linux-stable.git/include/net, branch v5.10.261

ipv6: mcast: use rcu-safe version of ipv6_get_lladdr()

2026-07-24T13:49:23+00:00

commit 26394fc118d6115390bd5b3a0fb17096271da227 upstream.

Some time ago 8965779d2c0e ("ipv6,mcast: always hold idev->lock before mca_lock")
switched ipv6_get_lladdr() to __ipv6_get_lladdr(), which is rcu-unsafe
version. That was OK, because idev->lock was held for these codepaths.

In 88e2ca308094 ("mld: convert ifmcaddr6 to RCU") these external locks were
removed, so we probably need to restore the original rcu-safe call.

Otherwise, we occasionally get a machine crashed/stalled with the following
in dmesg:

[ 3405.966610][T230589] general protection fault, probably for non-canonical address 0xdead00000000008c: 0000 [#1] SMP NOPTI
[ 3405.982083][T230589] CPU: 44 PID: 230589 Comm: kworker/44:3 Tainted: G           O      5.15.19-cloudflare-2022.2.1 #1
[ 3405.998061][T230589] Hardware name: SUPA-COOL-SERV
[ 3406.009552][T230589] Workqueue: mld mld_ifc_work
[ 3406.017224][T230589] RIP: 0010:__ipv6_get_lladdr+0x34/0x60
[ 3406.025780][T230589] Code: 57 10 48 83 c7 08 48 89 e5 48 39 d7 74 3e 48 8d 82 38 ff ff ff eb 13 48 8b 90 d0 00 00 00 48 8d 82 38 ff ff ff 48 39 d7 74 22 <66> 83 78 32 20 77 1b 75 e4 89 ca 23 50 2c 75 dd 48 8b 50 08 48 8b
[ 3406.055748][T230589] RSP: 0018:ffff94e4b3fc3d10 EFLAGS: 00010202
[ 3406.065617][T230589] RAX: dead00000000005a RBX: ffff94e4b3fc3d30 RCX: 0000000000000040
[ 3406.077477][T230589] RDX: dead000000000122 RSI: ffff94e4b3fc3d30 RDI: ffff8c3a31431008
[ 3406.089389][T230589] RBP: ffff94e4b3fc3d10 R08: 0000000000000000 R09: 0000000000000000
[ 3406.101445][T230589] R10: ffff8c3a31430000 R11: 000000000000000b R12: ffff8c2c37887100
[ 3406.113553][T230589] R13: ffff8c3a39537000 R14: 00000000000005dc R15: ffff8c3a31431000
[ 3406.125730][T230589] FS:  0000000000000000(0000) GS:ffff8c3b9fc80000(0000) knlGS:0000000000000000
[ 3406.138992][T230589] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3406.149895][T230589] CR2: 00007f0dfea1db60 CR3: 000000387b5f2000 CR4: 0000000000350ee0
[ 3406.162421][T230589] Call Trace:
[ 3406.170235][T230589]  
[ 3406.177736][T230589]  mld_newpack+0xfe/0x1a0
[ 3406.186686][T230589]  add_grhead+0x87/0xa0
[ 3406.195498][T230589]  add_grec+0x485/0x4e0
[ 3406.204310][T230589]  ? newidle_balance+0x126/0x3f0
[ 3406.214024][T230589]  mld_ifc_work+0x15d/0x450
[ 3406.223279][T230589]  process_one_work+0x1e6/0x380
[ 3406.232982][T230589]  worker_thread+0x50/0x3a0
[ 3406.242371][T230589]  ? rescuer_thread+0x360/0x360
[ 3406.252175][T230589]  kthread+0x127/0x150
[ 3406.261197][T230589]  ? set_kthread_struct+0x40/0x40
[ 3406.271287][T230589]  ret_from_fork+0x22/0x30
[ 3406.280812][T230589]  
[ 3406.288937][T230589] Modules linked in: ... [last unloaded: kheaders]
[ 3406.476714][T230589] ---[ end trace 3525a7655f2f3b9e ]---

Fixes: 88e2ca308094 ("mld: convert ifmcaddr6 to RCU")
Reported-by: David Pinilla Caparros 
Signed-off-by: Ignat Korchagin 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: L2CAP: Fix regressions caused by reusing ident

2026-07-24T13:49:23+00:00

commit 761fb8ec8778f0caf2bba5a41e3cff1ea86974f3 upstream.

