<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git, branch v5.10.261</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v5.10.261</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v5.10.261'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2026-07-24T13:49:24+00:00</updated>
<entry>
<title>Linux 5.10.261</title>
<updated>2026-07-24T13:49:24+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2026-07-24T13:49:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8ba4813938919857c129400fae2d80fcebb69b8f'/>
<id>urn:sha1:8ba4813938919857c129400fae2d80fcebb69b8f</id>
<content type='text'>
Link: https://lore.kernel.org/r/20260721152355.667394603@linuxfoundation.org
Tested-by: Woody Suwalski &lt;terraluna977@gmail.com&gt;
Tested-by: Brett A C Sheffield &lt;bacs@librecast.net&gt;
Tested-by: Dominique Martinet &lt;dominique.martinet@atmark-techno.com&gt;
Link: https://lore.kernel.org/r/20260722142749.280611149@linuxfoundation.org
Tested-by: Brett A C Sheffield &lt;bacs@librecast.net&gt;
Tested-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Tested-by: Pavel Machek (CIP) &lt;pavel@nabladev.com&gt;
Tested-by: Mark Brown &lt;broonie@kernel.org&gt;
Tested-by: Barry K. Nathan &lt;barryn@pobox.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>tools/resolve_btfids: Emit warnings and patch zero id for missing symbols</title>
<updated>2026-07-24T13:49:24+00:00</updated>
<author>
<name>Hengqi Chen</name>
<email>hengqi.chen@gmail.com</email>
</author>
<published>2021-07-27T13:25:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=791f3a533aab39e2eb95528c5e5e66450f75ef0c'/>
<id>urn:sha1:791f3a533aab39e2eb95528c5e5e66450f75ef0c</id>
<content type='text'>
commit 5aad03685185b5133a28e1ee1d4e98d3fd3642a3 upstream.

Kernel functions referenced by .BTF_ids may be changed from global to static
and get inlined or get renamed/removed, and thus disappears from BTF.
This causes kernel build failure when resolve_btfids do id patch for symbols
in .BTF_ids in vmlinux. Update resolve_btfids to emit warning messages and
patch zero id for missing symbols instead of aborting kernel build process.

Suggested-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Hengqi Chen &lt;hengqi.chen@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Yonghong Song &lt;yhs@fb.com&gt;
Link: https://lore.kernel.org/bpf/20210727132532.2473636-2-hengqi.chen@gmail.com
Cc: "Barry K. Nathan" &lt;barryn@pobox.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>tools/resolve_btfids: Fix some error messages</title>
<updated>2026-07-24T13:49:24+00:00</updated>
<author>
<name>Brendan Jackman</name>
<email>jackmanb@google.com</email>
</author>
<published>2020-12-03T10:22:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=0a9bd606628c63233e673e1a1e53e5ee224a2387'/>
<id>urn:sha1:0a9bd606628c63233e673e1a1e53e5ee224a2387</id>
<content type='text'>
commit 22e8ebe35a2e30ee19e02c41cacc99c2f896bc4b upstream.

Add missing newlines and fix polarity of strerror argument.

Signed-off-by: Brendan Jackman &lt;jackmanb@google.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Link: https://lore.kernel.org/bpf/20201203102234.648540-1-jackmanb@google.com
Cc: "Barry K. Nathan" &lt;barryn@pobox.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>perf/x86/amd/core: Always use the NMI latency mitigation</title>
<updated>2026-07-24T13:49:24+00:00</updated>
<author>
<name>Sandipan Das</name>
<email>sandipan.das@amd.com</email>
</author>
<published>2026-06-01T14:58:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=252bc0450f3b25bdf328975e5f11a1865951b241'/>
<id>urn:sha1:252bc0450f3b25bdf328975e5f11a1865951b241</id>
<content type='text'>
commit 73a4c02f94a98d94480c3e5c81450215a4da05ba upstream.

Commit df4d29732fda ("perf/x86/amd: Change/fix NMI latency mitigation
to use a timestamp") fixed handling of late-arriving NMIs but limited
the mitigation to processors having X86_FEATURE_PERFCTR_CORE. However,
it is unclear if processors without this feature are also affected.
When Mediated vPMU is enabled on affected hardware, it is also possible
to bypass the fix inside KVM guests if X86_FEATURE_PERFCTR_CORE is
removed from the guest CPUID (e.g. using "-cpu host,-perfctr-core" with
QEMU). Hence, use the mitigation at all times.

