<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net, branch v4.4.233</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>ipv6: check skb-&gt;protocol before lookup for nexthop</title>
<updated>2020-08-21T08:53:07+00:00</updated>
<author>
<name>WANG Cong</name>
<email>xiyou.wangcong@gmail.com</email>
</author>
<published>2017-04-25T21:37:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=00068bf855c14f764e708649116847736d13783d'/>
<id>00068bf855c14f764e708649116847736d13783d</id>
<content type='text'>
commit 199ab00f3cdb6f154ea93fa76fd80192861a821d upstream.

Andrey reported a out-of-bound access in ip6_tnl_xmit(), this
is because we use an ipv4 dst in ip6_tnl_xmit() and cast an IPv4
neigh key as an IPv6 address:

        neigh = dst_neigh_lookup(skb_dst(skb),
                                 &amp;ipv6_hdr(skb)-&gt;daddr);
        if (!neigh)
                goto tx_err_link_failure;

        addr6 = (struct in6_addr *)&amp;neigh-&gt;primary_key; // &lt;=== HERE
        addr_type = ipv6_addr_type(addr6);

        if (addr_type == IPV6_ADDR_ANY)
                addr6 = &amp;ipv6_hdr(skb)-&gt;daddr;

        memcpy(&amp;fl6-&gt;daddr, addr6, sizeof(fl6-&gt;daddr));

Also the network header of the skb at this point should be still IPv4
for 4in6 tunnels, we shold not just use it as IPv6 header.

This patch fixes it by checking if skb-&gt;protocol is ETH_P_IPV6: if it
is, we are safe to do the nexthop lookup using skb_dst() and
ipv6_hdr(skb)-&gt;daddr; if not (aka IPv4), we have no clue about which
dest address we can pick here, we have to rely on callers to fill it
from tunnel config, so just fall to ip6_route_output() to make the
decision.

Fixes: ea3dc9601bda ("ip6_tunnel: Add support for wildcard tunnel endpoints.")
Reported-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Tested-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Cc: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Alessio Balsini &lt;balsini@android.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 199ab00f3cdb6f154ea93fa76fd80192861a821d upstream.

Andrey reported a out-of-bound access in ip6_tnl_xmit(), this
is because we use an ipv4 dst in ip6_tnl_xmit() and cast an IPv4
neigh key as an IPv6 address:

        neigh = dst_neigh_lookup(skb_dst(skb),
                                 &amp;ipv6_hdr(skb)-&gt;daddr);
        if (!neigh)
                goto tx_err_link_failure;

        addr6 = (struct in6_addr *)&amp;neigh-&gt;primary_key; // &lt;=== HERE
        addr_type = ipv6_addr_type(addr6);

        if (addr_type == IPV6_ADDR_ANY)
                addr6 = &amp;ipv6_hdr(skb)-&gt;daddr;

        memcpy(&amp;fl6-&gt;daddr, addr6, sizeof(fl6-&gt;daddr));

Also the network header of the skb at this point should be still IPv4
for 4in6 tunnels, we shold not just use it as IPv6 header.

This patch fixes it by checking if skb-&gt;protocol is ETH_P_IPV6: if it
is, we are safe to do the nexthop lookup using skb_dst() and
ipv6_hdr(skb)-&gt;daddr; if not (aka IPv4), we have no clue about which
dest address we can pick here, we have to rely on callers to fill it
from tunnel config, so just fall to ip6_route_output() to make the
decision.

Fixes: ea3dc9601bda ("ip6_tunnel: Add support for wildcard tunnel endpoints.")
Reported-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Tested-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Cc: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Alessio Balsini &lt;balsini@android.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>mac80211: fix misplaced while instead of if</title>
<updated>2020-08-21T08:53:05+00:00</updated>
<author>
<name>Johannes Berg</name>
<email>johannes.berg@intel.com</email>
</author>
<published>2020-08-03T09:02:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0e69dff673edf0812e3c4a173b38797927b48e24'/>
<id>0e69dff673edf0812e3c4a173b38797927b48e24</id>
<content type='text'>
commit 5981fe5b0529ba25d95f37d7faa434183ad618c5 upstream.

