<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/ipv4, branch v6.6.146</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>net: ipip: require CAP_NET_ADMIN in the device netns for changelink</title>
<updated>2026-07-24T14:03:42+00:00</updated>
<author>
<name>Maoyi Xie</name>
<email>maoyixie.tju@gmail.com</email>
</author>
<published>2026-06-12T08:59:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=983cc4aa7e6f633b34c3ee743771252d7afa9a90'/>
<id>983cc4aa7e6f633b34c3ee743771252d7afa9a90</id>
<content type='text'>
commit 8211a26324667980a463c069469a818e71207e02 upstream.

ipip_changelink() operates on at most two netns, dev_net(dev) and the
tunnel link netns t-&gt;net. They differ once the device is created in or
moved to a netns other than the one the request runs in. The rtnl
changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a
caller privileged there but not in t-&gt;net can rewrite a tunnel that
lives in t-&gt;net.

Gate ipip_changelink() on rtnl_dev_link_net_capable() at its top,
before any attribute is parsed.

Reported-by: Xiao Liang &lt;shaw.leon@gmail.com&gt;
Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/
Fixes: 6c742e714d8c ("ipip: add x-netns support")
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie &lt;maoyixie.tju@gmail.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Link: https://patch.msgid.link/20260612085941.3158249-3-maoyixie.tju@gmail.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 8211a26324667980a463c069469a818e71207e02 upstream.

ipip_changelink() operates on at most two netns, dev_net(dev) and the
tunnel link netns t-&gt;net. They differ once the device is created in or
moved to a netns other than the one the request runs in. The rtnl
changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a
caller privileged there but not in t-&gt;net can rewrite a tunnel that
lives in t-&gt;net.

Gate ipip_changelink() on rtnl_dev_link_net_capable() at its top,
before any attribute is parsed.

Reported-by: Xiao Liang &lt;shaw.leon@gmail.com&gt;
Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/
Fixes: 6c742e714d8c ("ipip: add x-netns support")
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie &lt;maoyixie.tju@gmail.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Link: https://patch.msgid.link/20260612085941.3158249-3-maoyixie.tju@gmail.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: ip_vti: require CAP_NET_ADMIN in the device netns for changelink</title>
<updated>2026-07-24T14:03:42+00:00</updated>
<author>
<name>Maoyi Xie</name>
<email>maoyixie.tju@gmail.com</email>
</author>
<published>2026-06-12T08:59:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=33fd93961557ec8e3e9958995b28684c5f949394'/>
<id>33fd93961557ec8e3e9958995b28684c5f949394</id>
<content type='text'>
commit 95cceadbfd52d7239bd730afdda0655287d77425 upstream.

vti_changelink() operates on at most two netns, dev_net(dev) and the
tunnel link netns t-&gt;net. They differ once the device is created in or
moved to a netns other than the one the request runs in. The rtnl
changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a
caller privileged there but not in t-&gt;net can rewrite a tunnel that
lives in t-&gt;net.

Gate vti_changelink() on rtnl_dev_link_net_capable() at its top,
before any attribute is parsed.

Reported-by: Xiao Liang &lt;shaw.leon@gmail.com&gt;
Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/
Fixes: 895de9a3488a ("vti4: Enable namespace changing")
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie &lt;maoyixie.tju@gmail.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Link: https://patch.msgid.link/20260612085941.3158249-4-maoyixie.tju@gmail.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 95cceadbfd52d7239bd730afdda0655287d77425 upstream.

vti_changelink() operates on at most two netns, dev_net(dev) and the
tunnel link netns t-&gt;net. They differ once the device is created in or
moved to a netns other than the one the request runs in. The rtnl
changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a
caller privileged there but not in t-&gt;net can rewrite a tunnel that
lives in t-&gt;net.

Gate vti_changelink() on rtnl_dev_link_net_capable() at its top,
before any attribute is parsed.

