there probably were a few others before it. It's better to do the locking so that even if these run concurrently no UAF is possible. Move the lookup of hci_conn and associated socket-specific conn to protocol recv handlers, and do them within a single critical section to cover hci_conn* usage and lookup. syzkaller has reported a crash that appears to be this issue: [Task hdev->workqueue] [Task 2] hci_disconnect_all_sync l2cap_recv_acldata(hcon) hci_conn_get(hcon) hci_abort_conn_sync(hcon) hci_dev_lock hci_dev_lock hci_conn_del(hcon) v-------------------------------- hci_dev_unlock hci_conn_put(hcon) conn = hcon->l2cap_data (UAF) Fixes: 5af1f84ed13a ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync") Reported-by: syzbot+d32d77220b92eddd89ad@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d32d77220b92eddd89ad Signed-off-by: Pauli Virtanen <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> 
The hdev lock/lookup/unlock/use pattern in the packet RX path doesn't
ensure hci_conn* is not concurrently modified/deleted. This locking
appears to be leftover from before conn_hash started using RCU
commit bf4c63252490b ("Bluetooth: convert conn hash to RCU")
and not clear if it had purpose since then.

Currently, there are code paths that delete hci_conn* from elsewhere
than the ordered hdev->workqueue where the RX work runs in. E.g.
commit 5af1f84ed13a ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync")
introduced some of these, and there probably were a few others before
it.  It's better to do the locking so that even if these run
concurrently no UAF is possible.

Move the lookup of hci_conn and associated socket-specific conn to
protocol recv handlers, and do them within a single critical section
to cover hci_conn* usage and lookup.

syzkaller has reported a crash that appears to be this issue:

    [Task hdev->workqueue]          [Task 2]
                                    hci_disconnect_all_sync
    l2cap_recv_acldata(hcon)
                                      hci_conn_get(hcon)
                                      hci_abort_conn_sync(hcon)
                                        hci_dev_lock
      hci_dev_lock
                                        hci_conn_del(hcon)
      v-------------------------------- hci_dev_unlock
                                      hci_conn_put(hcon)
      conn = hcon->l2cap_data (UAF)

Fixes: 5af1f84ed13a ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync")
Reported-by: syzbot+d32d77220b92eddd89ad@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=d32d77220b92eddd89ad
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Bluetooth: btusb: mediatek: Fix kernel crash when releasing mtk iso interface 2025-11-20T21:51:14+00:00 Chris Lu chris.lu@mediatek.com 2025-11-12T07:53:34+00:00 4015b979767125cf8a2233a145a3b3af78bfd8fb When performing reset tests and encountering abnormal card drop issues that lead to a kernel crash, it is necessary to perform a null check before releasing resources to avoid attempting to release a null pointer. <4>[ 29.158070] Hardware name: Google Quigon sku196612/196613 board (DT) <4>[ 29.158076] Workqueue: hci0 hci_cmd_sync_work [bluetooth] <4>[ 29.158154] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) <4>[ 29.158162] pc : klist_remove+0x90/0x158 <4>[ 29.158174] lr : klist_remove+0x88/0x158 <4>[ 29.158180] sp : ffffffc0846b3c00 <4>[ 29.158185] pmr_save: 000000e0 <4>[ 29.158188] x29: ffffffc0846b3c30 x28: ffffff80cd31f880 x27: ffffff80c1bdc058 <4>[ 29.158199] x26: dead000000000100 x25: ffffffdbdc624ea3 x24: ffffff80c1bdc4c0 <4>[ 29.158209] x23: ffffffdbdc62a3e6 x22: ffffff80c6c07000 x21: ffffffdbdc829290 <4>[ 29.158219] x20: 0000000000000000 x19: ffffff80cd3e0648 x18: 000000031ec97781 <4>[ 29.158229] x17: ffffff80c1bdc4a8 x16: ffffffdc10576548 x15: ffffff80c1180428 <4>[ 29.158238] x14: 0000000000000000 x13: 000000000000e380 x12: 0000000000000018 <4>[ 29.158248] x11: ffffff80c2a7fd10 x10: 0000000000000000 x9 : 0000000100000000 <4>[ 29.158257] x8 : 0000000000000000 x7 : 7f7f7f7f7f7f7f7f x6 : 2d7223ff6364626d <4>[ 29.158266] x5 : 0000008000000000 x4 : 0000000000000020 x3 : 2e7325006465636e <4>[ 29.158275] x2 : ffffffdc11afeff8 x1 : 0000000000000000 x0 : ffffffdc11be4d0c <4>[ 29.158285] Call trace: <4>[ 29.158290] klist_remove+0x90/0x158 <4>[ 29.158298] device_release_driver_internal+0x20c/0x268 <4>[ 29.158308] device_release_driver+0x1c/0x30 <4>[ 29.158316] usb_driver_release_interface+0x70/0x88 <4>[ 29.158325] btusb_mtk_release_iso_intf+0x68/0xd8 [btusb (HASH:e8b6 5)] <4>[ 29.158347] btusb_mtk_reset+0x5c/0x480 [btusb (HASH:e8b6 5)] <4>[ 29.158361] hci_cmd_sync_work+0x10c/0x188 [bluetooth (HASH:a4fa 6)] <4>[ 29.158430] process_scheduled_works+0x258/0x4e8 <4>[ 29.158441] worker_thread+0x300/0x428 <4>[ 29.158448] kthread+0x108/0x1d0 <4>[ 29.158455] ret_from_fork+0x10/0x20 <0>[ 29.158467] Code: 91343000 940139d1 f9400268 927ff914 (f9401297) <4>[ 29.158474] ---[ end trace 0000000000000000 ]--- <0>[ 29.167129] Kernel panic - not syncing: Oops: Fatal exception <2>[ 29.167144] SMP: stopping secondary CPUs <4>[ 29.167158] ------------[ cut here ]------------ Fixes: ceac1cb0259d ("Bluetooth: btusb: mediatek: add ISO data transmission functions") Signed-off-by: Chris Lu <chris.lu@mediatek.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> 
When performing reset tests and encountering abnormal card drop issues
that lead to a kernel crash, it is necessary to perform a null check
before releasing resources to avoid attempting to release a null pointer.