Fixes: df4d29732fda ("perf/x86/amd: Change/fix NMI latency mitigation to use a timestamp")
Signed-off-by: Sandipan Das &lt;sandipan.das@amd.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://patch.msgid.link/29a3c970da289ab8f24282933bdb36545c0403e8.1780325517.git.sandipan.das@amd.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>mld: fix suspicious RCU usage in __ipv6_dev_mc_dec()</title>
<updated>2026-07-24T13:49:24+00:00</updated>
<author>
<name>Taehee Yoo</name>
<email>ap420073@gmail.com</email>
</author>
<published>2021-04-16T14:16:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=b58363bf680a389501a20a551038d47b464f819b'/>
<id>urn:sha1:b58363bf680a389501a20a551038d47b464f819b</id>
<content type='text'>
commit aa8caa767e319bad34a82bfce7da1ed2b9c0ed6f upstream.

__ipv6_dev_mc_dec() internally uses sleepable functions so that caller
must not acquire atomic locks. But caller, which is addrconf_verify_rtnl()
acquires rcu_read_lock_bh().
So this warning occurs in the __ipv6_dev_mc_dec().

Test commands:
    ip netns add A
    ip link add veth0 type veth peer name veth1
    ip link set veth1 netns A
    ip link set veth0 up
    ip netns exec A ip link set veth1 up
    ip a a 2001:db8::1/64 dev veth0 valid_lft 2 preferred_lft 1

Splat looks like:
============================
WARNING: suspicious RCU usage
5.12.0-rc6+ #515 Not tainted
-----------------------------
kernel/sched/core.c:8294 Illegal context switch in RCU-bh read-side
critical section!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
4 locks held by kworker/4:0/1997:
 #0: ffff88810bd72d48 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at:
process_one_work+0x761/0x1440
 #1: ffff888105c8fe00 ((addr_chk_work).work){+.+.}-{0:0}, at:
process_one_work+0x795/0x1440
 #2: ffffffffb9279fb0 (rtnl_mutex){+.+.}-{3:3}, at:
addrconf_verify_work+0xa/0x20
 #3: ffffffffb8e30860 (rcu_read_lock_bh){....}-{1:2}, at:
addrconf_verify_rtnl+0x23/0xc60

stack backtrace:
CPU: 4 PID: 1997 Comm: kworker/4:0 Not tainted 5.12.0-rc6+ #515
Workqueue: ipv6_addrconf addrconf_verify_work
Call Trace:
 dump_stack+0xa4/0xe5
 ___might_sleep+0x27d/0x2b0
 __mutex_lock+0xc8/0x13f0
 ? lock_downgrade+0x690/0x690
 ? __ipv6_dev_mc_dec+0x49/0x2a0
 ? mark_held_locks+0xb7/0x120
 ? mutex_lock_io_nested+0x1270/0x1270
 ? lockdep_hardirqs_on_prepare+0x12c/0x3e0
 ? _raw_spin_unlock_irqrestore+0x47/0x50
 ? trace_hardirqs_on+0x41/0x120
 ? __wake_up_common_lock+0xc9/0x100
 ? __wake_up_common+0x620/0x620
 ? memset+0x1f/0x40
 ? netlink_broadcast_filtered+0x2c4/0xa70
 ? __ipv6_dev_mc_dec+0x49/0x2a0
 __ipv6_dev_mc_dec+0x49/0x2a0
 ? netlink_broadcast_filtered+0x2f6/0xa70
 addrconf_leave_solict.part.64+0xad/0xf0
 ? addrconf_join_solict.part.63+0xf0/0xf0
 ? nlmsg_notify+0x63/0x1b0
 __ipv6_ifa_notify+0x22c/0x9c0
 ? inet6_fill_ifaddr+0xbe0/0xbe0
 ? lockdep_hardirqs_on_prepare+0x12c/0x3e0
 ? __local_bh_enable_ip+0xa5/0xf0
 ? ipv6_del_addr+0x347/0x870
 ipv6_del_addr+0x3b1/0x870
 ? addrconf_ifdown+0xfe0/0xfe0
 ? rcu_read_lock_any_held.part.27+0x20/0x20
 addrconf_verify_rtnl+0x8a9/0xc60
 addrconf_verify_work+0xf/0x20
 process_one_work+0x84c/0x1440

In order to avoid this problem, it uses rcu_read_unlock_bh() for
a short time. RCU is used for avoiding freeing
ifp(struct *inet6_ifaddr) while ifp is being used. But this will
not be released even if rcu_read_unlock_bh() is used.
Because before rcu_read_unlock_bh(), it uses in6_ifa_hold(ifp).
So this is safe.

Fixes: 63ed8de4be81 ("mld: add mc_lock for protecting per-interface mld data")
Suggested-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>ipv6: mcast: remove one synchronize_net() barrier in ipv6_mc_down()</title>
<updated>2026-07-24T13:49:24+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2024-02-09T15:30:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=bfd2f3c58ad86ad33db80515e6c3503e0414e44b'/>
<id>urn:sha1:bfd2f3c58ad86ad33db80515e6c3503e0414e44b</id>
<content type='text'>
commit 17ef8efc00b34918b966388b2af0993811895a8c upstream.