Reported-by: Xiao Liang &lt;shaw.leon@gmail.com&gt;
Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/
Fixes: 895de9a3488a ("vti4: Enable namespace changing")
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie &lt;maoyixie.tju@gmail.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Link: https://patch.msgid.link/20260612085941.3158249-4-maoyixie.tju@gmail.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>ipv4: igmp: Fix potential UAF in igmp_gq_start_timer()</title>
<updated>2026-07-24T14:03:28+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2026-07-05T18:17:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=40a1e998cb266ed4cb529a0bb4fee2b0ba732702'/>
<id>40a1e998cb266ed4cb529a0bb4fee2b0ba732702</id>
<content type='text'>
[ Upstream commit 7b19c0f81ed1fdaec6bc522569be367199a9edf3 ]

A race condition exists between device teardown (inetdev_destroy) and
incoming IGMP query processing (igmp_rcv), leading to a Use-After-Free
in the IGMP timer callback.

During device destruction, inetdev_destroy() drops the primary reference
to in_device, which can drop its refcount to 0. The actual freeing of
in_device memory is deferred via RCU (using call_rcu()).

Concurrently, igmp_rcv() runs under RCU read lock and obtains the
in_device pointer. Because the memory is RCU-protected, CPU-0 can safely
dereference in_device even if its refcount has hit 0.

However, if CPU-0 calls igmp_gq_start_timer() and re-arms the timer, it
attempts to acquire a reference using in_dev_hold(). This increments the
refcount from 0 to 1, triggering a "refcount_t: addition on 0" warning.
Since the in_device memory is still scheduled to be freed after the RCU
grace period (as the free callback does not check the refcount again),
the device is freed while the timer is still armed. When the timer
expires, it accesses the freed memory, causing a kernel panic.

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

A similar issue in IPv6 MLD is fixed in a subsequent patch.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Zero Day Initiative &lt;zdi-disclosures@trendmicro.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Link: https://patch.msgid.link/20260705181756.963063-2-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 7b19c0f81ed1fdaec6bc522569be367199a9edf3 ]

A race condition exists between device teardown (inetdev_destroy) and
incoming IGMP query processing (igmp_rcv), leading to a Use-After-Free
in the IGMP timer callback.

During device destruction, inetdev_destroy() drops the primary reference
to in_device, which can drop its refcount to 0. The actual freeing of
in_device memory is deferred via RCU (using call_rcu()).

Concurrently, igmp_rcv() runs under RCU read lock and obtains the
in_device pointer. Because the memory is RCU-protected, CPU-0 can safely
dereference in_device even if its refcount has hit 0.

However, if CPU-0 calls igmp_gq_start_timer() and re-arms the timer, it
attempts to acquire a reference using in_dev_hold(). This increments the
refcount from 0 to 1, triggering a "refcount_t: addition on 0" warning.
Since the in_device memory is still scheduled to be freed after the RCU
grace period (as the free callback does not check the refcount again),
the device is freed while the timer is still armed. When the timer
expires, it accesses the freed memory, causing a kernel panic.

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

A similar issue in IPv6 MLD is fixed in a subsequent patch.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Zero Day Initiative &lt;zdi-disclosures@trendmicro.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Link: https://patch.msgid.link/20260705181756.963063-2-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>netfilter: nf_reject: skip iphdr options when looking for icmp header</title>
<updated>2026-07-24T14:03:20+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2026-06-18T08:49:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=76d1bc5498c7214a4ac9cf67d184cbba236b6755'/>
<id>76d1bc5498c7214a4ac9cf67d184cbba236b6755</id>
<content type='text'>
[ Upstream commit af8d6ae09c0a5f8b8a0d5680203c74b3c1daa85b ]

Not a big deal but this hould have used the real ip header length and not the
base header size.  As-is, if there are options then
nf_skb_is_icmp_unreach() result will be random.

Fixes: db99b2f2b3e2 ("netfilter: nf_reject: don't reply to icmp error messages")
Signed-off-by: Florian Westphal &lt;fw@strlen.de&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 af8d6ae09c0a5f8b8a0d5680203c74b3c1daa85b ]

Not a big deal but this hould have used the real ip header length and not the
base header size.  As-is, if there are options then
nf_skb_is_icmp_unreach() result will be random.