<4>[   29.158070] Hardware name: Google Quigon sku196612/196613 board (DT)
<4>[   29.158076] Workqueue: hci0 hci_cmd_sync_work [bluetooth]
<4>[   29.158154] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
<4>[   29.158162] pc : klist_remove+0x90/0x158
<4>[   29.158174] lr : klist_remove+0x88/0x158
<4>[   29.158180] sp : ffffffc0846b3c00
<4>[   29.158185] pmr_save: 000000e0
<4>[   29.158188] x29: ffffffc0846b3c30 x28: ffffff80cd31f880 x27: ffffff80c1bdc058
<4>[   29.158199] x26: dead000000000100 x25: ffffffdbdc624ea3 x24: ffffff80c1bdc4c0
<4>[   29.158209] x23: ffffffdbdc62a3e6 x22: ffffff80c6c07000 x21: ffffffdbdc829290
<4>[   29.158219] x20: 0000000000000000 x19: ffffff80cd3e0648 x18: 000000031ec97781
<4>[   29.158229] x17: ffffff80c1bdc4a8 x16: ffffffdc10576548 x15: ffffff80c1180428
<4>[   29.158238] x14: 0000000000000000 x13: 000000000000e380 x12: 0000000000000018
<4>[   29.158248] x11: ffffff80c2a7fd10 x10: 0000000000000000 x9 : 0000000100000000
<4>[   29.158257] x8 : 0000000000000000 x7 : 7f7f7f7f7f7f7f7f x6 : 2d7223ff6364626d
<4>[   29.158266] x5 : 0000008000000000 x4 : 0000000000000020 x3 : 2e7325006465636e
<4>[   29.158275] x2 : ffffffdc11afeff8 x1 : 0000000000000000 x0 : ffffffdc11be4d0c
<4>[   29.158285] Call trace:
<4>[   29.158290]  klist_remove+0x90/0x158
<4>[   29.158298]  device_release_driver_internal+0x20c/0x268
<4>[   29.158308]  device_release_driver+0x1c/0x30
<4>[   29.158316]  usb_driver_release_interface+0x70/0x88
<4>[   29.158325]  btusb_mtk_release_iso_intf+0x68/0xd8 [btusb (HASH:e8b6 5)]
<4>[   29.158347]  btusb_mtk_reset+0x5c/0x480 [btusb (HASH:e8b6 5)]
<4>[   29.158361]  hci_cmd_sync_work+0x10c/0x188 [bluetooth (HASH:a4fa 6)]
<4>[   29.158430]  process_scheduled_works+0x258/0x4e8
<4>[   29.158441]  worker_thread+0x300/0x428
<4>[   29.158448]  kthread+0x108/0x1d0
<4>[   29.158455]  ret_from_fork+0x10/0x20
<0>[   29.158467] Code: 91343000 940139d1 f9400268 927ff914 (f9401297)
<4>[   29.158474] ---[ end trace 0000000000000000 ]---
<0>[   29.167129] Kernel panic - not syncing: Oops: Fatal exception
<2>[   29.167144] SMP: stopping secondary CPUs
<4>[   29.167158] ------------[ cut here ]------------