This never was intended to be a 'while' loop, it should've
just been an 'if' instead of 'while'. Fix this.

I noticed this while applying another patch from Ben that
intended to fix a busy loop at this spot.

Cc: stable@vger.kernel.org
Fixes: b16798f5b907 ("mac80211: mark station unauthorized before key removal")
Reported-by: Ben Greear &lt;greearb@candelatech.com&gt;
Link: https://lore.kernel.org/r/20200803110209.253009ae41ff.I3522aad099392b31d5cf2dcca34cbac7e5832dde@changeid
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.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 5981fe5b0529ba25d95f37d7faa434183ad618c5 upstream.

This never was intended to be a 'while' loop, it should've
just been an 'if' instead of 'while'. Fix this.

I noticed this while applying another patch from Ben that
intended to fix a busy loop at this spot.

Cc: stable@vger.kernel.org
Fixes: b16798f5b907 ("mac80211: mark station unauthorized before key removal")
Reported-by: Ben Greear &lt;greearb@candelatech.com&gt;
Link: https://lore.kernel.org/r/20200803110209.253009ae41ff.I3522aad099392b31d5cf2dcca34cbac7e5832dde@changeid
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>net: Set fput_needed iff FDPUT_FPUT is set</title>
<updated>2020-08-21T08:53:03+00:00</updated>
<author>
<name>Miaohe Lin</name>
<email>linmiaohe@huawei.com</email>
</author>
<published>2020-08-06T11:53:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f1f8c3303a663e2f685c4d6842e8b2832c67b3cf'/>
<id>f1f8c3303a663e2f685c4d6842e8b2832c67b3cf</id>
<content type='text'>
[ Upstream commit ce787a5a074a86f76f5d3fd804fa78e01bfb9e89 ]

We should fput() file iff FDPUT_FPUT is set. So we should set fput_needed
accordingly.

Fixes: 00e188ef6a7e ("sockfd_lookup_light(): switch to fdget^W^Waway from fget_light")
Signed-off-by: Miaohe Lin &lt;linmiaohe@huawei.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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit ce787a5a074a86f76f5d3fd804fa78e01bfb9e89 ]

We should fput() file iff FDPUT_FPUT is set. So we should set fput_needed
accordingly.

Fixes: 00e188ef6a7e ("sockfd_lookup_light(): switch to fdget^W^Waway from fget_light")
Signed-off-by: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net/nfc/rawsock.c: add CAP_NET_RAW check.</title>
<updated>2020-08-21T08:53:03+00:00</updated>
<author>
<name>Qingyu Li</name>
<email>ieatmuttonchuan@gmail.com</email>
</author>
<published>2020-08-10T01:51:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=de7c8ab8cb412d21ffdac94a99ef2f29f7802fd1'/>
<id>de7c8ab8cb412d21ffdac94a99ef2f29f7802fd1</id>
<content type='text'>
[ Upstream commit 26896f01467a28651f7a536143fe5ac8449d4041 ]

When creating a raw AF_NFC socket, CAP_NET_RAW needs to be checked first.

Signed-off-by: Qingyu Li &lt;ieatmuttonchuan@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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 26896f01467a28651f7a536143fe5ac8449d4041 ]

When creating a raw AF_NFC socket, CAP_NET_RAW needs to be checked first.