Fixes: db99b2f2b3e2 ("netfilter: nf_reject: don't reply to icmp error messages")
Signed-off-by: Florian Westphal &lt;fw@strlen.de&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>xfrm: Use the XFRM_GRO to indicate a GRO call on input</title>
<updated>2026-07-24T14:03:18+00:00</updated>
<author>
<name>Steffen Klassert</name>
<email>steffen.klassert@secunet.com</email>
</author>
<published>2023-10-04T13:05:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=22d554d9ba241337f8700cfe3916430d3383ff88'/>
<id>22d554d9ba241337f8700cfe3916430d3383ff88</id>
<content type='text'>
[ Upstream commit b439475a0dba2b50fb39a6356069969780e45fd4 ]

This is needed to support GRO for ESP in UDP encapsulation.

Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
Co-developed-by: Antony Antony &lt;antony.antony@secunet.com&gt;
Signed-off-by: Antony Antony &lt;antony.antony@secunet.com&gt;
Reviewed-by: Eyal Birger &lt;eyal.birger@gmail.com&gt;
Stable-dep-of: 68de007d5ac9 ("xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[]")
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 b439475a0dba2b50fb39a6356069969780e45fd4 ]

This is needed to support GRO for ESP in UDP encapsulation.

Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
Co-developed-by: Antony Antony &lt;antony.antony@secunet.com&gt;
Signed-off-by: Antony Antony &lt;antony.antony@secunet.com&gt;
Reviewed-by: Eyal Birger &lt;eyal.birger@gmail.com&gt;
Stable-dep-of: 68de007d5ac9 ("xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[]")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: ipv4: bound TCP reordering sysctl writes and MTU probe sizes</title>
<updated>2026-07-24T14:02:45+00:00</updated>
<author>
<name>Wyatt Feng</name>
<email>bronzed_45_vested@icloud.com</email>
</author>
<published>2026-06-15T10:31:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e81f805824a8109504fce090641b17d135b48cd1'/>
<id>e81f805824a8109504fce090641b17d135b48cd1</id>
<content type='text'>
commit efb8763d7bbb40cff4cc55a6b62c3095a038149c upstream.

Reject invalid `net.ipv4.tcp_reordering` values before they reach TCP
socket state. The sysctl is stored as an `int` but copied into the
`u32` `tp-&gt;reordering` field for new sockets, so negative writes wrap
to large values.

With `tcp_mtu_probing=2`, the wrapped value can overflow the
`tcp_mtu_probe()` size calculation and drive the MTU probing path into
an out-of-bounds read. Route `tcp_reordering` writes through
`proc_dointvec_minmax()` and require it to be at least 1. Also require
`tcp_max_reordering` to be at least 1 so the configured maximum cannot
become negative either.

When registering the table for a non-init network namespace, relocate
`extra2` pointers that refer into `init_net.ipv4` so the
`tcp_reordering` upper bound follows that namespace's
`tcp_max_reordering`.

Harden `tcp_mtu_probe()` itself by computing `size_needed` as `u64`.
This keeps the send queue and window checks from being bypassed through
signed integer overflow.

Fixes: 91cc17c0e5e5 ("[TCP]: MTUprobe: receiver window &amp; data available checks fixed")
Cc: stable@vger.kernel.org
Reported-by: Yuan Tan &lt;yuantan098@gmail.com&gt;
Reported-by: Zhengchuan Liang &lt;zcliangcn@gmail.com&gt;
Reported-by: Xin Liu &lt;bird@lzu.edu.cn&gt;
Suggested-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: Wyatt Feng &lt;bronzed_45_vested@icloud.com&gt;
Signed-off-by: Ren Wei &lt;n05ec@lzu.edu.cn&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://patch.msgid.link/1a5b7e1ef4d70fbad8c8ee0b82d8405f3c964a3d.1781395200.git.bronzed_45_vested@icloud.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 efb8763d7bbb40cff4cc55a6b62c3095a038149c upstream.

