<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/include/net, branch v5.0-rc7</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>net: fix possible overflow in __sk_mem_raise_allocated()</title>
<updated>2019-02-14T05:05:18+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2019-02-12T20:26:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5bf325a53202b8728cf7013b72688c46071e212e'/>
<id>5bf325a53202b8728cf7013b72688c46071e212e</id>
<content type='text'>
With many active TCP sockets, fat TCP sockets could fool
__sk_mem_raise_allocated() thanks to an overflow.

They would increase their share of the memory, instead
of decreasing it.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With many active TCP sockets, fat TCP sockets could fool
__sk_mem_raise_allocated() thanks to an overflow.

They would increase their share of the memory, instead
of decreasing it.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: ipv4: use a dedicated counter for icmp_v4 redirect packets</title>
<updated>2019-02-09T05:50:15+00:00</updated>
<author>
<name>Lorenzo Bianconi</name>
<email>lorenzo.bianconi@redhat.com</email>
</author>
<published>2019-02-06T18:18:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c09551c6ff7fe16a79a42133bcecba5fc2fc3291'/>
<id>c09551c6ff7fe16a79a42133bcecba5fc2fc3291</id>
<content type='text'>
According to the algorithm described in the comment block at the
beginning of ip_rt_send_redirect, the host should try to send
'ip_rt_redirect_number' ICMP redirect packets with an exponential
backoff and then stop sending them at all assuming that the destination
ignores redirects.
If the device has previously sent some ICMP error packets that are
rate-limited (e.g TTL expired) and continues to receive traffic,
the redirect packets will never be transmitted. This happens since
peer-&gt;rate_tokens will be typically greater than 'ip_rt_redirect_number'
and so it will never be reset even if the redirect silence timeout
(ip_rt_redirect_silence) has elapsed without receiving any packet
requiring redirects.

Fix it by using a dedicated counter for the number of ICMP redirect
packets that has been sent by the host

I have not been able to identify a given commit that introduced the
issue since ip_rt_send_redirect implements the same rate-limiting
algorithm from commit 1da177e4c3f4 ("Linux-2.6.12-rc2")

Signed-off-by: Lorenzo Bianconi &lt;lorenzo.bianconi@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
According to the algorithm described in the comment block at the
beginning of ip_rt_send_redirect, the host should try to send
'ip_rt_redirect_number' ICMP redirect packets with an exponential
backoff and then stop sending them at all assuming that the destination
ignores redirects.
If the device has previously sent some ICMP error packets that are
rate-limited (e.g TTL expired) and continues to receive traffic,
the redirect packets will never be transmitted. This happens since
peer-&gt;rate_tokens will be typically greater than 'ip_rt_redirect_number'
and so it will never be reset even if the redirect silence timeout
(ip_rt_redirect_silence) has elapsed without receiving any packet
requiring redirects.

Fix it by using a dedicated counter for the number of ICMP redirect
packets that has been sent by the host

I have not been able to identify a given commit that introduced the
issue since ip_rt_send_redirect implements the same rate-limiting
algorithm from commit 1da177e4c3f4 ("Linux-2.6.12-rc2")

Signed-off-by: Lorenzo Bianconi &lt;lorenzo.bianconi@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nf_tables: unbind set in rule from commit path</title>
<updated>2019-02-04T16:29:17+00:00</updated>
<author>
<name>Pablo Neira Ayuso</name>
<email>pablo@netfilter.org</email>
</author>
<published>2019-02-02T09:49:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f6ac8585897684374a19863fff21186a05805286'/>
<id>f6ac8585897684374a19863fff21186a05805286</id>
<content type='text'>
Anonymous sets that are bound to rules from the same transaction trigger
a kernel splat from the abort path due to double set list removal and
double free.

This patch updates the logic to search for the transaction that is
responsible for creating the set and disable the set list removal and
release, given the rule is now responsible for this. Lookup is reverse
since the transaction that adds the set is likely to be at the tail of
the list.

Moreover, this patch adds the unbind step to deliver the event from the
commit path.  This should not be done from the worker thread, since we
have no guarantees of in-order delivery to the listener.

This patch removes the assumption that both activate and deactivate
callbacks need to be provided.

Fixes: cd5125d8f518 ("netfilter: nf_tables: split set destruction in deactivate and destroy phase")
Reported-by: Mikhail Morfikov &lt;mmorfikov@gmail.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Anonymous sets that are bound to rules from the same transaction trigger
a kernel splat from the abort path due to double set list removal and
double free.