As discussed in the past (commit 2d3916f31891 ("ipv6: fix skb drops
in igmp6_event_query() and igmp6_event_report()")) I think the
synchronize_net() call in ipv6_mc_down() is not needed.

Under load, synchronize_net() can last between 200 usec and 5 ms.

KASAN seems to agree as well.

Fixes: f185de28d9ae ("mld: add new workqueues for process mld events")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Taehee Yoo &lt;ap420073@gmail.com&gt;
Cc: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Cc: David Ahern &lt;dsahern@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>ipv6: mcast: fix data-race in ipv6_mc_down / mld_ifc_work</title>
<updated>2026-07-24T13:49:24+00:00</updated>
<author>
<name>Nikita Zhandarovich</name>
<email>n.zhandarovich@fintech.ru</email>
</author>
<published>2024-01-17T17:21:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=75ddcd741d2a30696f5893bc71a9d28f4ef22311'/>
<id>urn:sha1:75ddcd741d2a30696f5893bc71a9d28f4ef22311</id>
<content type='text'>
commit 2e7ef287f07c74985f1bf2858bedc62bd9ebf155 upstream.

idev-&gt;mc_ifc_count can be written over without proper locking.

Originally found by syzbot [1], fix this issue by encapsulating calls
to mld_ifc_stop_work() (and mld_gq_stop_work() for good measure) with
mutex_lock() and mutex_unlock() accordingly as these functions
should only be called with mc_lock per their declarations.

[1]
BUG: KCSAN: data-race in ipv6_mc_down / mld_ifc_work

write to 0xffff88813a80c832 of 1 bytes by task 3771 on cpu 0:
 mld_ifc_stop_work net/ipv6/mcast.c:1080 [inline]
 ipv6_mc_down+0x10a/0x280 net/ipv6/mcast.c:2725
 addrconf_ifdown+0xe32/0xf10 net/ipv6/addrconf.c:3949
 addrconf_notify+0x310/0x980
 notifier_call_chain kernel/notifier.c:93 [inline]
 raw_notifier_call_chain+0x6b/0x1c0 kernel/notifier.c:461
 __dev_notify_flags+0x205/0x3d0
 dev_change_flags+0xab/0xd0 net/core/dev.c:8685
 do_setlink+0x9f6/0x2430 net/core/rtnetlink.c:2916
 rtnl_group_changelink net/core/rtnetlink.c:3458 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3717 [inline]
 rtnl_newlink+0xbb3/0x1670 net/core/rtnetlink.c:3754
 rtnetlink_rcv_msg+0x807/0x8c0 net/core/rtnetlink.c:6558
 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2545
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6576
 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
 netlink_unicast+0x589/0x650 net/netlink/af_netlink.c:1368
 netlink_sendmsg+0x66e/0x770 net/netlink/af_netlink.c:1910
 ...

write to 0xffff88813a80c832 of 1 bytes by task 22 on cpu 1:
 mld_ifc_work+0x54c/0x7b0 net/ipv6/mcast.c:2653
 process_one_work kernel/workqueue.c:2627 [inline]
 process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2700
 worker_thread+0x525/0x730 kernel/workqueue.c:2781
 ...

Fixes: 2d9a93b4902b ("mld: convert from timer to delayed work")
Reported-by: syzbot+a9400cabb1d784e49abf@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/000000000000994e09060ebcdffb@google.com/
Signed-off-by: Nikita Zhandarovich &lt;n.zhandarovich@fintech.ru&gt;
Acked-by: Taehee Yoo &lt;ap420073@gmail.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Hangbin Liu &lt;liuhangbin@gmail.com&gt;
Link: https://lore.kernel.org/r/20240117172102.12001-1-n.zhandarovich@fintech.ru
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>net: mld: fix reference count leak in mld_{query | report}_work()</title>
<updated>2026-07-24T13:49:24+00:00</updated>
<author>
<name>Taehee Yoo</name>
<email>ap420073@gmail.com</email>
</author>
<published>2022-07-22T17:06:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=f0759634e491fb30ca5aa60d71a15ca7c24ecd69'/>
<id>urn:sha1:f0759634e491fb30ca5aa60d71a15ca7c24ecd69</id>
<content type='text'>
commit 3e7d18b9dca388940a19cae30bfc1f76dccd8c28 upstream.

mld_{query | report}_work() processes queued events.
If there are too many events in the queue, it re-queue a work.
And then, it returns without in6_dev_put().
But if queuing is failed, it should call in6_dev_put(), but it doesn't.
So, a reference count leak would occur.