Reject invalid `net.ipv4.tcp_reordering` values before they reach TCP
socket state. The sysctl is stored as an `int` but copied into the
`u32` `tp-&gt;reordering` field for new sockets, so negative writes wrap
to large values.

With `tcp_mtu_probing=2`, the wrapped value can overflow the
`tcp_mtu_probe()` size calculation and drive the MTU probing path into
an out-of-bounds read. Route `tcp_reordering` writes through
`proc_dointvec_minmax()` and require it to be at least 1. Also require
`tcp_max_reordering` to be at least 1 so the configured maximum cannot
become negative either.

When registering the table for a non-init network namespace, relocate
`extra2` pointers that refer into `init_net.ipv4` so the
`tcp_reordering` upper bound follows that namespace's
`tcp_max_reordering`.

Harden `tcp_mtu_probe()` itself by computing `size_needed` as `u64`.
This keeps the send queue and window checks from being bypassed through
signed integer overflow.

Fixes: 91cc17c0e5e5 ("[TCP]: MTUprobe: receiver window &amp; data available checks fixed")
Cc: stable@vger.kernel.org
Reported-by: Yuan Tan &lt;yuantan098@gmail.com&gt;
Reported-by: Zhengchuan Liang &lt;zcliangcn@gmail.com&gt;
Reported-by: Xin Liu &lt;bird@lzu.edu.cn&gt;
Suggested-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: Wyatt Feng &lt;bronzed_45_vested@icloud.com&gt;
Signed-off-by: Ren Wei &lt;n05ec@lzu.edu.cn&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://patch.msgid.link/1a5b7e1ef4d70fbad8c8ee0b82d8405f3c964a3d.1781395200.git.bronzed_45_vested@icloud.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>ipv4: igmp: remove multicast group from hash table on device destruction</title>
<updated>2026-07-24T14:02:45+00:00</updated>
<author>
<name>Yuyang Huang</name>
<email>yuyanghuang@google.com</email>
</author>
<published>2026-07-01T23:50:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=76d030ac95e17f91d69a595f17ebc5979700cf9a'/>
<id>76d030ac95e17f91d69a595f17ebc5979700cf9a</id>
<content type='text'>
commit 7993211bde166471dffac074dc965489f86531f8 upstream.

When a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through
the multicast list and calls ip_ma_put() on each membership, scheduling
them for RCU reclamation. However, they are not unlinked from the device's
multicast hash table (mc_hash).

Since the device remains published in dev-&gt;ip_ptr until after
ip_mc_destroy_dev() completes, concurrent RCU readers traversing mc_hash
can still locate and access the multicast group after its refcount is
decremented. If the RCU callback runs and frees the group while a reader is
accessing it, a use-after-free occurs.

Fix this by unlinking the multicast group from mc_hash using
ip_mc_hash_remove() before scheduling it for reclamation.

BUG: KASAN: slab-use-after-free in ip_check_mc_rcu+0x149/0x3f0
Read of size 4 at addr ffff888009bf1408 by task mausezahn/2276

Call Trace:
 &lt;IRQ&gt;
 dump_stack_lvl+0x67/0x90
 print_report+0x175/0x7c0
 kasan_report+0x147/0x180
 ip_check_mc_rcu+0x149/0x3f0
 udp_v4_early_demux+0x36d/0x12d0
 ip_rcv_finish_core+0xb8b/0x1390
 ip_rcv_finish+0x54/0x120
 NF_HOOK+0x213/0x2b0
 __netif_receive_skb+0x126/0x340
 process_backlog+0x4f2/0xf00
 __napi_poll+0x92/0x2c0
 net_rx_action+0x583/0xc60
 handle_softirqs+0x236/0x7f0
 do_softirq+0x57/0x80
 &lt;/IRQ&gt;

Allocated by task 2239:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x72/0x90
 ____ip_mc_inc_group+0x31a/0xa40
 __ip_mc_join_group+0x334/0x3f0
 do_ip_setsockopt+0x16fa/0x2010
 ip_setsockopt+0x3f/0x90
 do_sock_setsockopt+0x1ad/0x300