This patch updates the logic to search for the transaction that is
responsible for creating the set and disable the set list removal and
release, given the rule is now responsible for this. Lookup is reverse
since the transaction that adds the set is likely to be at the tail of
the list.

Moreover, this patch adds the unbind step to deliver the event from the
commit path.  This should not be done from the worker thread, since we
have no guarantees of in-order delivery to the listener.

This patch removes the assumption that both activate and deactivate
callbacks need to be provided.

Fixes: cd5125d8f518 ("netfilter: nf_tables: split set destruction in deactivate and destroy phase")
Reported-by: Mikhail Morfikov &lt;mmorfikov@gmail.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipvlan, l3mdev: fix broken l3s mode wrt local routes</title>
<updated>2019-01-31T06:13:34+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>daniel@iogearbox.net</email>
</author>
<published>2019-01-30T11:49:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d5256083f62e2720f75bb3c5a928a0afe47d6bc3'/>
<id>d5256083f62e2720f75bb3c5a928a0afe47d6bc3</id>
<content type='text'>
While implementing ipvlan l3 and l3s mode for kubernetes CNI plugin,
I ran into the issue that while l3 mode is working fine, l3s mode
does not have any connectivity to kube-apiserver and hence all pods
end up in Error state as well. The ipvlan master device sits on
top of a bond device and hostns traffic to kube-apiserver (also running
in hostns) is DNATed from 10.152.183.1:443 to 139.178.29.207:37573
where the latter is the address of the bond0. While in l3 mode, a
curl to https://10.152.183.1:443 or to https://139.178.29.207:37573
works fine from hostns, neither of them do in case of l3s. In the
latter only a curl to https://127.0.0.1:37573 appeared to work where
for local addresses of bond0 I saw kernel suddenly starting to emit
ARP requests to query HW address of bond0 which remained unanswered
and neighbor entries in INCOMPLETE state. These ARP requests only
happen while in l3s.

Debugging this further, I found the issue is that l3s mode is piggy-
backing on l3 master device, and in this case local routes are using
l3mdev_master_dev_rcu(dev) instead of net-&gt;loopback_dev as per commit
f5a0aab84b74 ("net: ipv4: dst for local input routes should use l3mdev
if relevant") and 5f02ce24c269 ("net: l3mdev: Allow the l3mdev to be
a loopback"). I found that reverting them back into using the
net-&gt;loopback_dev fixed ipvlan l3s connectivity and got everything
working for the CNI.

Now judging from 4fbae7d83c98 ("ipvlan: Introduce l3s mode") and the
l3mdev paper in [0] the only sole reason why ipvlan l3s is relying
on l3 master device is to get the l3mdev_ip_rcv() receive hook for
setting the dst entry of the input route without adding its own
ipvlan specific hacks into the receive path, however, any l3 domain
semantics beyond just that are breaking l3s operation. Note that
ipvlan also has the ability to dynamically switch its internal
operation from l3 to l3s for all ports via ipvlan_set_port_mode()
at runtime. In any case, l3 vs l3s soley distinguishes itself by
'de-confusing' netfilter through switching skb-&gt;dev to ipvlan slave
device late in NF_INET_LOCAL_IN before handing the skb to L4.

Minimal fix taken here is to add a IFF_L3MDEV_RX_HANDLER flag which,
if set from ipvlan setup, gets us only the wanted l3mdev_l3_rcv() hook
without any additional l3mdev semantics on top. This should also have
minimal impact since dev-&gt;priv_flags is already hot in cache. With
this set, l3s mode is working fine and I also get things like
masquerading pod traffic on the ipvlan master properly working.

  [0] https://netdevconf.org/1.2/papers/ahern-what-is-l3mdev-paper.pdf

Fixes: f5a0aab84b74 ("net: ipv4: dst for local input routes should use l3mdev if relevant")
Fixes: 5f02ce24c269 ("net: l3mdev: Allow the l3mdev to be a loopback")
Fixes: 4fbae7d83c98 ("ipvlan: Introduce l3s mode")
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Mahesh Bandewar &lt;maheshb@google.com&gt;
Cc: David Ahern &lt;dsa@cumulusnetworks.com&gt;
Cc: Florian Westphal &lt;fw@strlen.de&gt;
Cc: Martynas Pumputis &lt;m@lambda.lt&gt;
Acked-by: David Ahern &lt;dsa@cumulusnetworks.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
While implementing ipvlan l3 and l3s mode for kubernetes CNI plugin,
I ran into the issue that while l3 mode is working fine, l3s mode
does not have any connectivity to kube-apiserver and hence all pods
end up in Error state as well. The ipvlan master device sits on
top of a bond device and hostns traffic to kube-apiserver (also running
in hostns) is DNATed from 10.152.183.1:443 to 139.178.29.207:37573
where the latter is the address of the bond0. While in l3 mode, a
curl to https://10.152.183.1:443 or to https://139.178.29.207:37573
works fine from hostns, neither of them do in case of l3s. In the
latter only a curl to https://127.0.0.1:37573 appeared to work where
for local addresses of bond0 I saw kernel suddenly starting to emit
ARP requests to query HW address of bond0 which remained unanswered
and neighbor entries in INCOMPLETE state. These ARP requests only
happen while in l3s.