This attempt to fix regressions caused by reusing ident which apparently
is not handled well on certain stacks causing the stack to not respond to
requests, so instead of simple returning the first unallocated id this
stores the last used tx_ident and then attempt to use the next until all
available ids are exausted and then cycle starting over to 1.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=221120
Link: https://bugzilla.kernel.org/show_bug.cgi?id=221177
Fixes: 6c3ea155e5ee ("Bluetooth: L2CAP: Fix not tracking outstanding TX ident")
Signed-off-by: Luiz Augusto von Dentz 
Tested-by: Christian Eggers 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: L2CAP: Fix not tracking outstanding TX ident

2026-07-24T13:49:20+00:00

[ Upstream commit 6c3ea155e5ee3e56606233acde8309afda66d483 ]

This attempts to proper track outstanding request by using struct ida
and allocating from it in l2cap_get_ident using ida_alloc_range which
would reuse ids as they are free, then upon completion release
the id using ida_free.

This fixes the qualification test case L2CAP/COS/CED/BI-29-C which
attempts to check if the host stack is able to work after 256 attempts
to connect which requires Ident field to use the full range of possible
values in order to pass the test.

Link: https://github.com/bluez/bluez/issues/1829
Signed-off-by: Luiz Augusto von Dentz 
Reviewed-by: Paul Menzel 
Stable-dep-of: 2641a9e0a1dd ("Bluetooth: L2CAP: cancel pending_rx_work before taking conn->lock")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ipvs: pass parsed transport offset to state handlers

2026-07-24T13:49:08+00:00

[ Upstream commit bae7ce7bafb59e42dc0e0e2999fdd9d1cffe3866 ]

IPVS callers already parse the packet into struct ip_vs_iphdr before
updating connection state. For IPv6 this records the real
transport-header offset after extension headers in iph.len.

Pass this parsed transport offset through ip_vs_set_state() and the
protocol state_transition() callback so protocol handlers can use the
same packet context as scheduling and NAT handling. This patch only
changes the common callback plumbing and adapts the protocol callback
signatures; TCP and SCTP start using the value in follow-up patches.

Signed-off-by: Yizhou Zhao 
Acked-by: Julian Anastasov 
Signed-off-by: Florian Westphal 
Stable-dep-of: 2500fa3958b1 ("ipvs: use parsed transport offset in TCP state lookup")
Signed-off-by: Sasha Levin

ipv6: mcast: Fix potential UAF in MLD delayed work

2026-07-24T13:49:08+00:00

[ Upstream commit 9b26518b6896a16b809b1e42986f4ebac7bccc1e ]

A race condition exists between device teardown and incoming MLD query
processing, leading to a Use-After-Free in the MLD delayed work.

During device destruction, the primary reference to inet6_dev is dropped,
which can drop its refcount to 0. The actual freeing of inet6_dev memory
is deferred via RCU.

Concurrently, the packet receive path runs under RCU read lock and obtains
the inet6_dev pointer. Because the memory is RCU-protected, CPU-0 can
safely dereference inet6_dev even if its refcount has hit 0.

However, if CPU-0 calls igmp6_event_query() and schedules delayed work, it
attempts to acquire a reference using in6_dev_hold(). This increments the
refcount from 0 to 1, triggering a "refcount_t: addition on 0" warning.
Since the inet6_dev memory is still scheduled to be freed after the RCU
grace period, the device is freed while the work is still scheduled.
When the work runs, it accesses the freed memory, causing a kernel panic.

Fix this by using refcount_inc_not_zero() (via a new helper
in6_dev_hold_safe()) to prevent acquiring a reference if the device is
already being destroyed. If the refcount is 0, we do not schedule the work.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet 
Reviewed-by: Ido Schimmel 
Link: https://patch.msgid.link/20260705181756.963063-3-edumazet@google.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

ipv6: fix skb drops in igmp6_event_query() and igmp6_event_report()

2026-07-24T13:49:07+00:00

[ Upstream commit 2d3916f3189172d5c69d33065c3c21119fe539fc ]

While investigating on why a synchronize_net() has been added recently
in ipv6_mc_down(), I found that igmp6_event_query() and igmp6_event_report()
might drop skbs in some cases.