Freed by task 0:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x40/0x50
 __kasan_slab_free+0x3a/0x60
 __rcu_free_sheaf_prepare+0xd4/0x220
 rcu_free_sheaf+0x36/0x190
 rcu_core+0x8d9/0x12f0
 handle_softirqs+0x236/0x7f0

Fixes: e9897071350b ("igmp: hash a hash table to speedup ip_check_mc_rcu()")
Cc: stable@vger.kernel.org
Signed-off-by: Yuyang Huang &lt;yuyanghuang@google.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Link: https://patch.msgid.link/20260701235014.73505-1-yuyanghuang@google.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&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 7993211bde166471dffac074dc965489f86531f8 upstream.

When a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through
the multicast list and calls ip_ma_put() on each membership, scheduling
them for RCU reclamation. However, they are not unlinked from the device's
multicast hash table (mc_hash).

Since the device remains published in dev-&gt;ip_ptr until after
ip_mc_destroy_dev() completes, concurrent RCU readers traversing mc_hash
can still locate and access the multicast group after its refcount is
decremented. If the RCU callback runs and frees the group while a reader is
accessing it, a use-after-free occurs.

Fix this by unlinking the multicast group from mc_hash using
ip_mc_hash_remove() before scheduling it for reclamation.

BUG: KASAN: slab-use-after-free in ip_check_mc_rcu+0x149/0x3f0
Read of size 4 at addr ffff888009bf1408 by task mausezahn/2276

Call Trace:
 &lt;IRQ&gt;
 dump_stack_lvl+0x67/0x90
 print_report+0x175/0x7c0
 kasan_report+0x147/0x180
 ip_check_mc_rcu+0x149/0x3f0
 udp_v4_early_demux+0x36d/0x12d0
 ip_rcv_finish_core+0xb8b/0x1390
 ip_rcv_finish+0x54/0x120
 NF_HOOK+0x213/0x2b0
 __netif_receive_skb+0x126/0x340
 process_backlog+0x4f2/0xf00
 __napi_poll+0x92/0x2c0
 net_rx_action+0x583/0xc60
 handle_softirqs+0x236/0x7f0
 do_softirq+0x57/0x80
 &lt;/IRQ&gt;

Allocated by task 2239:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x72/0x90
 ____ip_mc_inc_group+0x31a/0xa40
 __ip_mc_join_group+0x334/0x3f0
 do_ip_setsockopt+0x16fa/0x2010
 ip_setsockopt+0x3f/0x90
 do_sock_setsockopt+0x1ad/0x300

Freed by task 0:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x40/0x50
 __kasan_slab_free+0x3a/0x60
 __rcu_free_sheaf_prepare+0xd4/0x220
 rcu_free_sheaf+0x36/0x190
 rcu_core+0x8d9/0x12f0
 handle_softirqs+0x236/0x7f0

Fixes: e9897071350b ("igmp: hash a hash table to speedup ip_check_mc_rcu()")
Cc: stable@vger.kernel.org
Signed-off-by: Yuyang Huang &lt;yuyanghuang@google.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Link: https://patch.msgid.link/20260701235014.73505-1-yuyanghuang@google.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: prevent potential infinite loop in bond_header_parse()</title>
<updated>2026-07-24T14:02:38+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2026-07-08T09:47:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9532d0d0ad1d726c06f807e8f0f1ec93cbabb452'/>
<id>9532d0d0ad1d726c06f807e8f0f1ec93cbabb452</id>
<content type='text'>
[ Upstream commit b7405dcf7385445e10821777143f18c3ce20fa04 ]

bond_header_parse() can loop if a stack of two bonding devices is setup,
because skb-&gt;dev always points to the hierarchy top.

Add new "const struct net_device *dev" parameter to
(struct header_ops)-&gt;parse() method to make sure the recursion
is bounded, and that the final leaf parse method is called.