Debugging this further, I found the issue is that l3s mode is piggy-
backing on l3 master device, and in this case local routes are using
l3mdev_master_dev_rcu(dev) instead of net-&gt;loopback_dev as per commit
f5a0aab84b74 ("net: ipv4: dst for local input routes should use l3mdev
if relevant") and 5f02ce24c269 ("net: l3mdev: Allow the l3mdev to be
a loopback"). I found that reverting them back into using the
net-&gt;loopback_dev fixed ipvlan l3s connectivity and got everything
working for the CNI.

Now judging from 4fbae7d83c98 ("ipvlan: Introduce l3s mode") and the
l3mdev paper in [0] the only sole reason why ipvlan l3s is relying
on l3 master device is to get the l3mdev_ip_rcv() receive hook for
setting the dst entry of the input route without adding its own
ipvlan specific hacks into the receive path, however, any l3 domain
semantics beyond just that are breaking l3s operation. Note that
ipvlan also has the ability to dynamically switch its internal
operation from l3 to l3s for all ports via ipvlan_set_port_mode()
at runtime. In any case, l3 vs l3s soley distinguishes itself by
'de-confusing' netfilter through switching skb-&gt;dev to ipvlan slave
device late in NF_INET_LOCAL_IN before handing the skb to L4.

Minimal fix taken here is to add a IFF_L3MDEV_RX_HANDLER flag which,
if set from ipvlan setup, gets us only the wanted l3mdev_l3_rcv() hook
without any additional l3mdev semantics on top. This should also have
minimal impact since dev-&gt;priv_flags is already hot in cache. With
this set, l3s mode is working fine and I also get things like
masquerading pod traffic on the ipvlan master properly working.

  [0] https://netdevconf.org/1.2/papers/ahern-what-is-l3mdev-paper.pdf

Fixes: f5a0aab84b74 ("net: ipv4: dst for local input routes should use l3mdev if relevant")
Fixes: 5f02ce24c269 ("net: l3mdev: Allow the l3mdev to be a loopback")
Fixes: 4fbae7d83c98 ("ipvlan: Introduce l3s mode")
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Mahesh Bandewar &lt;maheshb@google.com&gt;
Cc: David Ahern &lt;dsa@cumulusnetworks.com&gt;
Cc: Florian Westphal &lt;fw@strlen.de&gt;
Cc: Martynas Pumputis &lt;m@lambda.lt&gt;
Acked-by: David Ahern &lt;dsa@cumulusnetworks.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: tls: Save iv in tls_rec for async crypto requests</title>
<updated>2019-01-29T07:05:55+00:00</updated>
<author>
<name>Dave Watson</name>
<email>davejwatson@fb.com</email>
</author>
<published>2019-01-27T00:57:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=32eb67b93c9e3cd62cb423e30b090cdd4aa8d275'/>
<id>32eb67b93c9e3cd62cb423e30b090cdd4aa8d275</id>
<content type='text'>
aead_request_set_crypt takes an iv pointer, and we change the iv
soon after setting it.  Some async crypto algorithms don't save the iv,
so we need to save it in the tls_rec for async requests.

Found by hardcoding x64 aesni to use async crypto manager (to test the async
codepath), however I don't think this combination can happen in the wild.
Presumably other hardware offloads will need this fix, but there have been
no user reports.

Fixes: a42055e8d2c30 ("Add support for async encryption of records...")
Signed-off-by: Dave Watson &lt;davejwatson@fb.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
aead_request_set_crypt takes an iv pointer, and we change the iv
soon after setting it.  Some async crypto algorithms don't save the iv,
so we need to save it in the tls_rec for async requests.

Found by hardcoding x64 aesni to use async crypto manager (to test the async
codepath), however I don't think this combination can happen in the wild.
Presumably other hardware offloads will need this fix, but there have been
no user reports.