Fixes: ceac1cb0259d ("Bluetooth: btusb: mediatek: add ISO data transmission functions")
Signed-off-by: Chris Lu <chris.lu@mediatek.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Merge tag 'ipsec-2025-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec 2025-11-19T01:58:44+00:00 Jakub Kicinski kuba@kernel.org 2025-11-19T01:58:44+00:00 c3995fc1a89cc716bfe914c829b84da879c11db4 Steffen Klassert says: ==================== pull request (net): ipsec 2025-11-18 1) Misc fixes for xfrm_state creation/modification/deletion. Patchset from Sabrina Dubroca. 2) Fix inner packet family determination for xfrm offloads. From Jianbo Liu. 3) Don't push locally generated packets directly to L2 tunnel mode offloading, they still need processing from the standard xfrm path. From Jianbo Liu. 4) Fix memory leaks in xfrm_add_acquire for policy offloads and policy security contexts. From Zilin Guan. * tag 'ipsec-2025-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: xfrm: fix memory leak in xfrm_add_acquire() xfrm: Prevent locally generated packets from direct output in tunnel mode xfrm: Determine inner GSO type from packet inner protocol xfrm: Check inner packet family directly from skb_dst xfrm: check all hash buckets for leftover states during netns deletion xfrm: set err and extack on failure to create pcpu SA xfrm: call xfrm_dev_state_delete when xfrm_state_migrate fails to add the state xfrm: make state as DEAD before final put when migrate fails xfrm: also call xfrm_state_delete_tunnel at destroy time for states that were never added xfrm: drop SA reference in xfrm_state_update if dir doesn't match ==================== Link: https://patch.msgid.link/20251118085344.2199815-1-steffen.klassert@secunet.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Steffen Klassert says:

====================
pull request (net): ipsec 2025-11-18

1) Misc fixes for xfrm_state creation/modification/deletion.
   Patchset from Sabrina Dubroca.

2) Fix inner packet family determination for xfrm offloads.
   From Jianbo Liu.

3) Don't push locally generated packets directly to L2 tunnel
   mode offloading, they still need processing from the standard
   xfrm path. From Jianbo Liu.

4) Fix memory leaks in xfrm_add_acquire for policy offloads and policy
   security contexts. From Zilin Guan.

* tag 'ipsec-2025-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec:
  xfrm: fix memory leak in xfrm_add_acquire()
  xfrm: Prevent locally generated packets from direct output in tunnel mode
  xfrm: Determine inner GSO type from packet inner protocol
  xfrm: Check inner packet family directly from skb_dst
  xfrm: check all hash buckets for leftover states during netns deletion
  xfrm: set err and extack on failure to create pcpu SA
  xfrm: call xfrm_dev_state_delete when xfrm_state_migrate fails to add the state
  xfrm: make state as DEAD before final put when migrate fails
  xfrm: also call xfrm_state_delete_tunnel at destroy time for states that were never added
  xfrm: drop SA reference in xfrm_state_update if dir doesn't match
====================

Link: https://patch.msgid.link/20251118085344.2199815-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Merge tag 'net-6.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-11-13T19:20:25+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-11-13T19:20:25+00:00 d0309c054362a235077327b46f727bc48878a3bc Pull networking fixes from Paolo Abeni: "Including fixes from Bluetooth and Wireless. No known outstanding regressions. Current release - regressions: - eth: - bonding: fix mii_status when slave is down - mlx5e: fix missing error assignment in mlx5e_xfrm_add_state() Previous releases - regressions: - sched: limit try_bulk_dequeue_skb() batches - ipv4: route: prevent rt_bind_exception() from rebinding stale fnhe - af_unix: initialise scc_index in unix_add_edge() - netpoll: fix incorrect refcount handling causing incorrect cleanup - bluetooth: don't hold spin lock over sleeping functions - hsr: Fix supervision frame sending on HSRv0 - sctp: prevent possible shift out-of-bounds - tipc: fix use-after-free in tipc_mon_reinit_self(). - dsa: tag_brcm: do not mark link local traffic as offloaded - eth: virtio-net: fix incorrect flags recording in big mode Previous releases - always broken: - sched: initialize struct tc_ife to fix kernel-infoleak - wifi: - mac80211: reject address change while connecting - iwlwifi: avoid toggling links due to wrong element use - bluetooth: cancel mesh send timer when hdev removed - strparser: fix signed/unsigned mismatch bug - handshake: fix memory leak in tls_handshake_accept() Misc: - selftests: mptcp: fix some flaky tests" * tag 'net-6.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (60 commits) hsr: Follow standard for HSRv0 supervision frames hsr: Fix supervision frame sending on HSRv0 virtio-net: fix incorrect flags recording in big mode ipv4: route: Prevent rt_bind_exception() from rebinding stale fnhe wifi: iwlwifi: mld: always take beacon ies in link grading wifi: iwlwifi: mvm: fix beacon template/fixed rate wifi: iwlwifi: fix aux ROC time event iterator usage net_sched: limit try_bulk_dequeue_skb() batches selftests: mptcp: join: properly kill background tasks selftests: mptcp: connect: trunc: read all recv data selftests: mptcp: join: userspace: longer transfer selftests: mptcp: join: endpoints: longer transfer selftests: mptcp: join: rm: set backup flag selftests: mptcp: connect: fix fallback note due to OoO ethtool: fix incorrect kernel-doc style comment in ethtool.h mlx5: Fix default values in create CQ Bluetooth: btrtl: Avoid loading the config file on security chips net/mlx5e: Fix potentially misleading debug message net/mlx5e: Fix wraparound in rate limiting for values above 255 Gbps net/mlx5e: Fix maxrate wraparound in threshold between units ... 
Pull networking fixes from Paolo Abeni:
 "Including fixes from Bluetooth and Wireless. No known outstanding
  regressions.