Signed-off-by: Qingyu Li &lt;ieatmuttonchuan@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;
</pre>
</div>
</content>
</entry>
<entry>
<title>Bluetooth: add a mutex lock to avoid UAF in do_enale_set</title>
<updated>2020-08-21T08:52:58+00:00</updated>
<author>
<name>Lihong Kou</name>
<email>koulihong@huawei.com</email>
</author>
<published>2020-06-23T12:28:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3f568251c5dbe7d2ac7dd32f26743b5f47ce1efc'/>
<id>3f568251c5dbe7d2ac7dd32f26743b5f47ce1efc</id>
<content type='text'>
[ Upstream commit f9c70bdc279b191da8d60777c627702c06e4a37d ]

In the case we set or free the global value listen_chan in
different threads, we can encounter the UAF problems because
the method is not protected by any lock, add one to avoid
this bug.

BUG: KASAN: use-after-free in l2cap_chan_close+0x48/0x990
net/bluetooth/l2cap_core.c:730
Read of size 8 at addr ffff888096950000 by task kworker/1:102/2868

CPU: 1 PID: 2868 Comm: kworker/1:102 Not tainted 5.5.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 01/01/2011
Workqueue: events do_enable_set
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 print_address_description+0x74/0x5c0 mm/kasan/report.c:374
 __kasan_report+0x149/0x1c0 mm/kasan/report.c:506
 kasan_report+0x26/0x50 mm/kasan/common.c:641
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135
 l2cap_chan_close+0x48/0x990 net/bluetooth/l2cap_core.c:730
 do_enable_set+0x660/0x900 net/bluetooth/6lowpan.c:1074
 process_one_work+0x7f5/0x10f0 kernel/workqueue.c:2264
 worker_thread+0xbbc/0x1630 kernel/workqueue.c:2410
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Allocated by task 2870:
 save_stack mm/kasan/common.c:72 [inline]
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc+0x118/0x1c0 mm/kasan/common.c:515
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529
 kmem_cache_alloc_trace+0x221/0x2f0 mm/slab.c:3551
 kmalloc include/linux/slab.h:555 [inline]
 kzalloc include/linux/slab.h:669 [inline]
 l2cap_chan_create+0x50/0x320 net/bluetooth/l2cap_core.c:446
 chan_create net/bluetooth/6lowpan.c:640 [inline]
 bt_6lowpan_listen net/bluetooth/6lowpan.c:959 [inline]
 do_enable_set+0x6a4/0x900 net/bluetooth/6lowpan.c:1078
 process_one_work+0x7f5/0x10f0 kernel/workqueue.c:2264
 worker_thread+0xbbc/0x1630 kernel/workqueue.c:2410
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Freed by task 2870:
 save_stack mm/kasan/common.c:72 [inline]
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:337 [inline]
 __kasan_slab_free+0x12e/0x1e0 mm/kasan/common.c:476
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10d/0x220 mm/slab.c:3757
 l2cap_chan_destroy net/bluetooth/l2cap_core.c:484 [inline]
 kref_put include/linux/kref.h:65 [inline]
 l2cap_chan_put+0x170/0x190 net/bluetooth/l2cap_core.c:498
 do_enable_set+0x66c/0x900 net/bluetooth/6lowpan.c:1075
 process_one_work+0x7f5/0x10f0 kernel/workqueue.c:2264
 worker_thread+0xbbc/0x1630 kernel/workqueue.c:2410
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff888096950000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 0 bytes inside of
 2048-byte region [ffff888096950000, ffff888096950800)
The buggy address belongs to the page:
page:ffffea00025a5400 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00027d1548 ffffea0002397808 ffff8880aa400e00
raw: 0000000000000000 ffff888096950000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809694ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88809694ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
&gt;ffff888096950000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888096950080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888096950100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Reported-by: syzbot+96414aa0033c363d8458@syzkaller.appspotmail.com
Signed-off-by: Lihong Kou &lt;koulihong@huawei.com&gt;
Signed-off-by: Marcel Holtmann &lt;marcel@holtmann.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 f9c70bdc279b191da8d60777c627702c06e4a37d ]

In the case we set or free the global value listen_chan in
different threads, we can encounter the UAF problems because
the method is not protected by any lock, add one to avoid
this bug.