Fixes: a42055e8d2c30 ("Add support for async encryption of records...")
Signed-off-by: Dave Watson &lt;davejwatson@fb.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ax25: fix possible use-after-free</title>
<updated>2019-01-23T19:18:00+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2019-01-22T18:40:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=63530aba7826a0f8e129874df9c4d264f9db3f9e'/>
<id>63530aba7826a0f8e129874df9c4d264f9db3f9e</id>
<content type='text'>
syzbot found that ax25 routes where not properly protected
against concurrent use [1].

In this particular report the bug happened while
copying ax25-&gt;digipeat.

Fix this problem by making sure we call ax25_get_route()
while ax25_route_lock is held, so that no modification
could happen while using the route.

The current two ax25_get_route() callers do not sleep,
so this change should be fine.

Once we do that, ax25_get_route() no longer needs to
grab a reference on the found route.

[1]
ax25_connect(): syz-executor0 uses autobind, please contact jreuter@yaina.de
BUG: KASAN: use-after-free in memcpy include/linux/string.h:352 [inline]
BUG: KASAN: use-after-free in kmemdup+0x42/0x60 mm/util.c:113
Read of size 66 at addr ffff888066641a80 by task syz-executor2/531

ax25_connect(): syz-executor0 uses autobind, please contact jreuter@yaina.de
CPU: 1 PID: 531 Comm: syz-executor2 Not tainted 5.0.0-rc2+ #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x123/0x190 mm/kasan/generic.c:191
 memcpy+0x24/0x50 mm/kasan/common.c:130
 memcpy include/linux/string.h:352 [inline]
 kmemdup+0x42/0x60 mm/util.c:113
 kmemdup include/linux/string.h:425 [inline]
 ax25_rt_autobind+0x25d/0x750 net/ax25/ax25_route.c:424
 ax25_connect.cold+0x30/0xa4 net/ax25/af_ax25.c:1224
 __sys_connect+0x357/0x490 net/socket.c:1664
 __do_sys_connect net/socket.c:1675 [inline]
 __se_sys_connect net/socket.c:1672 [inline]
 __x64_sys_connect+0x73/0xb0 net/socket.c:1672
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458099
Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f870ee22c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099
RDX: 0000000000000048 RSI: 0000000020000080 RDI: 0000000000000005
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
ax25_connect(): syz-executor4 uses autobind, please contact jreuter@yaina.de
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f870ee236d4
R13: 00000000004be48e R14: 00000000004ce9a8 R15: 00000000ffffffff

Allocated by task 526:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_kmalloc mm/kasan/common.c:496 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504
ax25_connect(): syz-executor5 uses autobind, please contact jreuter@yaina.de
 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609
 kmalloc include/linux/slab.h:545 [inline]
 ax25_rt_add net/ax25/ax25_route.c:95 [inline]
 ax25_rt_ioctl+0x3b9/0x1270 net/ax25/ax25_route.c:233
 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763
 sock_do_ioctl+0xe2/0x400 net/socket.c:950
 sock_ioctl+0x32f/0x6c0 net/socket.c:1074
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

ax25_connect(): syz-executor5 uses autobind, please contact jreuter@yaina.de
Freed by task 550:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466
 __cache_free mm/slab.c:3487 [inline]
 kfree+0xcf/0x230 mm/slab.c:3806
 ax25_rt_add net/ax25/ax25_route.c:92 [inline]
 ax25_rt_ioctl+0x304/0x1270 net/ax25/ax25_route.c:233
 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763
 sock_do_ioctl+0xe2/0x400 net/socket.c:950
 sock_ioctl+0x32f/0x6c0 net/socket.c:1074
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888066641a80
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes inside of
 96-byte region [ffff888066641a80, ffff888066641ae0)
The buggy address belongs to the page:
page:ffffea0001999040 count:1 mapcount:0 mapping:ffff88812c3f04c0 index:0x0
flags: 0x1fffc0000000200(slab)
ax25_connect(): syz-executor4 uses autobind, please contact jreuter@yaina.de
raw: 01fffc0000000200 ffffea0001817948 ffffea0002341dc8 ffff88812c3f04c0
raw: 0000000000000000 ffff888066641000 0000000100000020 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888066641980: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888066641a00: 00 00 00 00 00 00 00 00 02 fc fc fc fc fc fc fc
&gt;ffff888066641a80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                   ^
 ffff888066641b00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888066641b80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
syzbot found that ax25 routes where not properly protected
against concurrent use [1].

In this particular report the bug happened while
copying ax25-&gt;digipeat.

Fix this problem by making sure we call ax25_get_route()
while ax25_route_lock is held, so that no modification
could happen while using the route.

The current two ax25_get_route() callers do not sleep,
so this change should be fine.