Discussion about removing synchronize_net() from ipv6_mc_down()
will happen in a different thread.

Fixes: f185de28d9ae ("mld: add new workqueues for process mld events")
Signed-off-by: Eric Dumazet 
Cc: Taehee Yoo 
Cc: Cong Wang 
Cc: David Ahern 
Link: https://lore.kernel.org/r/20220303173728.937869-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski 
Stable-dep-of: 9b26518b6896 ("ipv6: mcast: Fix potential UAF in MLD delayed work")
Signed-off-by: Sasha Levin

mld: add mc_lock for protecting per-interface mld data

2026-07-24T13:49:07+00:00

[ Upstream commit 63ed8de4be81b699ca727e9f8e3344bd487806d7 ]

The purpose of this lock is to avoid a bottleneck in the query/report
event handler logic.

By previous patches, almost all mld data is protected by RTNL.
So, the query and report event handler, which is data path logic
acquires RTNL too. Therefore if a lot of query and report events
are received, it uses RTNL for a long time.
So it makes the control-plane bottleneck because of using RTNL.
In order to avoid this bottleneck, mc_lock is added.

mc_lock protect only per-interface mld data and per-interface mld
data is used in the query/report event handler logic.
So, no longer rtnl_lock is needed in the query/report event handler logic.
Therefore bottleneck will be disappeared by mc_lock.

Suggested-by: Cong Wang 
Signed-off-by: Taehee Yoo 
Signed-off-by: David S. Miller 
Stable-dep-of: 9b26518b6896 ("ipv6: mcast: Fix potential UAF in MLD delayed work")
Signed-off-by: Sasha Levin

mld: add new workqueues for process mld events

2026-07-24T13:49:07+00:00

[ Upstream commit f185de28d9ae6c978135993769352e523ee8df06 ]

When query/report packets are received, mld module processes them.
But they are processed under BH context so it couldn't use sleepable
functions. So, in order to switch context, the two workqueues are
added which processes query and report event.

In the struct inet6_dev, mc_{query | report}_queue are added so it
is per-interface queue.
And mc_{query | report}_work are workqueue structure.

When the query or report event is received, skb is queued to proper
queue and worker function is scheduled immediately.
Workqueues and queues are protected by spinlock, which is
mc_{query | report}_lock, and worker functions are protected by RTNL.

Suggested-by: Cong Wang 
Signed-off-by: Taehee Yoo 
Signed-off-by: David S. Miller 
Stable-dep-of: 9b26518b6896 ("ipv6: mcast: Fix potential UAF in MLD delayed work")
Signed-off-by: Sasha Levin

mld: convert ifmcaddr6 to RCU

2026-07-24T13:49:07+00:00

[ Upstream commit 88e2ca3080947fe22eb520c1f8231e79a105d011 ]

The ifmcaddr6 has been protected by inet6_dev->lock(rwlock) so that
the critical section is atomic context. In order to switch this context,
changing locking is needed. The ifmcaddr6 actually already protected by
RTNL So if it's converted to use RCU, its control path context can be
switched to sleepable.

Suggested-by: Cong Wang 
Signed-off-by: Taehee Yoo 
Signed-off-by: David S. Miller 
Stable-dep-of: 9b26518b6896 ("ipv6: mcast: Fix potential UAF in MLD delayed work")
Signed-off-by: Sasha Levin

mld: convert ip6_sf_list to RCU

2026-07-24T13:49:07+00:00

[ Upstream commit 4b200e398953c237c86d32bf26d4cb2a96556a6f ]

The ip6_sf_list has been protected by mca_lock(spin_lock) so that the
critical section is atomic context. In order to switch this context,
changing locking is needed. The ip6_sf_list actually already protected
by RTNL So if it's converted to use RCU, its control path context can
be switched to sleepable.
But It doesn't remove mca_lock yet because ifmcaddr6 isn't converted
to RCU yet. So, It's not fully converted to the sleepable context.

Suggested-by: Cong Wang 
Signed-off-by: Taehee Yoo 
Signed-off-by: David S. Miller 
Stable-dep-of: 9b26518b6896 ("ipv6: mcast: Fix potential UAF in MLD delayed work")
Signed-off-by: Sasha Levin