BUG: KASAN: use-after-free in l2cap_chan_close+0x48/0x990
net/bluetooth/l2cap_core.c:730
Read of size 8 at addr ffff888096950000 by task kworker/1:102/2868

CPU: 1 PID: 2868 Comm: kworker/1:102 Not tainted 5.5.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 01/01/2011
Workqueue: events do_enable_set
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 print_address_description+0x74/0x5c0 mm/kasan/report.c:374
 __kasan_report+0x149/0x1c0 mm/kasan/report.c:506
 kasan_report+0x26/0x50 mm/kasan/common.c:641
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135
 l2cap_chan_close+0x48/0x990 net/bluetooth/l2cap_core.c:730
 do_enable_set+0x660/0x900 net/bluetooth/6lowpan.c:1074
 process_one_work+0x7f5/0x10f0 kernel/workqueue.c:2264
 worker_thread+0xbbc/0x1630 kernel/workqueue.c:2410
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Allocated by task 2870:
 save_stack mm/kasan/common.c:72 [inline]
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc+0x118/0x1c0 mm/kasan/common.c:515
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529
 kmem_cache_alloc_trace+0x221/0x2f0 mm/slab.c:3551
 kmalloc include/linux/slab.h:555 [inline]
 kzalloc include/linux/slab.h:669 [inline]
 l2cap_chan_create+0x50/0x320 net/bluetooth/l2cap_core.c:446
 chan_create net/bluetooth/6lowpan.c:640 [inline]
 bt_6lowpan_listen net/bluetooth/6lowpan.c:959 [inline]
 do_enable_set+0x6a4/0x900 net/bluetooth/6lowpan.c:1078
 process_one_work+0x7f5/0x10f0 kernel/workqueue.c:2264
 worker_thread+0xbbc/0x1630 kernel/workqueue.c:2410
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Freed by task 2870:
 save_stack mm/kasan/common.c:72 [inline]
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:337 [inline]
 __kasan_slab_free+0x12e/0x1e0 mm/kasan/common.c:476
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10d/0x220 mm/slab.c:3757
 l2cap_chan_destroy net/bluetooth/l2cap_core.c:484 [inline]
 kref_put include/linux/kref.h:65 [inline]
 l2cap_chan_put+0x170/0x190 net/bluetooth/l2cap_core.c:498
 do_enable_set+0x66c/0x900 net/bluetooth/6lowpan.c:1075
 process_one_work+0x7f5/0x10f0 kernel/workqueue.c:2264
 worker_thread+0xbbc/0x1630 kernel/workqueue.c:2410
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff888096950000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 0 bytes inside of
 2048-byte region [ffff888096950000, ffff888096950800)
The buggy address belongs to the page:
page:ffffea00025a5400 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00027d1548 ffffea0002397808 ffff8880aa400e00
raw: 0000000000000000 ffff888096950000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809694ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88809694ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
&gt;ffff888096950000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888096950080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888096950100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Reported-by: syzbot+96414aa0033c363d8458@syzkaller.appspotmail.com
Signed-off-by: Lihong Kou &lt;koulihong@huawei.com&gt;
Signed-off-by: Marcel Holtmann &lt;marcel@holtmann.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>udp: drop corrupt packets earlier to avoid data corruption</title>
<updated>2020-08-21T08:52:57+00:00</updated>
<author>
<name>Dexuan Cui</name>
<email>decui@microsoft.com</email>
</author>
<published>2020-07-28T01:55:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c514bb4147e2c667cf82f9aa7689cf442078c13f'/>
<id>c514bb4147e2c667cf82f9aa7689cf442078c13f</id>
<content type='text'>
The v4.4 stable kernel lacks this bugfix:
commit 327868212381 ("make skb_copy_datagram_msg() et.al. preserve -&gt;msg_iter on error").
As a result, the v4.4 kernel can deliver corrupt data to the application
when a corrupt UDP packet is closely followed by a valid UDP packet: the
same invocation of the recvmsg() syscall can deliver the corrupt packet's
UDP payload to the application with the UDP payload length and the
"from IP/Port" of the valid packet.