Once we do that, ax25_get_route() no longer needs to
grab a reference on the found route.

[1]
ax25_connect(): syz-executor0 uses autobind, please contact jreuter@yaina.de
BUG: KASAN: use-after-free in memcpy include/linux/string.h:352 [inline]
BUG: KASAN: use-after-free in kmemdup+0x42/0x60 mm/util.c:113
Read of size 66 at addr ffff888066641a80 by task syz-executor2/531

ax25_connect(): syz-executor0 uses autobind, please contact jreuter@yaina.de
CPU: 1 PID: 531 Comm: syz-executor2 Not tainted 5.0.0-rc2+ #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x123/0x190 mm/kasan/generic.c:191
 memcpy+0x24/0x50 mm/kasan/common.c:130
 memcpy include/linux/string.h:352 [inline]
 kmemdup+0x42/0x60 mm/util.c:113
 kmemdup include/linux/string.h:425 [inline]
 ax25_rt_autobind+0x25d/0x750 net/ax25/ax25_route.c:424
 ax25_connect.cold+0x30/0xa4 net/ax25/af_ax25.c:1224
 __sys_connect+0x357/0x490 net/socket.c:1664
 __do_sys_connect net/socket.c:1675 [inline]
 __se_sys_connect net/socket.c:1672 [inline]
 __x64_sys_connect+0x73/0xb0 net/socket.c:1672
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458099
Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f870ee22c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099
RDX: 0000000000000048 RSI: 0000000020000080 RDI: 0000000000000005
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
ax25_connect(): syz-executor4 uses autobind, please contact jreuter@yaina.de
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f870ee236d4
R13: 00000000004be48e R14: 00000000004ce9a8 R15: 00000000ffffffff

Allocated by task 526:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_kmalloc mm/kasan/common.c:496 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504
ax25_connect(): syz-executor5 uses autobind, please contact jreuter@yaina.de
 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609
 kmalloc include/linux/slab.h:545 [inline]
 ax25_rt_add net/ax25/ax25_route.c:95 [inline]
 ax25_rt_ioctl+0x3b9/0x1270 net/ax25/ax25_route.c:233
 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763
 sock_do_ioctl+0xe2/0x400 net/socket.c:950
 sock_ioctl+0x32f/0x6c0 net/socket.c:1074
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

ax25_connect(): syz-executor5 uses autobind, please contact jreuter@yaina.de
Freed by task 550:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466
 __cache_free mm/slab.c:3487 [inline]
 kfree+0xcf/0x230 mm/slab.c:3806
 ax25_rt_add net/ax25/ax25_route.c:92 [inline]
 ax25_rt_ioctl+0x304/0x1270 net/ax25/ax25_route.c:233
 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763
 sock_do_ioctl+0xe2/0x400 net/socket.c:950
 sock_ioctl+0x32f/0x6c0 net/socket.c:1074
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888066641a80
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes inside of
 96-byte region [ffff888066641a80, ffff888066641ae0)
The buggy address belongs to the page:
page:ffffea0001999040 count:1 mapcount:0 mapping:ffff88812c3f04c0 index:0x0
flags: 0x1fffc0000000200(slab)
ax25_connect(): syz-executor4 uses autobind, please contact jreuter@yaina.de
raw: 01fffc0000000200 ffffea0001817948 ffffea0002341dc8 ffff88812c3f04c0
raw: 0000000000000000 ffff888066641000 0000000100000020 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888066641980: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888066641a00: 00 00 00 00 00 00 00 00 02 fc fc fc fc fc fc fc
&gt;ffff888066641a80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                   ^
 ffff888066641b00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888066641b80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "rxrpc: Allow failed client calls to be retried"</title>
<updated>2019-01-16T05:33:36+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2019-01-10T16:59:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e122d845a01ece2ddd28b2f125ef2db66b8b627a'/>
<id>e122d845a01ece2ddd28b2f125ef2db66b8b627a</id>
<content type='text'>
The changes introduced to allow rxrpc calls to be retried creates an issue
when it comes to refcounting afs_call structs.  The problem is that when
rxrpc_send_data() queues the last packet for an asynchronous call, the
following sequence can occur:

 (1) The notify_end_tx callback is invoked which causes the state in the
     afs_call to be changed from AFS_CALL_CL_REQUESTING or
     AFS_CALL_SV_REPLYING.

 (2) afs_deliver_to_call() can then process event notifications from rxrpc
     on the async_work queue.

 (3) Delivery of events, such as an abort from the server, can cause the
     afs_call state to be changed to AFS_CALL_COMPLETE on async_work.