Fixes: 950803f72547 ("bonding: fix type confusion in bond_setup_by_slave()")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Jiayuan Chen &lt;jiayuan.chen@shopee.com&gt;
Tested-by: Jiayuan Chen &lt;jiayuan.chen@shopee.com&gt;
Cc: Jay Vosburgh &lt;jv@jvosburgh.net&gt;
Cc: Andrew Lunn &lt;andrew+netdev@lunn.ch&gt;
Link: https://patch.msgid.link/20260315104152.1436867-1-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
[backport to 6.6, also fix function for wireless/{cisco/hostap}]
Signed-off-by: Wentao Guan &lt;guanwentao@uniontech.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 b7405dcf7385445e10821777143f18c3ce20fa04 ]

bond_header_parse() can loop if a stack of two bonding devices is setup,
because skb-&gt;dev always points to the hierarchy top.

Add new "const struct net_device *dev" parameter to
(struct header_ops)-&gt;parse() method to make sure the recursion
is bounded, and that the final leaf parse method is called.

Fixes: 950803f72547 ("bonding: fix type confusion in bond_setup_by_slave()")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Jiayuan Chen &lt;jiayuan.chen@shopee.com&gt;
Tested-by: Jiayuan Chen &lt;jiayuan.chen@shopee.com&gt;
Cc: Jay Vosburgh &lt;jv@jvosburgh.net&gt;
Cc: Andrew Lunn &lt;andrew+netdev@lunn.ch&gt;
Link: https://patch.msgid.link/20260315104152.1436867-1-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
[backport to 6.6, also fix function for wireless/{cisco/hostap}]
Signed-off-by: Wentao Guan &lt;guanwentao@uniontech.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: ip_gre: require CAP_NET_ADMIN in the device netns for changelink</title>
<updated>2026-07-24T14:02:36+00:00</updated>
<author>
<name>Maoyi Xie</name>
<email>maoyixie.tju@gmail.com</email>
</author>
<published>2026-07-02T14:34:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e54c05ed3d9c28733fb9e5837219aca3691defa3'/>
<id>e54c05ed3d9c28733fb9e5837219aca3691defa3</id>
<content type='text'>
[ Upstream commit 8165f7ff57d9667d2bb477ef6af83ede7fed4ad7 ]

A tunnel changelink() operates on at most two netns, dev_net(dev) and
the tunnel link netns t-&gt;net. They differ once the device is created in
or moved to a netns other than the one the request runs in. The rtnl
changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a
caller privileged there but not in t-&gt;net can rewrite a tunnel that
lives in t-&gt;net.

Add rtnl_dev_link_net_capable() next to rtnl_get_net_ns_capable() in
net/core/rtnetlink.c. It requires CAP_NET_ADMIN in the link netns and is
skipped when the link netns is dev_net(dev), where the rtnl path already
checked it. The other patches in this series use the same helper.

Gate ipgre_changelink() and erspan_changelink() with it, at the top of
the op before any attribute is parsed, because the parsers update live
tunnel fields first. ipgre_netlink_parms() sets t-&gt;collect_md before
ip_tunnel_changelink() runs.

Commit 8b484efd5cb4 ("ip6: vti: Use ip6_tnl.net in
vti6_siocdevprivate().") added the same check on the ioctl path. This
adds it on RTM_NEWLINK.

Reported-by: Xiao Liang &lt;shaw.leon@gmail.com&gt;
Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/
Fixes: b57708add314 ("gre: add x-netns support")
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie &lt;maoyixie.tju@gmail.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Link: https://patch.msgid.link/20260612085941.3158249-2-maoyixie.tju@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@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>
[ Upstream commit 8165f7ff57d9667d2bb477ef6af83ede7fed4ad7 ]

A tunnel changelink() operates on at most two netns, dev_net(dev) and
the tunnel link netns t-&gt;net. They differ once the device is created in
or moved to a netns other than the one the request runs in. The rtnl
changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a
caller privileged there but not in t-&gt;net can rewrite a tunnel that
lives in t-&gt;net.