Details:

For a UDP packet longer than 76 bytes (see the v5.8-rc6 kernel's
include/linux/skbuff.h:3951), Linux delays the UDP checksum verification
until the application invokes the syscall recvmsg().

In the recvmsg() syscall handler, while Linux is copying the UDP payload
to the application's memory, it calculates the UDP checksum. If the
calculated checksum doesn't match the received checksum, Linux drops the
corrupt UDP packet, and then starts to process the next packet (if any),
and if the next packet is valid (i.e. the checksum is correct), Linux
will copy the valid UDP packet's payload to the application's receiver
buffer.

The bug is: before Linux starts to copy the valid UDP packet, the data
structure used to track how many more bytes should be copied to the
application memory is not reset to what it was when the application just
entered the kernel by the syscall! Consequently, only a small portion or
none of the valid packet's payload is copied to the application's
receive buffer, and later when the application exits from the kernel,
actually most of the application's receive buffer contains the payload
of the corrupt packet while recvmsg() returns the length of the UDP
payload of the valid packet.

For the mainline kernel, the bug was fixed in commit 327868212381,
but unluckily the bugfix is only backported to v4.9+. It turns out
backporting 327868212381 to v4.4 means that some supporting patches
must be backported first, so the overall changes seem too big, so the
alternative is performs the csum validation earlier and drops the
corrupt packets earlier.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.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>
The v4.4 stable kernel lacks this bugfix:
commit 327868212381 ("make skb_copy_datagram_msg() et.al. preserve -&gt;msg_iter on error").
As a result, the v4.4 kernel can deliver corrupt data to the application
when a corrupt UDP packet is closely followed by a valid UDP packet: the
same invocation of the recvmsg() syscall can deliver the corrupt packet's
UDP payload to the application with the UDP payload length and the
"from IP/Port" of the valid packet.

Details:

For a UDP packet longer than 76 bytes (see the v5.8-rc6 kernel's
include/linux/skbuff.h:3951), Linux delays the UDP checksum verification
until the application invokes the syscall recvmsg().

In the recvmsg() syscall handler, while Linux is copying the UDP payload
to the application's memory, it calculates the UDP checksum. If the
calculated checksum doesn't match the received checksum, Linux drops the
corrupt UDP packet, and then starts to process the next packet (if any),
and if the next packet is valid (i.e. the checksum is correct), Linux
will copy the valid UDP packet's payload to the application's receiver
buffer.

The bug is: before Linux starts to copy the valid UDP packet, the data
structure used to track how many more bytes should be copied to the
application memory is not reset to what it was when the application just
entered the kernel by the syscall! Consequently, only a small portion or
none of the valid packet's payload is copied to the application's
receive buffer, and later when the application exits from the kernel,
actually most of the application's receive buffer contains the payload
of the corrupt packet while recvmsg() returns the length of the UDP
payload of the valid packet.

For the mainline kernel, the bug was fixed in commit 327868212381,
but unluckily the bugfix is only backported to v4.9+. It turns out
backporting 327868212381 to v4.4 means that some supporting patches
must be backported first, so the overall changes seem too big, so the
alternative is performs the csum validation earlier and drops the
corrupt packets earlier.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipv6: fix memory leaks on IPV6_ADDRFORM path</title>
<updated>2020-08-21T08:52:56+00:00</updated>
<author>
<name>Cong Wang</name>
<email>xiyou.wangcong@gmail.com</email>
</author>
<published>2020-07-25T22:40:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=462ec03e6e8c491208ae63b5011a2559719a8445'/>
<id>462ec03e6e8c491208ae63b5011a2559719a8445</id>
<content type='text'>
[ Upstream commit 8c0de6e96c9794cb523a516c465991a70245da1c ]

IPV6_ADDRFORM causes resource leaks when converting an IPv6 socket
to IPv4, particularly struct ipv6_ac_socklist. Similar to
struct ipv6_mc_socklist, we should just close it on this path.