 (4) For an asynchronous call, afs_process_async_call() notes that the call
     is complete and tried to clean up all the refs on async_work.

 (5) rxrpc_send_data() might return the amount of data transferred
     (success) or an error - which could in turn reflect a local error or a
     received error.

Synchronising the clean up after rxrpc_kernel_send_data() returns an error
with the asynchronous cleanup is then tricky to get right.

Mostly revert commit c038a58ccfd6704d4d7d60ed3d6a0fca13cf13a4.  The two API
functions the original commit added aren't currently used.  This makes
rxrpc_kernel_send_data() always return successfully if it queued the data
it was given.

Note that this doesn't affect synchronous calls since their Rx notification
function merely pokes a wait queue and does not refcounting.  The
asynchronous call notification function *has* to do refcounting and pass a
ref over the work item to avoid the need to sync the workqueue in call
cleanup.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The changes introduced to allow rxrpc calls to be retried creates an issue
when it comes to refcounting afs_call structs.  The problem is that when
rxrpc_send_data() queues the last packet for an asynchronous call, the
following sequence can occur:

 (1) The notify_end_tx callback is invoked which causes the state in the
     afs_call to be changed from AFS_CALL_CL_REQUESTING or
     AFS_CALL_SV_REPLYING.

 (2) afs_deliver_to_call() can then process event notifications from rxrpc
     on the async_work queue.

 (3) Delivery of events, such as an abort from the server, can cause the
     afs_call state to be changed to AFS_CALL_COMPLETE on async_work.

 (4) For an asynchronous call, afs_process_async_call() notes that the call
     is complete and tried to clean up all the refs on async_work.

 (5) rxrpc_send_data() might return the amount of data transferred
     (success) or an error - which could in turn reflect a local error or a
     received error.

Synchronising the clean up after rxrpc_kernel_send_data() returns an error
with the asynchronous cleanup is then tricky to get right.

Mostly revert commit c038a58ccfd6704d4d7d60ed3d6a0fca13cf13a4.  The two API
functions the original commit added aren't currently used.  This makes
rxrpc_kernel_send_data() always return successfully if it queued the data
it was given.

Note that this doesn't affect synchronous calls since their Rx notification
function merely pokes a wait queue and does not refcounting.  The
asynchronous call notification function *has* to do refcounting and pass a
ref over the work item to avoid the need to sync the workqueue in call
cleanup.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: ipv4: Fix memory leak in network namespace dismantle</title>
<updated>2019-01-15T21:33:44+00:00</updated>
<author>
<name>Ido Schimmel</name>
<email>idosch@mellanox.com</email>
</author>
<published>2019-01-09T09:57:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f97f4dd8b3bb9d0993d2491e0f22024c68109184'/>
<id>f97f4dd8b3bb9d0993d2491e0f22024c68109184</id>
<content type='text'>
IPv4 routing tables are flushed in two cases:

1. In response to events in the netdev and inetaddr notification chains
2. When a network namespace is being dismantled

In both cases only routes associated with a dead nexthop group are
flushed. However, a nexthop group will only be marked as dead in case it
is populated with actual nexthops using a nexthop device. This is not
the case when the route in question is an error route (e.g.,
'blackhole', 'unreachable').

Therefore, when a network namespace is being dismantled such routes are
not flushed and leaked [1].

To reproduce:
# ip netns add blue
# ip -n blue route add unreachable 192.0.2.0/24
# ip netns del blue

Fix this by not skipping error routes that are not marked with
RTNH_F_DEAD when flushing the routing tables.

To prevent the flushing of such routes in case #1, add a parameter to
fib_table_flush() that indicates if the table is flushed as part of
namespace dismantle or not.

Note that this problem does not exist in IPv6 since error routes are
associated with the loopback device.