Add rtnl_dev_link_net_capable() next to rtnl_get_net_ns_capable() in
net/core/rtnetlink.c. It requires CAP_NET_ADMIN in the link netns and is
skipped when the link netns is dev_net(dev), where the rtnl path already
checked it. The other patches in this series use the same helper.

Gate ipgre_changelink() and erspan_changelink() with it, at the top of
the op before any attribute is parsed, because the parsers update live
tunnel fields first. ipgre_netlink_parms() sets t-&gt;collect_md before
ip_tunnel_changelink() runs.

Commit 8b484efd5cb4 ("ip6: vti: Use ip6_tnl.net in
vti6_siocdevprivate().") added the same check on the ioctl path. This
adds it on RTM_NEWLINK.

Reported-by: Xiao Liang &lt;shaw.leon@gmail.com&gt;
Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/
Fixes: b57708add314 ("gre: add x-netns support")
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie &lt;maoyixie.tju@gmail.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Link: https://patch.msgid.link/20260612085941.3158249-2-maoyixie.tju@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipv4: account for fraggap on the paged allocation path</title>
<updated>2026-07-04T11:42:25+00:00</updated>
<author>
<name>Wongi Lee</name>
<email>qw3rtyp0@gmail.com</email>
</author>
<published>2026-06-16T13:38:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ce494707a9c07f27c219ca67f3e138061f53d9b3'/>
<id>ce494707a9c07f27c219ca67f3e138061f53d9b3</id>
<content type='text'>
[ Upstream commit eca856950f7cb1a221e02b99d758409f2c5cec42 ]

In __ip_append_data(), when the paged-allocation branch is taken,
alloclen and pagedlen are computed as

	alloclen = fragheaderlen + transhdrlen;
	pagedlen = datalen - transhdrlen;

datalen already includes fraggap, but the fraggap bytes carried over
from the previous skb are copied into the new skb's linear area at
offset transhdrlen by the subsequent skb_copy_and_csum_bits(). The
linear area is therefore undersized by fraggap bytes while pagedlen is
overstated by the same amount.

The non-paged branch sets alloclen to fraglen, which already accounts
for fraggap because datalen does. Bring the paged branch in line by
adding fraggap to alloclen and subtracting it from pagedlen.

After this adjustment, copy no longer collapses to -fraggap on the
paged path, so remove the stale comment describing that old arithmetic.

Fixes: 8eb77cc73977 ("ipv4: avoid partial copy for zc")
Signed-off-by: Jungwoo Lee &lt;jwlee2217@gmail.com&gt;
Signed-off-by: Wongi Lee &lt;qw3rtyp0@gmail.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Link: https://patch.msgid.link/ajFR1eLAIs42TN3g@DESKTOP-19IMU7U.localdomain
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 eca856950f7cb1a221e02b99d758409f2c5cec42 ]

In __ip_append_data(), when the paged-allocation branch is taken,
alloclen and pagedlen are computed as

	alloclen = fragheaderlen + transhdrlen;
	pagedlen = datalen - transhdrlen;

datalen already includes fraggap, but the fraggap bytes carried over
from the previous skb are copied into the new skb's linear area at
offset transhdrlen by the subsequent skb_copy_and_csum_bits(). The
linear area is therefore undersized by fraggap bytes while pagedlen is
overstated by the same amount.

The non-paged branch sets alloclen to fraglen, which already accounts
for fraggap because datalen does. Bring the paged branch in line by
adding fraggap to alloclen and subtracting it from pagedlen.

After this adjustment, copy no longer collapses to -fraggap on the
paged path, so remove the stale comment describing that old arithmetic.

Fixes: 8eb77cc73977 ("ipv4: avoid partial copy for zc")
Signed-off-by: Jungwoo Lee &lt;jwlee2217@gmail.com&gt;
Signed-off-by: Wongi Lee &lt;qw3rtyp0@gmail.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Link: https://patch.msgid.link/ajFR1eLAIs42TN3g@DESKTOP-19IMU7U.localdomain
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