  Current release - regressions:

   - eth:
      - bonding: fix mii_status when slave is down
      - mlx5e: fix missing error assignment in mlx5e_xfrm_add_state()

  Previous releases - regressions:

   - sched: limit try_bulk_dequeue_skb() batches

   - ipv4: route: prevent rt_bind_exception() from rebinding stale fnhe

   - af_unix: initialise scc_index in unix_add_edge()

   - netpoll: fix incorrect refcount handling causing incorrect cleanup

   - bluetooth: don't hold spin lock over sleeping functions

   - hsr: Fix supervision frame sending on HSRv0

   - sctp: prevent possible shift out-of-bounds

   - tipc: fix use-after-free in tipc_mon_reinit_self().

   - dsa: tag_brcm: do not mark link local traffic as offloaded

   - eth: virtio-net: fix incorrect flags recording in big mode

  Previous releases - always broken:

   - sched: initialize struct tc_ife to fix kernel-infoleak

   - wifi:
      - mac80211: reject address change while connecting
      - iwlwifi: avoid toggling links due to wrong element use

   - bluetooth: cancel mesh send timer when hdev removed

   - strparser: fix signed/unsigned mismatch bug

   - handshake: fix memory leak in tls_handshake_accept()

  Misc:

   - selftests: mptcp: fix some flaky tests"

* tag 'net-6.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (60 commits)
  hsr: Follow standard for HSRv0 supervision frames
  hsr: Fix supervision frame sending on HSRv0
  virtio-net: fix incorrect flags recording in big mode
  ipv4: route: Prevent rt_bind_exception() from rebinding stale fnhe
  wifi: iwlwifi: mld: always take beacon ies in link grading
  wifi: iwlwifi: mvm: fix beacon template/fixed rate
  wifi: iwlwifi: fix aux ROC time event iterator usage
  net_sched: limit try_bulk_dequeue_skb() batches
  selftests: mptcp: join: properly kill background tasks
  selftests: mptcp: connect: trunc: read all recv data
  selftests: mptcp: join: userspace: longer transfer
  selftests: mptcp: join: endpoints: longer transfer
  selftests: mptcp: join: rm: set backup flag
  selftests: mptcp: connect: fix fallback note due to OoO
  ethtool: fix incorrect kernel-doc style comment in ethtool.h
  mlx5: Fix default values in create CQ
  Bluetooth: btrtl: Avoid loading the config file on security chips
  net/mlx5e: Fix potentially misleading debug message
  net/mlx5e: Fix wraparound in rate limiting for values above 255 Gbps
  net/mlx5e: Fix maxrate wraparound in threshold between units
  ...
Bluetooth: hci_event: Fix not handling PA Sync Lost event 2025-11-11T13:55:18+00:00 Luiz Augusto von Dentz luiz.von.dentz@intel.com 2025-11-06T18:05:35+00:00 485e0626e58768f3c53ba61ab9e09d6b60a455f4 This handles PA Sync Lost event which previously was assumed to be handled with BIG Sync Lost but their lifetime are not the same thus why there are 2 different events to inform when each sync is lost. Fixes: b2a5f2e1c127 ("Bluetooth: hci_event: Add support for handling LE BIG Sync Lost event") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> 
This handles PA Sync Lost event which previously was assumed to be
handled with BIG Sync Lost but their lifetime are not the same thus why
there are 2 different events to inform when each sync is lost.

Fixes: b2a5f2e1c127 ("Bluetooth: hci_event: Add support for handling LE BIG Sync Lost event")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>