[1]
unreferenced object 0xffff888066650338 (size 56):
  comm "ip", pid 1206, jiffies 4294786063 (age 26.235s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 b0 1c 62 61 80 88 ff ff  ..........ba....
    e8 8b a1 64 80 88 ff ff 00 07 00 08 fe 00 00 00  ...d............
  backtrace:
    [&lt;00000000856ed27d&gt;] inet_rtm_newroute+0x129/0x220
    [&lt;00000000fcdfc00a&gt;] rtnetlink_rcv_msg+0x397/0xa20
    [&lt;00000000cb85801a&gt;] netlink_rcv_skb+0x132/0x380
    [&lt;00000000ebc991d2&gt;] netlink_unicast+0x4c0/0x690
    [&lt;0000000014f62875&gt;] netlink_sendmsg+0x929/0xe10
    [&lt;00000000bac9d967&gt;] sock_sendmsg+0xc8/0x110
    [&lt;00000000223e6485&gt;] ___sys_sendmsg+0x77a/0x8f0
    [&lt;000000002e94f880&gt;] __sys_sendmsg+0xf7/0x250
    [&lt;00000000ccb1fa72&gt;] do_syscall_64+0x14d/0x610
    [&lt;00000000ffbe3dae&gt;] entry_SYSCALL_64_after_hwframe+0x49/0xbe
    [&lt;000000003a8b605b&gt;] 0xffffffffffffffff
unreferenced object 0xffff888061621c88 (size 48):
  comm "ip", pid 1206, jiffies 4294786063 (age 26.235s)
  hex dump (first 32 bytes):
    6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    6b 6b 6b 6b 6b 6b 6b 6b d8 8e 26 5f 80 88 ff ff  kkkkkkkk..&amp;_....
  backtrace:
    [&lt;00000000733609e3&gt;] fib_table_insert+0x978/0x1500
    [&lt;00000000856ed27d&gt;] inet_rtm_newroute+0x129/0x220
    [&lt;00000000fcdfc00a&gt;] rtnetlink_rcv_msg+0x397/0xa20
    [&lt;00000000cb85801a&gt;] netlink_rcv_skb+0x132/0x380
    [&lt;00000000ebc991d2&gt;] netlink_unicast+0x4c0/0x690
    [&lt;0000000014f62875&gt;] netlink_sendmsg+0x929/0xe10
    [&lt;00000000bac9d967&gt;] sock_sendmsg+0xc8/0x110
    [&lt;00000000223e6485&gt;] ___sys_sendmsg+0x77a/0x8f0
    [&lt;000000002e94f880&gt;] __sys_sendmsg+0xf7/0x250
    [&lt;00000000ccb1fa72&gt;] do_syscall_64+0x14d/0x610
    [&lt;00000000ffbe3dae&gt;] entry_SYSCALL_64_after_hwframe+0x49/0xbe
    [&lt;000000003a8b605b&gt;] 0xffffffffffffffff

Fixes: 8cced9eff1d4 ("[NETNS]: Enable routing configuration in non-initial namespace.")
Signed-off-by: Ido Schimmel &lt;idosch@mellanox.com&gt;
Reviewed-by: David Ahern &lt;dsahern@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
IPv4 routing tables are flushed in two cases:

1. In response to events in the netdev and inetaddr notification chains
2. When a network namespace is being dismantled

In both cases only routes associated with a dead nexthop group are
flushed. However, a nexthop group will only be marked as dead in case it
is populated with actual nexthops using a nexthop device. This is not
the case when the route in question is an error route (e.g.,
'blackhole', 'unreachable').

Therefore, when a network namespace is being dismantled such routes are
not flushed and leaked [1].

To reproduce:
# ip netns add blue
# ip -n blue route add unreachable 192.0.2.0/24
# ip netns del blue

Fix this by not skipping error routes that are not marked with
RTNH_F_DEAD when flushing the routing tables.

To prevent the flushing of such routes in case #1, add a parameter to
fib_table_flush() that indicates if the table is flushed as part of
namespace dismantle or not.

Note that this problem does not exist in IPv6 since error routes are
associated with the loopback device.