This bug can be easily reproduced with the following C program:

  #include &lt;stdio.h&gt;
  #include &lt;string.h&gt;
  #include &lt;sys/types.h&gt;
  #include &lt;sys/socket.h&gt;
  #include &lt;arpa/inet.h&gt;

  int main()
  {
    int s, value;
    struct sockaddr_in6 addr;
    struct ipv6_mreq m6;

    s = socket(AF_INET6, SOCK_DGRAM, 0);
    addr.sin6_family = AF_INET6;
    addr.sin6_port = htons(5000);
    inet_pton(AF_INET6, "::ffff:192.168.122.194", &amp;addr.sin6_addr);
    connect(s, (struct sockaddr *)&amp;addr, sizeof(addr));

    inet_pton(AF_INET6, "fe80::AAAA", &amp;m6.ipv6mr_multiaddr);
    m6.ipv6mr_interface = 5;
    setsockopt(s, SOL_IPV6, IPV6_JOIN_ANYCAST, &amp;m6, sizeof(m6));

    value = AF_INET;
    setsockopt(s, SOL_IPV6, IPV6_ADDRFORM, &amp;value, sizeof(value));

    close(s);
    return 0;
  }

Reported-by: ch3332xr@gmail.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Cong Wang &lt;xiyou.wangcong@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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 8c0de6e96c9794cb523a516c465991a70245da1c ]

IPV6_ADDRFORM causes resource leaks when converting an IPv6 socket
to IPv4, particularly struct ipv6_ac_socklist. Similar to
struct ipv6_mc_socklist, we should just close it on this path.

This bug can be easily reproduced with the following C program:

  #include &lt;stdio.h&gt;
  #include &lt;string.h&gt;
  #include &lt;sys/types.h&gt;
  #include &lt;sys/socket.h&gt;
  #include &lt;arpa/inet.h&gt;

  int main()
  {
    int s, value;
    struct sockaddr_in6 addr;
    struct ipv6_mreq m6;

    s = socket(AF_INET6, SOCK_DGRAM, 0);
    addr.sin6_family = AF_INET6;
    addr.sin6_port = htons(5000);
    inet_pton(AF_INET6, "::ffff:192.168.122.194", &amp;addr.sin6_addr);
    connect(s, (struct sockaddr *)&amp;addr, sizeof(addr));

    inet_pton(AF_INET6, "fe80::AAAA", &amp;m6.ipv6mr_multiaddr);
    m6.ipv6mr_interface = 5;
    setsockopt(s, SOL_IPV6, IPV6_JOIN_ANYCAST, &amp;m6, sizeof(m6));

    value = AF_INET;
    setsockopt(s, SOL_IPV6, IPV6_ADDRFORM, &amp;value, sizeof(value));

    close(s);
    return 0;
  }

Reported-by: ch3332xr@gmail.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Cong Wang &lt;xiyou.wangcong@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;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipv4: Silence suspicious RCU usage warning</title>
<updated>2020-08-21T08:52:56+00:00</updated>
<author>
<name>Ido Schimmel</name>
<email>idosch@mellanox.com</email>
</author>
<published>2020-07-29T08:37:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c11d02fcd23c7764b3e0e27825765f47e673f08e'/>
<id>c11d02fcd23c7764b3e0e27825765f47e673f08e</id>
<content type='text'>
[ Upstream commit 83f3522860f702748143e022f1a546547314c715 ]

fib_trie_unmerge() is called with RTNL held, but not from an RCU
read-side critical section. This leads to the following warning [1] when
the FIB alias list in a leaf is traversed with
hlist_for_each_entry_rcu().