THREAD0				THREAD1
mld_report_work()
				spin_lock_bh()
				if (!mod_delayed_work())
					in6_dev_hold();
				spin_unlock_bh()
	spin_lock_bh()
	schedule_delayed_work()
	spin_unlock_bh()

Script to reproduce(by Hangbin Liu):
   ip netns add ns1
   ip netns add ns2
   ip netns exec ns1 sysctl -w net.ipv6.conf.all.force_mld_version=1
   ip netns exec ns2 sysctl -w net.ipv6.conf.all.force_mld_version=1

   ip -n ns1 link add veth0 type veth peer name veth0 netns ns2
   ip -n ns1 link set veth0 up
   ip -n ns2 link set veth0 up

   for i in `seq 50`; do
           for j in `seq 100`; do
                   ip -n ns1 addr add 2021:${i}::${j}/64 dev veth0
                   ip -n ns2 addr add 2022:${i}::${j}/64 dev veth0
           done
   done
   modprobe -r veth
   ip -a netns del

splat looks like:
 unregister_netdevice: waiting for veth0 to become free. Usage count = 2
 leaked reference.
  ipv6_add_dev+0x324/0xec0
  addrconf_notify+0x481/0xd10
  raw_notifier_call_chain+0xe3/0x120
  call_netdevice_notifiers+0x106/0x160
  register_netdevice+0x114c/0x16b0
  veth_newlink+0x48b/0xa50 [veth]
  rtnl_newlink+0x11a2/0x1a40
  rtnetlink_rcv_msg+0x63f/0xc00
  netlink_rcv_skb+0x1df/0x3e0
  netlink_unicast+0x5de/0x850
  netlink_sendmsg+0x6c9/0xa90
  ____sys_sendmsg+0x76a/0x780
  __sys_sendmsg+0x27c/0x340
  do_syscall_64+0x43/0x90
  entry_SYSCALL_64_after_hwframe+0x63/0xcd

Tested-by: Hangbin Liu &lt;liuhangbin@gmail.com&gt;
Fixes: f185de28d9ae ("mld: add new workqueues for process mld events")
Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>ipv6: fix lockdep splat in in6_dump_addrs()</title>
<updated>2026-07-24T13:49:24+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2022-06-28T12:12:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=ea18594da69a09f68491da57f9fa09f003efbbc7'/>
<id>urn:sha1:ea18594da69a09f68491da57f9fa09f003efbbc7</id>
<content type='text'>
commit 4e43e64d0f1332fcc503babad4dc31aead7131ca upstream.

As reported by syzbot, we should not use rcu_dereference()
when rcu_read_lock() is not held.

WARNING: suspicious RCU usage
5.19.0-rc2-syzkaller #0 Not tainted

net/ipv6/addrconf.c:5175 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor326/3617:
 #0: ffffffff8d5848e8 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0xae/0xc20 net/netlink/af_netlink.c:2223

stack backtrace:
CPU: 0 PID: 3617 Comm: syz-executor326 Not tainted 5.19.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 &lt;TASK&gt;
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 in6_dump_addrs+0x12d1/0x1790 net/ipv6/addrconf.c:5175
 inet6_dump_addr+0x9c1/0xb50 net/ipv6/addrconf.c:5300
 netlink_dump+0x541/0xc20 net/netlink/af_netlink.c:2275
 __netlink_dump_start+0x647/0x900 net/netlink/af_netlink.c:2380
 netlink_dump_start include/linux/netlink.h:245 [inline]
 rtnetlink_rcv_msg+0x73e/0xc90 net/core/rtnetlink.c:6046
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2492
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2546
 __sys_sendmsg net/socket.c:2575 [inline]
 __do_sys_sendmsg net/socket.c:2584 [inline]
 __se_sys_sendmsg net/socket.c:2582 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2582
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Fixes: 88e2ca308094 ("mld: convert ifmcaddr6 to RCU")
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Taehee Yoo &lt;ap420073@gmail.com&gt;
Link: https://lore.kernel.org/r/20220628121248.858695-1-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>ipv6: mcast: use rcu-safe version of ipv6_get_lladdr()</title>
<updated>2026-07-24T13:49:23+00:00</updated>
<author>
<name>Ignat Korchagin</name>
<email>ignat@cloudflare.com</email>
</author>
<published>2022-02-11T17:30:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c49c69dc9f3e699fa3150aca7b189eea707b4047'/>
<id>urn:sha1:c49c69dc9f3e699fa3150aca7b189eea707b4047</id>
<content type='text'>
commit 26394fc118d6115390bd5b3a0fb17096271da227 upstream.

Some time ago 8965779d2c0e ("ipv6,mcast: always hold idev-&gt;lock before mca_lock")
switched ipv6_get_lladdr() to __ipv6_get_lladdr(), which is rcu-unsafe
version. That was OK, because idev-&gt;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 &lt;66&gt; 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]  &lt;TASK&gt;
[ 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]  &lt;/TASK&gt;
[ 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 &lt;dpini@cloudflare.com&gt;
Signed-off-by: Ignat Korchagin &lt;ignat@cloudflare.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