[1]
unreferenced object 0xffff888066650338 (size 56):
  comm "ip", pid 1206, jiffies 4294786063 (age 26.235s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 b0 1c 62 61 80 88 ff ff  ..........ba....
    e8 8b a1 64 80 88 ff ff 00 07 00 08 fe 00 00 00  ...d............
  backtrace:
    [&lt;00000000856ed27d&gt;] inet_rtm_newroute+0x129/0x220
    [&lt;00000000fcdfc00a&gt;] rtnetlink_rcv_msg+0x397/0xa20
    [&lt;00000000cb85801a&gt;] netlink_rcv_skb+0x132/0x380
    [&lt;00000000ebc991d2&gt;] netlink_unicast+0x4c0/0x690
    [&lt;0000000014f62875&gt;] netlink_sendmsg+0x929/0xe10
    [&lt;00000000bac9d967&gt;] sock_sendmsg+0xc8/0x110
    [&lt;00000000223e6485&gt;] ___sys_sendmsg+0x77a/0x8f0
    [&lt;000000002e94f880&gt;] __sys_sendmsg+0xf7/0x250
    [&lt;00000000ccb1fa72&gt;] do_syscall_64+0x14d/0x610
    [&lt;00000000ffbe3dae&gt;] entry_SYSCALL_64_after_hwframe+0x49/0xbe
    [&lt;000000003a8b605b&gt;] 0xffffffffffffffff
unreferenced object 0xffff888061621c88 (size 48):
  comm "ip", pid 1206, jiffies 4294786063 (age 26.235s)
  hex dump (first 32 bytes):
    6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    6b 6b 6b 6b 6b 6b 6b 6b d8 8e 26 5f 80 88 ff ff  kkkkkkkk..&amp;_....
  backtrace:
    [&lt;00000000733609e3&gt;] fib_table_insert+0x978/0x1500
    [&lt;00000000856ed27d&gt;] inet_rtm_newroute+0x129/0x220
    [&lt;00000000fcdfc00a&gt;] rtnetlink_rcv_msg+0x397/0xa20
    [&lt;00000000cb85801a&gt;] netlink_rcv_skb+0x132/0x380
    [&lt;00000000ebc991d2&gt;] netlink_unicast+0x4c0/0x690
    [&lt;0000000014f62875&gt;] netlink_sendmsg+0x929/0xe10
    [&lt;00000000bac9d967&gt;] sock_sendmsg+0xc8/0x110
    [&lt;00000000223e6485&gt;] ___sys_sendmsg+0x77a/0x8f0
    [&lt;000000002e94f880&gt;] __sys_sendmsg+0xf7/0x250
    [&lt;00000000ccb1fa72&gt;] do_syscall_64+0x14d/0x610
    [&lt;00000000ffbe3dae&gt;] entry_SYSCALL_64_after_hwframe+0x49/0xbe
    [&lt;000000003a8b605b&gt;] 0xffffffffffffffff

Fixes: 8cced9eff1d4 ("[NETNS]: Enable routing configuration in non-initial namespace.")
Signed-off-by: Ido Schimmel &lt;idosch@mellanox.com&gt;
Reviewed-by: David Ahern &lt;dsahern@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nft_flow_offload: fix interaction with vrf slave device</title>
<updated>2019-01-10T23:55:37+00:00</updated>
<author>
<name>wenxu</name>
<email>wenxu@ucloud.cn</email>
</author>
<published>2019-01-10T06:51:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=10f4e765879e514e1ce7f52ed26603047af196e2'/>
<id>10f4e765879e514e1ce7f52ed26603047af196e2</id>
<content type='text'>
In the forward chain, the iif is changed from slave device to master vrf
device. Thus, flow offload does not find a match on the lower slave
device.

This patch uses the cached route, ie. dst-&gt;dev, to update the iif and
oif fields in the flow entry.

After this patch, the following example works fine:

 # ip addr add dev eth0 1.1.1.1/24
 # ip addr add dev eth1 10.0.0.1/24
 # ip link add user1 type vrf table 1
 # ip l set user1 up
 # ip l set dev eth0 master user1
 # ip l set dev eth1 master user1

 # nft add table firewall
 # nft add flowtable f fb1 { hook ingress priority 0 \; devices = { eth0, eth1 } \; }
 # nft add chain f ftb-all {type filter hook forward priority 0 \; policy accept \; }
 # nft add rule f ftb-all ct zone 1 ip protocol tcp flow offload @fb1
 # nft add rule f ftb-all ct zone 1 ip protocol udp flow offload @fb1

Signed-off-by: wenxu &lt;wenxu@ucloud.cn&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In the forward chain, the iif is changed from slave device to master vrf
device. Thus, flow offload does not find a match on the lower slave
device.

This patch uses the cached route, ie. dst-&gt;dev, to update the iif and
oif fields in the flow entry.

After this patch, the following example works fine:

 # ip addr add dev eth0 1.1.1.1/24
 # ip addr add dev eth1 10.0.0.1/24
 # ip link add user1 type vrf table 1
 # ip l set user1 up
 # ip l set dev eth0 master user1
 # ip l set dev eth1 master user1

 # nft add table firewall
 # nft add flowtable f fb1 { hook ingress priority 0 \; devices = { eth0, eth1 } \; }
 # nft add chain f ftb-all {type filter hook forward priority 0 \; policy accept \; }
 # nft add rule f ftb-all ct zone 1 ip protocol tcp flow offload @fb1
 # nft add rule f ftb-all ct zone 1 ip protocol udp flow offload @fb1

Signed-off-by: wenxu &lt;wenxu@ucloud.cn&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Remove 'type' argument from access_ok() function</title>
<updated>2019-01-04T02:57:57+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-01-04T02:57:57+00:00</published>
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Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
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<pre>
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
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