Since the function is always called with RTNL held and since
modification of the list is protected by RTNL, simply use
hlist_for_each_entry() and silence the warning.

[1]
WARNING: suspicious RCU usage
5.8.0-rc4-custom-01520-gc1f937f3f83b #30 Not tainted
-----------------------------
net/ipv4/fib_trie.c:1867 RCU-list traversed in non-reader section!!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by ip/164:
 #0: ffffffff85a27850 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0

stack backtrace:
CPU: 0 PID: 164 Comm: ip Not tainted 5.8.0-rc4-custom-01520-gc1f937f3f83b #30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack+0x100/0x184
 lockdep_rcu_suspicious+0x153/0x15d
 fib_trie_unmerge+0x608/0xdb0
 fib_unmerge+0x44/0x360
 fib4_rule_configure+0xc8/0xad0
 fib_nl_newrule+0x37a/0x1dd0
 rtnetlink_rcv_msg+0x4f7/0xbd0
 netlink_rcv_skb+0x17a/0x480
 rtnetlink_rcv+0x22/0x30
 netlink_unicast+0x5ae/0x890
 netlink_sendmsg+0x98a/0xf40
 ____sys_sendmsg+0x879/0xa00
 ___sys_sendmsg+0x122/0x190
 __sys_sendmsg+0x103/0x1d0
 __x64_sys_sendmsg+0x7d/0xb0
 do_syscall_64+0x54/0xa0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fc80a234e97
Code: Bad RIP value.
RSP: 002b:00007ffef8b66798 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc80a234e97
RDX: 0000000000000000 RSI: 00007ffef8b66800 RDI: 0000000000000003
RBP: 000000005f141b1c R08: 0000000000000001 R09: 0000000000000000
R10: 00007fc80a2a8ac0 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007ffef8b67008 R15: 0000556fccb10020

Fixes: 0ddcf43d5d4a ("ipv4: FIB Local/MAIN table collapse")
Signed-off-by: Ido Schimmel &lt;idosch@mellanox.com&gt;
Reviewed-by: Jiri Pirko &lt;jiri@mellanox.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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 83f3522860f702748143e022f1a546547314c715 ]

fib_trie_unmerge() is called with RTNL held, but not from an RCU
read-side critical section. This leads to the following warning [1] when
the FIB alias list in a leaf is traversed with
hlist_for_each_entry_rcu().

Since the function is always called with RTNL held and since
modification of the list is protected by RTNL, simply use
hlist_for_each_entry() and silence the warning.

[1]
WARNING: suspicious RCU usage
5.8.0-rc4-custom-01520-gc1f937f3f83b #30 Not tainted
-----------------------------
net/ipv4/fib_trie.c:1867 RCU-list traversed in non-reader section!!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by ip/164:
 #0: ffffffff85a27850 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0

stack backtrace:
CPU: 0 PID: 164 Comm: ip Not tainted 5.8.0-rc4-custom-01520-gc1f937f3f83b #30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack+0x100/0x184
 lockdep_rcu_suspicious+0x153/0x15d
 fib_trie_unmerge+0x608/0xdb0
 fib_unmerge+0x44/0x360
 fib4_rule_configure+0xc8/0xad0
 fib_nl_newrule+0x37a/0x1dd0
 rtnetlink_rcv_msg+0x4f7/0xbd0
 netlink_rcv_skb+0x17a/0x480
 rtnetlink_rcv+0x22/0x30
 netlink_unicast+0x5ae/0x890
 netlink_sendmsg+0x98a/0xf40
 ____sys_sendmsg+0x879/0xa00
 ___sys_sendmsg+0x122/0x190
 __sys_sendmsg+0x103/0x1d0
 __x64_sys_sendmsg+0x7d/0xb0
 do_syscall_64+0x54/0xa0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fc80a234e97
Code: Bad RIP value.
RSP: 002b:00007ffef8b66798 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc80a234e97
RDX: 0000000000000000 RSI: 00007ffef8b66800 RDI: 0000000000000003
RBP: 000000005f141b1c R08: 0000000000000001 R09: 0000000000000000
R10: 00007fc80a2a8ac0 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007ffef8b67008 R15: 0000556fccb10020

Fixes: 0ddcf43d5d4a ("ipv4: FIB Local/MAIN table collapse")
Signed-off-by: Ido Schimmel &lt;idosch@mellanox.com&gt;
Reviewed-by: Jiri Pirko &lt;jiri@mellanox.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cfg80211: check vendor command doit pointer before use</title>
<updated>2020-08-21T08:52:56+00:00</updated>
<author>
<name>Julian Squires</name>
<email>julian@cipht.net</email>
</author>
<published>2020-07-06T21:13:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=75bb09a58bf6957e9cecd411ceca19ed05113bef'/>
<id>75bb09a58bf6957e9cecd411ceca19ed05113bef</id>
<content type='text'>
[ Upstream commit 4052d3d2e8f47a15053320bbcbe365d15610437d ]

In the case where a vendor command does not implement doit, and has no
flags set, doit would not be validated and a NULL pointer dereference
would occur, for example when invoking the vendor command via iw.

I encountered this while developing new vendor commands.  Perhaps in
practice it is advisable to always implement doit along with dumpit,
but it seems reasonable to me to always check doit anyway, not just
when NEED_WDEV.

Signed-off-by: Julian Squires &lt;julian@cipht.net&gt;
Link: https://lore.kernel.org/r/20200706211353.2366470-1-julian@cipht.net
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.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 4052d3d2e8f47a15053320bbcbe365d15610437d ]

In the case where a vendor command does not implement doit, and has no
flags set, doit would not be validated and a NULL pointer dereference
would occur, for example when invoking the vendor command via iw.

I encountered this while developing new vendor commands.  Perhaps in
practice it is advisable to always implement doit along with dumpit,
but it seems reasonable to me to always check doit anyway, not just
when NEED_WDEV.

Signed-off-by: Julian Squires &lt;julian@cipht.net&gt;
Link: https://lore.kernel.org/r/20200706211353.2366470-1-julian@cipht.net
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net/9p: validate fds in p9_fd_open</title>
<updated>2020-08-21T08:52:56+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-07-10T08:57:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d20fc4079f20f87fe6bda8b3dc0ac55e746346bb'/>
<id>d20fc4079f20f87fe6bda8b3dc0ac55e746346bb</id>
<content type='text'>
[ Upstream commit a39c46067c845a8a2d7144836e9468b7f072343e ]

p9_fd_open just fgets file descriptors passed in from userspace, but
doesn't verify that they are valid for read or writing.  This gets
cought down in the VFS when actually attempting a read or write, but
a new warning added in linux-next upsets syzcaller.

Fix this by just verifying the fds early on.

Link: http://lkml.kernel.org/r/20200710085722.435850-1-hch@lst.de
Reported-by: syzbot+e6f77e16ff68b2434a2c@syzkaller.appspotmail.com
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
[Dominique: amend goto as per Doug Nazar's review]
Signed-off-by: Dominique Martinet &lt;asmadeus@codewreck.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 a39c46067c845a8a2d7144836e9468b7f072343e ]

p9_fd_open just fgets file descriptors passed in from userspace, but
doesn't verify that they are valid for read or writing.  This gets
cought down in the VFS when actually attempting a read or write, but
a new warning added in linux-next upsets syzcaller.

Fix this by just verifying the fds early on.

Link: http://lkml.kernel.org/r/20200710085722.435850-1-hch@lst.de
Reported-by: syzbot+e6f77e16ff68b2434a2c@syzkaller.appspotmail.com
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
[Dominique: amend goto as per Doug Nazar's review]
Signed-off-by: Dominique Martinet &lt;asmadeus@codewreck.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
